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A reagent‐controlled diastereodivergent copper‐catalyzed borylative difunctionalization is reported. The formation of Lewis adducts that guide selectivity is commonly invoked in organic reaction mechanisms. Using density functional theory calculations, we identified BpinBdan as a sterically similar and less Lewis acidic alternative to B2pin2. Using a newly developed borylative aldol domino reaction as the proof‐of‐concept, we demonstrate a change in stereochemical outcome by a simple change of borylating reagent—B2pin2 affords the diastereomer associated with coordination control while BpinBdan overturns this mode of binding. We show that this strategy can be generalized to other scaffolds and, more importantly, that BpinBdan does not alter the diastereomeric outcome of the reaction when coordination is not involved. BpinBdan can be viewed as a mechanistic probe for coordination in future copper‐catalyzed borylation reactions. [ABSTRACT FROM AUTHOR]

The small, lipophilic tetrafluoroborate anion is ubiquitous in the imidazol(in)ium and iminium precursors to N‐heterocyclic carbenes (NHCs), including cyclic (alkyl)(amino)carbenes (CAACs). Its symmetrical distribution of charge over four highly electronegative fluorine atoms confers high stability, attenuating basicity while shielding the boron center. Here we report that this inertness does not withstand the nucleophilicity of free carbenes, when combined with a polarizing lithium cation. Reaction of CAAC ⋅ HBF4 salts with LiN(SiMe3)2, a protocol widely used to liberate free CAACs, generates zwitterionic CAAC‐BF3 adducts within minutes at 80 °C, or hours at room temperature, even for bulky N‐diisopropylphenyl (DIPP) CAACs. Imidazol(in)ium tetrafluoroborates likewise form NHC‐BF3 adducts in excellent yields. [ABSTRACT FROM AUTHOR]

Cu‐catalyzed asymmetric allylic borylation of 3,3'‐disubstituted 1‐vinylcyclobutan‐1‐ols renders axially chiral allylborane systems, with high asymmetric induction for both enantiomers, by precise selection of the cis or trans substrate. The enantioenriched alkylidenecyclobutanes served as chiral platform to prove the conceptually challenging transference of the axial‐to‐point chirality through two new stereocenters and one pseudoasymmetric carbon generated via diastereoconvergent allylation of aldehydes, without enantioselective erosion. [ABSTRACT FROM AUTHOR]

The selective borylation of specific C−H bonds in organic synthesis remains a formidable challenge. In this study, we present a novel spirobipyridine ligand that features a binaphthyl backbone. This ligand facilitates the iridium‐catalyzed selective C−H borylation of benzene derivatives. The ligand is designed with "side‐arm‐wall" substituents that allow vicinal di‐ or multi‐substituted benzene derivatives to approach metal center and effectively block other reactive sites by non‐covalent interactions with substrates. The effectiveness of this strategy is demonstrated by the successful selective distal C−H activation of various alkaloids and its broad compatibility with functional groups. [ABSTRACT FROM AUTHOR]

Comprehensive Summary Key Scientists We reviewed works on radical borylation reactions since 2020 from two aspects. 1. Borylation from alkyl or aryl radicals: This approach involves the generation of alkyl or aryl radicals from various precursors such as halides and carboxylic acids, followed by their reaction with diboron reagents to form boron esters. 2. Borylation from boron‐centered radicals: This approach involves generating boron‐centered radicals, which then react with substrates to achieve borylation. [ABSTRACT FROM AUTHOR]

Site‐selective C−H bond functionalization of arenes at the para position remains extremely challenging primarily due to its relative inaccessibility from the catalytic site. As a consequence, it is significantly restricted to limited molecular scaffolds. Herein, we report a method for the para‐C−H borylation of aromatic aldimines and benzylamines using commercially available ligands under iridium catalysis. The established method displays excellent para selectivity for variously substituted aromatic aldimines, benzylamines and bioactive molecules. Based on several control experiments, it is proposed that a Lewis acid−base interaction between the nitrogen and boron functionality guides the para selectivity via a steric shield for the aromatic aldimines, where Bpin acts as a transient directing group. However, the steric shield of the in situ generated N−Bpin moiety controlled the overall selectivity for the para borylation of benzylamines. [ABSTRACT FROM AUTHOR]

Comprehensive Summary Key Scientists Boronate esters are highly valued in synthetic and pharmaceutical industries for their versatility in creating C—C and C—X bonds. They also find applications as catalysts in chemical transformations as well as stimuli‐responsive materials in materials science. Some alkyl boronates themselves also show promising applications in medicinal chemistry. In the past few decades, chemists have been devoted to developing new methods or new starting materials for synthesizing boronate esters. Carboxylic acids and their derivatives are privileged chemical entities due to their readily availability or natural abundance, structural diversity, and chemical stability. Hence, the transformation of carboxylic acid and their derivatives to alkyl/aryl boronate esters has seen its fast development in the past decade. This review summarized the state‐to‐art development of decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives to aryl and alkyl boronate esters.The decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives started only in the past decade. In 2016, the decarbonylative borylation of carboxylic esters and amides was reported by Zhuangzhi Shi and Magnus Reuping's groups. Then, in 2017, studies on the decarboxylative borylation of redox‐active esters such as NHPI esters started to receive increasing attention by Aggarwal, Baran, Fu, Glorius, and Li's groups. From 2018 to 2023, large numbers of studies on the decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives using transition‐metal‐catalyst, organo‐catalyst, or under photochemical or electrochemical conditions emerged. Due to space limitations, only pictures of scientists who have contributed more than two works in this area are shown herein. [ABSTRACT FROM AUTHOR]

Stereospecific approaches allow the introduction of a stereogenic center into complex organic molecules using optically active reagents. Among these, the Pd-catalyzed stereospecific cross-coupling of chiral alkylboron compounds stands out as a highly effective tool for organic synthesis. In parallel with advances in the development of borylation technology, the strategy has recently witnessed a growth in its applicability. This account aims to review the progress on Pd-catalyzed stereospecific B -alkyl Suzuki–Miyaura cross-coupling, tracing its evolution from early breakthroughs to the most recent advances. 1 Introduction 2 Cross-Coupling of 1° Alkylboron Compounds 3 Cross-Coupling of Benzylboron Compounds 4 Cross-Coupling of Allyl- and Propargylboron Compounds 5 Cross-Coupling of Other Types of Activated 2° Alkylboron Compounds 6 Cross-Coupling of Unactivated 2° Alkylboron Compounds 7 Conclusion and Outlook [ABSTRACT FROM AUTHOR]

Reported here is the iridium-catalyzed regio- and enantio-selective secondary benzylic C–H borylation using benzothiazole as the directing group. Various monosubstituted 2-arylalkylbenzo[ d ]thiazole were well-tolerated, affording the corresponding products in moderate to good yields with good enantioselectivity. The C–B bond in one boryl-ated product could undergo stereospecific transformations to form a series of C–C and C–heteroatom bonds. [ABSTRACT FROM AUTHOR]

Nickel-catalyzed C–H bond functionalization reactions provide an impressive alternative to those with noble metal catalysts due to their unique reactivity and low cost. However, the regioselective C(sp2)–H borylation reaction of arenes accomplished by nickel catalyst remains limited. We herein disclose a silyl-directed ortho C(sp2)–H borylation of substituted arenes with a Ni(cod)2/PMe3/KHMDS catalyst system. Using readily available starting materials, this protocol provides easy access to ortho-borylated benzylic hydrosilanes bearing flexible substitution patterns. These products can serve as versatile building blocks for the synthesis of sila or sila/borine heterocycles under mild conditions. Control experiments and DFT calculations suggest that a catalytic amount of base prompts the formation of Ni(II)-Bpin-ate complex, likely related to the C(sp2)–H bond activation. This borylation reaction might follow an unusual Ni(II)/Ni(IV) catalytic cycle. Nickel-catalyzed C–H bond functionalization reactions provide an impressive alternative to those with noble metal catalysts but the regioselective C(sp2)−H borylation reaction of arenes accomplished by nickel catalyst remains challenging. Here the authors disclose a silyl-directed ortho C(sp2)−H borylation of substituted arenes with a Ni(cod)2/PMe3/KHMDS catalyst system. [ABSTRACT FROM AUTHOR]

Expanding the diversity of multi‐macrocyclic nanocarbons, particularly those with all‐benzene scaffolds, represents intriguing yet challenging synthetic tasks. Complementary to the existing synthetic approaches, here we report an efficient and modular post‐functionalization strategy that employs iridium‐catalyzed C−H borylation of the highly strained meta‐cycloparaphenylenes (mCPPs) and an mCPP‐derived catenane. Based on the functionalized macrocyclic synthons, a number of novel all‐benzene topological structures including linear and cyclic chains, polycatenane, and pretzelane have been successfully prepared and characterized, thereby showcasing the synthetic utility and potential of the post‐functionalization strategy. [ABSTRACT FROM AUTHOR]

A mild Pd-catalyzed three-component cascade cyclization functionalization of o-iodostyrenes, internal alkynes and boron reagents is presented. The transformation is driven by a controlled reaction sequence of intermolecular carbopalladation, intramolecular Heck-type cyclization, and a borylation process to give versatile boryl-functionalized indene skeletons in a selective fashion. Significantly, (Bpin)2, (Bneop)2 and CH2(Bpin)2 as boron sources are all tolerated. Additionally, the synthetic utility of this approach is demonstrated by gram-scale synthesis and synthetic transformations. [ABSTRACT FROM AUTHOR]

C–H bond activation is a crucial synthetic strategy widely utilized in both academic and industrial settings. Due to the strong and kinetically inert nature of the C–H bond, its functionalization typically requires metal-based catalysts. This review highlights the most significant advancements in homogeneously catalyzed reactions using pincer complexes with metals from groups 8–10, capable of promoting challenging C–H activation, published since 2010. In particular, it focuses on C–H bond activation for borylation, isomerization, and dehydrogenation, among other processes, discussing their scope and mechanistic insights. [ABSTRACT FROM AUTHOR]

Borylation of haloarenes is one of the most important methodologies to synthesize borylated arenes. Generally, borylation of haloarenes occurs smoothly at the sterically less hindered para or meta position by the use of a transition metal catalyst or a photoredox catalyst or under basic conditions. This study reports on the ortho -specific and chemoselective borylation of ortho -iodoarene possessing carboxamide under visible-light irradiation. When a haloarene containing both C–I and C–X bonds is employed as a substrate, another C–X bond (not ortho) remains intact during the reaction. Mechanistic studies revealed that the key to the success of this reaction is the generation of a diboron-bridged five-membered ring as a transition state, in which the diboron-bridged five-membered ring and the benzene ring in the transition state are perpendicular to each other, owing to steric repulsion by the iodine atom at the ortho position. This chemoselectivity is suitable for the synthesis of borylated building blocks. [ABSTRACT FROM AUTHOR]

Borylation of a tungsten‐bound N2 ligand and halide abstraction provides access to a cationic complex with an unprecedented linear NNBR ligand. This complex undergoes [3+2] cycloaddition with azides, and an unexpected chain‐extension reaction with an iminoborane, leading to a complex with a five‐atom B/N chain. These two [NNBR]‐containing complexes, inorganic analogues of E. O. Fischer's alkynylcarbynes, are very rare examples of molecules containing all‐inorganic chains of sp‐hybridized atoms. [ABSTRACT FROM AUTHOR]

The copper catalyzed hydroboration of alkynes with B2pin2 was studied by in detail studies of individual relevant steps along the catalytic pathway. A number of reaction steps were retraced by in situ NMR spectroscopy as well as central intermediates and side‐products were isolated and comprehensively characterized. A copper boryl complex is central to the catalytic process by inserting the terminal alkyne substrate into the B−Cu bond. The selectivity of this step – depending on the NHC auxiliary ligand – determines the α/β selectivity observed in the product. The latter complex is protonated by the auxiliary alcohol reagent resulting in hydroboration product formation and formation of a Cu alkoxido complex. Reaction of the latter with B2pin2 results in the regeneration of the central copper boryl complex. This alcoholysis step depends on the acidity of the alcohol, in particular on the relative acidity of the alcohol vs. the alkyne substrate. A number of side reactions leading to the hydrogenation product of the alkyne substrate and a bis hydroborated product were identified and studied in some detail. It is concluded that the performance of a particular catalytic system depends crucially on the relative acidities of the reagents and generalizations may be difficult. [ABSTRACT FROM AUTHOR]

This research article uses density functional theory (DFT) to study photoinduced borylation. This work examined the electron donor‐acceptor complex (EDA) of bis(catecholato)diboron with different redox‐active leaving groups and bis(pinacol)diboron with aryl N‐hydroxyphthalimide. The results of these DFT studies show the complex ratio of B2cat2 and N, N‐dimethylacetamide (DMA) should be 1 : 2 which is consistent with the experimental results in the literature. We further proposed a reaction mechanism and calculated the energies associated with each step. [ABSTRACT FROM AUTHOR]

Chemoselective monoborylation of methane in high yield is a grand challenge. We have developed a metal–organic framework confined pyridylimine-iridium hydride catalyst, which is efficient in methane C–H borylation using bis(pinacolato)diboron to afford methyl boronic acid pinacol ester in 98% GC-yield at 130 °C with a TON of 196. Mechanistic investigation suggests the oxidative addition of methane to IrIII(Bpin)2(H) species to form IrV(Bpin)2(CH3)(H)2 as the turnover limiting step. [ABSTRACT FROM AUTHOR]

Silylation of aryl and alkenyl triflates is found to occur readily with silylboronic esters as a silicon source under copper catalysis. The silyl moieties are exclusively installed into the organic frameworks through the preferential generation of a silylcopper species, wherein base-mediated direct borylation is totally suppressed. The combined use of tri-n-butylphosphine and 4,4′-diphenyl-2,2′-bipyridine as a ligand combination turned out to be indispensable for achieving the high catalytic activity. [ABSTRACT FROM AUTHOR]

This article discusses the synthesis of fluorinated molecules, which are important in drug discovery and crop science. The authors focus on the regiodivergent borylation of fluorinated alkynes using copper catalysis. They describe the optimization of reaction conditions and the scope and limitations of the borylation reactions. The authors also developed a palladium-catalyzed Suzuki-Miyaura cross-coupling reaction to selectively functionalize the borylated olefins. The article provides a proposed mechanism for the reactions and discusses the scalability of the reactions. [Extracted from the article]

An air-stable B3,N3-containing dibenzobisanthene (8) was prepared in 29% yield by heating a 1,3,5-tri(azasilaanthryl)benzene (5) with BBr3 (180 °C). Under these conditions, the reaction does not stop after threefold SiMe2/BBr exchange but proceeds further via two rearrangement and two intramolecular C–H borylation steps. Some mechanistic details were unveiled by using smaller model systems and applying lower reaction temperatures. According to X-ray crystallography, compound 8 has a helically distorted scaffold. Due to its multiple resonance structure, it shows a narrow-band blue-green emission (λem = 493 nm; ΦPL = 84%; FWHM = 0.20 eV; THF); samples measured in PMMA gave prompt and delayed fluorescence lifetimes of 10.7 ns and 136 μs, respectively. The optical properties of 8 and of structurally related species were also investigated by quantum-chemical means: most of these compounds exhibit a small energy gap ΔEST between the lowest excited singlet (S1) and triplet (T1) states and a non-negligible spin–orbit coupling (SOC) between S1 and T1/T2, demonstrating their potential as thermally activated delayed fluorescence (TADF) emitters. [ABSTRACT FROM AUTHOR]

ortho-N-Substituted pyridinium cations with the weakly coordinating anion [B(C6F5)4]− have been studied and crucial structural features in the sp2 C–H borylation catalysis of 3-methylthiophene have been identified. The electron-deficiency of the aromatic core of the cation is essential for activity together with accessible protons. The spectroscopic yield of the borylation of 3-methylthiophene with catecholborane (CatBH) was optimized up to 86% and the method was further applied to other substrates such as N-alkylbenzenes. A mechanistic DFT study revealed the rate-limiting step in the catalysis to be the liberation of molecular H2 (ΔG‡ = 27.5 kcal mol−1), whereas the overall reaction was found to be exergonic by 5.1 kcal mol−1. [ABSTRACT FROM AUTHOR]

C-H borylation is a powerful strategy for the construction of C-B bonds due to the synthetic versatility of C-B bonds. Various transition metals affect the powerful functionalization of C-H bonds, of which Ir is the most common. Substrate-directed methods have enabled directed Ir-catalyzed C-H borylation at the ortho position. Amongst the powerful directing groups in Ir-catalyzed C-H borylation are N-containing carbocyclic systems. This review covers substrate-directed Ir-catalyzed ortho-C-H borylation of aromatic C(sp2)-H bonds in N-containing carbocyclic compounds, such as anilines, amides, benzyl amines, hydrazones, and triazines. [ABSTRACT FROM AUTHOR]

We report a class of isolable bis‐cyclometallated iridium precatalysts (ImIr) and their use in regioselective ortho−C−H borylation of aromatic, heteroaromatic, acrylic, and aliphatic systems. The catalysts consist of two imine ligands and an acetate coordinated to an iridium (III) center. The isolable character of ImIr warrants its compatibility with high‐throughput experimentation, a prerequisite for applications in late‐stage functionalization (LSF) of complex substrates. Initial mechanistic studies point towards an inner‐sphere mechanism involving bis‐cyclometallated species shedding light on the general mechanistic understanding of ortho‐selective C−H borylations. [ABSTRACT FROM AUTHOR]

Dearomative partial reduction is an extraordinary approach for transforming benzenoid arenes and has been well‐known for many decades, as exemplified by the dehydrogenation of Birch reduction and the hydroarylation of Crich addition. Despite its remarkable importance in synthesis, this field has experienced slow progress over the last half‐century. However, a revival has been observed with the recent introduction of electrochemical and photochemical methods. In this Minireview, we summarize the recent advancements in dearomative partial reduction of benzenoid arenes, including dihydrogenation, hydroalkylation, arylation, alkenylation, amination, borylation and others. Further, the intriguing utilization of dearomative partial reduction in the synthesis of natural products is also emphasized. It is anticipated that this Minireview will stimulate further progress in arene dearomative transformations. [ABSTRACT FROM AUTHOR]

This article explores the development of a method for the asymmetric β-borylation of α,β-unsaturated acyl silanes using copper catalysis. The authors conducted experiments to optimize the reaction conditions and found that a ligand-free reaction produced the best results. They also investigated the range of the reaction and successfully synthesized various β-boryl acyl silanes with different substituents. The authors suggest that the inclusion of Li(acac) helps prevent undesired cleavage of the acyl silane moiety. Overall, this research provides valuable insights into the optimization and scope of a Cu I -catalyzed conjugate borylation reaction, which may have potential applications in further studies of bifunctional molecules. [Extracted from the article]

This article provides an overview of the field of C–H activation, which involves breaking carbon-hydrogen bonds in organic molecules to form new bonds. It specifically focuses on the use of main group elements, such as boron and phosphorus, as catalysts for these reactions. The article discusses the mechanisms by which these main group systems can cleave C–H bonds and explores specific approaches using boron- and phosphorus-based systems. It also compares these main group processes to C–H activation reactions using late-transition-metal complexes. The article introduces a researcher at Colorado State University who is dedicated to exploring new reactions in heterocyclic chemistry, with a particular emphasis on utilizing main group elements and dearomatized intermediates. [Extracted from the article]

This document explores the use of late-stage functionalization (LSF) in medicinal chemistry, specifically focusing on the modification of drug molecules towards the end of synthesis. LSF allows for the rapid generation of diverse analogues and the exploration of structure-activity relationships (SAR). The document provides case studies of LSF applications, including the modification of compounds targeting the BTK enzyme and the GPR40 receptor. The authors emphasize the potential of LSF in expanding the chemical space around lead molecules and improving pharmacokinetic properties. They also discuss future opportunities for LSF in more complex synthetic contexts and the modification of other modalities such as peptides and oligonucleotides. [Extracted from the article]

The defluoroborylation of fluoroarenes by chromium-catalyzed cleavage of unactivated C–F bonds is described. The reaction uses HBpin as the boron source, low-cost and commercially available chromium salt as the precatalyst, and terpyridine as a crucial ligand, providing a protocol with atom-efficient benefits and a wide range of applicable substrates for the functionalization of aryl C–F bonds. Preliminary mechanistic studies indicate that an unprecedented Cr-catalyzed magnesiation of the unactivated C–F bond occurred. The generated arylmagnesium intermediates then participated in the subsequent borylation reaction. The application of the strategy in the preparation of valuable derivatives is demonstrated by the late-stage functionalization of boronate ester groups. [ABSTRACT FROM AUTHOR]

The borylation of aryl substituted pyridines is an effective way of preparing B-N doped conjugated organic frameworks. Trihaloborane Lewis acids are often employed for this protocol, and may require further functionalization to replace the remaining halides on boron. We report a new, fully characterized, electrophilic borylating agent, (C6F5)2B(κ2-NTf2), that smoothly incorporates a -B(C6F5)2 unit into the model substrate 2-phenylpyridine. To demonstrate its utility in preparing more complex B-N doped structures, we use it to prepare seven examples of the 6a, 13a-diaza-7,14-dibora-dibenzo[a,h]pyrene framework, with substituents of varying donor properties. The structural, redox, and photophysical properties of this new family of B-N doped polycyclic hydrocarbon compounds were probed experimentally and computationally. [ABSTRACT FROM AUTHOR]

The enormous and widespread use of organoboronic acids has prompted the development of innovative synthetic methodologies to meet the demands on structural diversity and functional group tolerance. The existing photoinduced defunctionalization radical borylation, typically focused on the conversion of one C-X bond (X= Br, I, or other leaving group) into only one C-B bond. Herein, we disclose a divergent radical dechloroborylation reaction enabled by dinuclear gold catalysis with visible light irradiation. A wide range of structurally diverse alkyl boronic, α-chloroboronic, and gem-diboronic esters can be synthesized in moderate to good yields (up to 92%). Its synthetic robustness is further demonstrated on a preparative scale and applied to late-stage diversification of complex molecules. The process hinges on a C-Cl bond relay activation in readily available gem-dichloroalkanes through inner-sphere electron transfer, overcoming the redox potential limits of unreactive alkyl chlorides. The widespread use of organoboronic acids has prompted the development of synthetic methodologies to meet the demands on structural diversity and functional group tolerance. Herein, the authors disclose a divergent radical dechloroborylation reaction enabled by dinuclear gold catalysis with visible light irradiation. [ABSTRACT FROM AUTHOR]

A strategy of C3/C4 and C5/C4 bis-C–H functionalization of furfural and 5-hydroxymethylfurfural is presented. This task has been accomplished by the initial iridium-catalyzed C–H borylation of furfural, equipped with an appropriate imine function. Depending on the nature of the ligand employed, the borylation takes place selectively at C3 or C5, the products serving in turn as partners in Suzuki-Miyaura cross-couplings. After aldehyde function regeneration, some of the resulting heterobiaryl compounds underwent a, C3- or C5-directed, C4-selective Pd-catalyzed Fujiwara-Moritani olefination. These hitherto unknown serial C3/C4 and C5/C4 bis C–H functionalization strategies allow the straightforward conversion of the bio-sourced platform molecules furfural and 5-hydroxymethylfurfural into tri- and tetra-substituted furaldehyde derivatives.

4,4′‐Biazulene is a potentially attractive key component of an axially chiral biaryl compound, however, its structure and properties have not been clarified owing to the lack of its efficient synthesis. We report a breakthrough in the reliable synthesis of 4,4′‐biazulene, which is achieved by the access to azulen‐4‐ylboronic acid pinacol ester and 4‐iodoazulene as novel key synthetic intermediates for the Suzuki‐Miyaura cross‐coupling reaction. The X‐ray crystallographic analysis of 4,4′‐biazulene confirmed its axial chirality. The enantiomers of 4,4′‐biazulene were successfully resolved by HPLC on the chiral stationary phase column. The kinetic experiments and DFT calculations indicate that the racemization energy barrier of 4,4′‐biazulene is comparable to that of 1,1′‐binaphthyl. [ABSTRACT FROM AUTHOR]

1,4‐BN‐doped polycyclic aromatic hydrocarbons (PAHs) have emerged as very promising emitters in organic light‐emitting diodes (OLEDs) due to their narrowband emission spectra that may find application in high‐definition displays. While considerable research has focused on investigating the properties of these materials, less attention has been placed on their synthetic methodology. Here we developed an efficient synthetic method for 1,4‐BN‐doped PAHs, which enables sustainable production of narrowband organic emitting materials. By strategically introducing substituents, such as methyl, tert‐butyl, phenyl, and chloride, at the C5 position of the 1,3‐benzenediamine substrates, we achieved remarkable regioselective borylation in the para‐position of the substituted moiety. This approach facilitated the synthesis of a diverse range of 1,4‐BN‐doped PAHs emitters with good yields and exceptional regioselectivity. The synthetic method demonstrated excellent scalability for large‐scale production and enabled late‐stage transformation of the borylated products. Mechanistic investigations provided valuable insights into the pivotal roles of electron effect and steric hindrance effect in achieving highly efficient regioselective borylation. Moreover, the outstanding device performance of the synthesized compounds 10 b and 6 z, underscores the practicality and significance of the developed method. [ABSTRACT FROM AUTHOR]

Due to boron's metalloid properties, aromatic boron reagents are prevalent synthetic intermediates. The direct borylation of aryl C-H bonds for producing aromatic boron compounds offers an appealing, one-step solution. Despite significant advances in this field, achieving regioselective aryl C-H bond borylation using simple and readily available starting materials still remains a challenge. In this work, we attempted to enhance the reactivity of the electron-donor-acceptor (EDA) complex by selecting different bases to replace the organic base (NEt3) used in our previous research. To our delight, when using NH4HCO3 as the base, we have achieved a mild visible-light-mediated aromatic C-H bond borylation reaction with exceptional regioselectivity (rr > 40:1 to single isomers). Compared with our previous borylation methodologies, this protocol provides a more efficient and broader scope for aryl C-H bond borylation through the use of N-Bromosuccinimide. The protocol's good functional-group tolerance and excellent regioselectivity enable the functionalization of a variety of biologically relevant compounds and novel cascade transformations. Mechanistic experiments and theoretical calculations conducted in this study have indicated that, for certain arenes, the aryl C-H bond borylation might proceed through a new reaction mechanism, which involves the formation of a novel transient EDA complex. [ABSTRACT FROM AUTHOR]

An ideal approach for the construction of aryl boron compounds is to selectively replace a C–H bond in arenes with a C–B bond, and controlling regioselectivity is one of the most challenging aspects of these transformations. Herein, we report an iridium-catalyzed trialkoxysilane protecting group-assisted regioselective C–H borylation of arenes, including derivatives of benzaldehydes, acetophenones, benzoic acids, benzyl alcohols, phenols, aryl silanes, benzyl silanes, and multi-functionalized aromatic rings are all well tolerated and gave the para -selective C–H borylation products in a short time without the requirement of inert gases atmosphere. The site-selective C–H borylation can be adjustable by installing the developed trialkoxysilane protecting group on different functional groups on one aromatic ring. Importantly, the preparation process of the trialkoxychlorosilane is efficient and scalable. Mechanistic and computational studies reveal that the steric hindrance of the trialkoxysilane protecting group plays a key role in dictating the para-selectivity. Controlling regioselectivity is one of the most challenging aspects for the construction of aryl boron compounds, and there are few practical and general strategies for such transformations. Here, the authors report an iridium-catalyzed trialkoxysilane protecting group-assisted regioselective C–H borylation with various aromatic compounds. [ABSTRACT FROM AUTHOR]

A convenient and operationally trivial protocol to access synthetically versatile vinylboronates through CuI catalyzed hydroboration and carboboration of alkynes utilizing bis(pinacolato)diboron (B2pin2) as the boron precursor in a 1, 10‐phenanthroline (phen) ligand environment is reported. This is a highly efficient and practical method for the synthesis of regio‐ and stereoselective (E)‐β‐vinylboronates from simple aromatic and aliphatic alkynes. These organoboron compounds have further been utilized for the synthesis of allyl‐vinyl ethers, which are potential starting materials for the Claisen rearrangement via an improved CuII mediated coupling of allyl alcohols and vinylboronates. The vinylboronates were also subjected to Suzuki‐Miyaura cross coupling reaction, allowing access to the corresponding tri‐ and tetra‐substituted alkenes with good isolated yields. [ABSTRACT FROM AUTHOR]

PNP pincers represent some of the most well-studied ligand systems in coordination chemistry owing to their high thermal and chemical stability, and the predictable metal coordination geometries of associated metal complexes. Examples of first-row transition metal complexes bearing acridine-based PNP pincer ligands are extremely rare. This study reports the preparation and structural authentication of acridine-based copper(I) PNP complexes, which reveal the profound effects that the steric bulk of methylene-tethered P-substituents has on metal centre coordination number and geometry. The capacity of these systems to mediate copper-catalysed alkyne hydroboration and the borylation of aryl halides is also investigated. [ABSTRACT FROM AUTHOR]

Skeletal editing of N‐heterocycles has recently received considerable attention, and the introduction of boron atom into heterocycles often results in positive property changes. However, direct enlargement of N‐heterocycles through boron atom insertion is rarely reported in the literature. Here, we report a N‐heterocyclic editing reaction through the combination boron atom insertion and C−H borylation, accessing the fused‐BN‐heterocycles. The synthetic potential of this chemistry was demonstrated by substrate scope and late‐stage diversification of products. [ABSTRACT FROM AUTHOR]

Herein, the selective ortho‐ and meta‐C−H bond borylation of NH‐aryl sulfoximines is reported. Regioselectivity is achieved by the choice of commercially available ligands giving fast excess to valuable borylated aryl sulfoximine building blogs. The utility of the borylated products is demonstrated for the formation of C−O, C−C, C−N, C−D, and C−I bonds. [ABSTRACT FROM AUTHOR]

This document provides a detailed account of the development of a photocatalyzed reaction for the synthesis of the antifungal drug tavaborole. The researchers optimized the reaction conditions and achieved a yield of up to 81% using a flow reactor. The method has potential applications in the synthesis of other drugs, and the chemical shifts and spectra of the synthesized tavaborole are also included. This research contributes to the advancement of green synthetic methods in pharmaceutical manufacturing. [Extracted from the article]

A catalyst‐free 1,2‐diborylation of aryllithium with tetra(o‐tolyl)diborane(4) has been achieved, giving a series of 1,2‐diborylaryl lithium species in excellent yields under mild reaction conditions, which leads to 1,2‐di(tolyl)borylarenes in 60–91 % yields upon treatment with the hydride‐abstracting reagent. In these transformations, one sp2 C−H of arene is activated and both boryl units are utilized to build two new (sp2)C−B bonds. This represents a new strategy for selective arene diborylation. Density functional theory (DFT) calculations suggest that an aromatic nucleophilic substitution is a key step in the formation of the products. [ABSTRACT FROM AUTHOR]

Hydrogen atom transfer (HAT) processes can overcome the strong bond dissociation energies (BDEs) of inert C(sp3)–H bonds and thereby convert feedstock alkanes into value-added fine chemicals. Nevertheless, the high reactivity of HAT reagents, coupled with the small differences among various C(sp3)–H bond strengths, renders site-selective transformations of straight-chain alkanes a great challenge. Here, we present a photocatalytic intermolecular radical sampling process for the iron-catalyzed borylation of terminal C(sp3)–H bonds in substrates with small steric hindrance, including unbranched alkanes. Mechanistic investigations have revealed that the reaction proceeds through a reversible HAT process, followed by a selective borylation of carbon radicals. A boron-sulfoxide complex may contribute to the high terminal regioselectivity observed. [ABSTRACT FROM AUTHOR]

Functionalized 3‐azabicyclo[3.1.0]hexanes are highly interesting for their physiochemical and pharmacological properties. We report an unprecedented direct bridge‐head C(sp3)−H borylation by cooperative iridium/aluminum catalysis. This reaction proceeds under mild conditions in good yields with moderate to complete site selectivities. Moreover, the use of a BINOL‐based chiral aluminum catalyst renders the synthesis of enantioenriched alkylboronate products. We also disclose its synthetic utility through rapid diversifications without any loss of the stereochemical information. [ABSTRACT FROM AUTHOR]

Abstract This research article uses density functional theory (DFT) to study photoinduced borylation. This work examined the electron donor‐acceptor complex (EDA) of bis(catecholato)diboron with different redox‐active leaving groups and bis(pinacol)diboron with aryl N‐hydroxyphthalimide. The results of these DFT studies show the complex ratio of B2cat2 and N, N‐dimethylacetamide (DMA) should be 1 : 2 which is consistent with the experimental results in the literature. We further proposed a reaction mechanism and calculated the energies associated with each step.

We herein describe a protocol to synthesize trifluoromethylated alkyl boronates from alkenes by the mutual activation of the Togni II and the bis(catecholato)diboron reagents in the absence of any catalyst and additives. This reaction enables synthesizing a series of trifluoromethylated alkyl boronates using unactivated alkenes, including natural products and drug derivatives, in a regioselective manner. Moreover, the synthetic utility of the boronic ester present in the product allows access to a range of trifluoromethyl containing compounds. The radical trapping and gas detection experiments reveal that the more Lewis acidic diboron reagent determines the rapid formation of trifluoromethyl and boron centered radicals. [ABSTRACT FROM AUTHOR]

We found that gold nanoparticles function as single‐electron transfer catalysts to promote decarboxylative cross‐coupling between N‐hydroxy phthalimide esters and disilanes or diborons. A variety of disilanes coupled with alkyl radicals could be generated from N‐hydroxy phthalimide esters via single‐electron reduction by active carbon‐supported gold nanoparticle catalysts to afford diverse alkylsilanes without the need for external bases. Furthermore, the present gold catalytic system was also effective for decarboxylative carbon‐boron coupling to afford alkyl boronates. A detailed mechanistic investigation revealed that single‐electron transfer mediated by supported gold nanoparticles enabled the generation of alkyl radical and silyl radical, thereby enabling radical cross‐coupling. The reusability and environmentally‐friendly nature of supported gold catalyst as well as the scalability of the reaction system enable the practical transformation of carboxylic acid derivatives into value‐added organosilicon and organoboron compounds. [ABSTRACT FROM AUTHOR]

A novel synthetic approach toward pinacol boronate used as a precursor in the recent radiosynthesis of [18F]rucaparib is described in this study. The Heck reaction of an ortho‐iodoaniline derivative bearing a chloride group at the meta‐position with acrylonitrile produced the desired (E)‐2‐aminocinnamonitrile derivative. The subsequent cyanide‐catalyzed imino‐Stetter reaction of aldimine derived from the obtained 2‐aminocinnamonitrile and aldehyde afforded the required trisubstituted indole‐3‐acetonitrile. The reduction of the nitrile group with cobalt boride followed by the construction of an azepinone scaffold generated indoloazepinone bearing a chloride substituent at the C6‐position of the indole scaffold. The Suzuki–Miyaura borylation of the chloride substituent produced pinacol boronate previously used in the synthesis of [18F]rucaparib. Detailed outcomes of different approaches using different 2‐aminocinnamonitriles were discussed as well. [ABSTRACT FROM AUTHOR]

We report herein a mild stereo‐ and regioselective dearomatization of quinolines using the simple low valent HCo(N2)(PPh3)3 complex that exhibits labile ligands. Conditions to form selectively, at room temperature, high‐valued 1,4‐bis‐borylated tetrahydroquinolines from simple starting heteroaromatic compounds have been developed. The efficient and selective functionalization of a large scope of quinolines bearing various electron‐donating or electron‐withdrawing substituents is presented, as well as the post‐modification of the resulting C−B bond. NMR and labelling studies are consistent with a cascade mechanism pathway, starting from an in situ generated paramagnetic bis‐quinoline cobalt(I) hydride complex. A first quinoline dearomatization followed by a cobalt(I)‐catalyzed Markovnikov hydroboration of the remaining double bond allows the introduction of the boronic ester group only at C4 position. DFT calculations particularly highlight the importance of the cobalt triplet state throughout the reaction pathway, and bring some rationalization for the observed C4 selective borylation. [ABSTRACT FROM AUTHOR]

Catalysts that distinguish between electronically distinct carbon-hydrogen (C–H) bonds without relying on steric effects or directing groups are challenging to design. In this work, cobalt precatalysts supported by N-alkyl-imidazole–substituted pyridine dicarbene (ACNC) pincer ligands are described that enable undirected, remote borylation of fluoroaromatics and expansion of scope to include electron-rich arenes, pyridines, and tri- and difluoromethoxylated arenes, thereby addressing one of the major limitations of first-row transition metal C–H functionalization catalysts. Mechanistic studies established a kinetic preference for C–H bond activation at the meta-position despite cobalt-aryl complexes resulting from ortho C–H activation being thermodynamically preferred. Switchable site selectivity in C–H borylation as a function of the boron reagent was thereby preliminarily demonstrated using a single precatalyst. [ABSTRACT FROM AUTHOR]