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In this paper, we report a palladium‐catalyzed dual C–H activation of N‐phenyl‐1H‐indole‐3‐carboxamides for the synthesis of 5,11‐dihydro‐6H‐indolo[3,2‐c]quinolin‐6‐ones. The optimal reaction conditions were to use 20 mol % of Pd(TFA)2 as the catalyst, 2.0 equivalents of Cu(OAc)2 as the oxidant, 1.0 equivalent of K3PO4 as the base, and 3.0 equivalents of PivOH as the additive in DMF/dioxane (1: 9). When carried out at 120 °C for 24 h, the reaction could provide nineteen target indoloquinolinones in modest to excellent yields, including the N,N′‐dimethylated and N,N′‐unsubstituted products which are inaccessible by the reported C–H activation methodologies. The dual C–H activation reaction was also applicable to N‐phenyl‐1H‐indole‐2‐carboxamides and formed the corresponding 5,7‐dihydro‐6H‐indolo[2,3‐c]quinolin‐6‐ones. A plausible reaction mechanism based on the data from the control experiments and the literatures was proposed to account for the transformation. [ABSTRACT FROM AUTHOR]

In recent years, transition metal-catalyzed C–H activation and site-selective functionalization have been considered to be valuable synthetic tactics to functionalize organic compounds containing multiple C–H bonds. Pyrene is one of the privileged and notorious polycyclic aromatic hydrocarbons. Pyrene and its derivatives have found applications in various branches of chemical sciences, including organic chemistry, chemical biology, supramolecular sciences, and material sciences. Given the importance of pyrene derivatives, several classical methods, including the C–H functionalization method, have been developed for synthesizing modified pyrene scaffolds. This review attempts to cover the recent developments in the area pertaining to the modification of the pyrene motif through the C–H activation process and the functionalization of C–H bonds present in the pyrene motif, leading to functionalized pyrenes. [ABSTRACT FROM AUTHOR]

A single-step method for aniline formation was examined. Using a vanadate catalyst with an iron oxide co-catalyst and hydroxylamine hydrochloride as the amine source, an up to 90% yield of aniline was obtained with high selectivity. Further study showed that the overall reaction was pseudo-second order in terms of hydroxylamine concentration. Regioselective H-D exchange experiments suggest that the C-N bond formation step occurs via an irreversible electrophilic pathway. Based on all of the key observations, a mechanism is proposed. [ABSTRACT FROM AUTHOR]

With the promise of streamlining the synthesis of complex target molecules, direct functionalization or direct coupling of organic molecules, especially through transition-metal-catalyzed C-H activation, [1] has recently gained much popularity. Under standard reaction conditions using the most popular ligand, dtbpy (4,4'-di- I tert i -butyl-2,2'-bipyridyl), the borylation proceeds at the less crowded sites; when multiple C-H bonds with similar steric environments are available, then the catalyst differentiates them poorly, resulting in low selectivity. Steric control, site selectivity, remote control, transition-metal catalysis, C-H activation Keywords: steric control; site selectivity; remote control; C-H activation; transition-metal catalysis EN steric control site selectivity remote control C-H activation transition-metal catalysis 2110 2116 7 10/31/23 20231127 NES 231127 Graph 1 Introduction Control of selectivity, in its various forms (chemo, regio, stereo, enantio, etc.) is a key requirement for modern organic synthesis. [Extracted from the article]

(E)- N -(2-Cyclohexyl-1-phenyl-3-(trimethylsilyl)allyl)aniline (19) General procedure A was used to react I N i -benzylaniline (183 mg, 1.0 mmol) with (cyclohexylethynyl)trimethylsilane (180 mg, 1.0 mmol) in the presence of catalyst B II-Bu b (111 mg, 0.1 mmol) for 24 h at 140 °C. Keywords: alkynes; allylamines; C-H activation; hydroaminoalkyl-ation; titanium; catalysis EN alkynes allylamines C-H activation hydroaminoalkyl-ation titanium catalysis 3759 3776 18 11/01/23 20231116 NES 231116 Graph The catalytic hydroaminoalkylation of alkenes [1][8] (Scheme 1), which takes place by a 100% atom-economical addition of the -C-H bond of a primary, [8] secondary, [8][8][8][8] or tertiary [8][8] amine across the alkene double bond, has received considerable attention over the past 15 years. N -(3,3-Dimethyl-2-methylenebutyl)aniline (1) 4d General procedure A was used to react I N i -methylaniline (107 mg, 1.0 mmol) with I tert i -butylacetylene (99 mg, 1.2 mmol) in the presence of catalyst B II-DIPP b (194 mg, 0.1 mmol) for 24 h at 140 °C. 3-Chloro- N -(3,3-dimethyl-2-methylenebutyl)aniline (5) General procedure A was used to react 3-chloro- I N i -methylaniline (142 mg, 1.0 mmol) with I tert i -butylacetylene (99 mg, 1.2 mmol) in the presence of catalyst B II-DIPP b (194 mg, 0.1 mmol) for 24 h at 140 °C. N -(3,3-Dimethyl-2-methylenebutyl)-4-(trifluoromethoxy)aniline (7) General procedure A was used to react I N i -methyl-4-(trifluoromethoxy)aniline (191 mg, 1.0 mmol) with I tert i -butylacetylene (99 mg, 1.2 mmol) in the presence of catalyst B II-DIPP b (194 mg, 0.1 mmol) for 24 h at 140 °C. [Extracted from the article]

Rh-Catalyzed Alkylation and Alkynylation of 1 with -Diazo- -keto Esters, -Diazo Esters, -D... In general, all reactions were carried out employing 50 mg of B 1 b . Rh catalysis, C-H activation, cross dehydrogenative coupling, GBT-440, diazo ester, TIPS-EBX In the context of developing new analogues of the GBT-440, one of our initial objectives was replacing the hydroxymethyl ether (which connects the pyridine and salicylaldehyde cores) with an olefin or a keto ester by pyrazole-directed C-H activation on the pyridine ring (Scheme 1, eq. 1). Keywords: Rh catalysis; C-H activation; cross dehydrogenative coupling; GBT-440; diazo ester; TIPS-EBX EN Rh catalysis C-H activation cross dehydrogenative coupling GBT-440 diazo ester TIPS-EBX 3600 3609 10 10/19/23 20231102 NES 231102 Graph Heterocyclic scaffolds like pyridine and pyrazole are the most privileged scaffolds present in many drug molecules. [Extracted from the article]

SP 1 sp H NMR (400 MHz, CDCl SB 3 sb ): = 12.46 (s, 1 H), 9.12-9.10 (m, 2 H), 8.84 (dd, I J i SB 1 sb = 4.2, I J i SB 2 sb = 1.7 Hz, 1 H), 8.14-8.10 (m, 2 H), 7.62-7.58 (m, 1 H), 7.49 (dd, I J i SB 1 sb = 8.2, I J i SB 2 sb = 1.1 Hz, 1 H), 7.42-7.39 (m, 2 H), 7.32 (d, I J i = 8.1 Hz, 1 H), 7.28-7.24 (m, 1 H), 6.83 (s, 1 H), 4.29-4.23 (m, 5 H), 1.43 (t, I J i = 7.3 Hz, 3 H). SP 1 sp H NMR (400 MHz, CDCl SB 3 sb ): = 7.98 (d, I J i = 7.7 Hz, 1 H), 7.94 (dd, I J i SB 1 sb = 8.0, I J i SB 2 sb = 0.9 Hz, 1 H), 7.40-7.36 (m, 1 H), 7.33 (d, I J i = 7.8 Hz, 1 H), 7.21-7.17 (m, 1 H), 6.84-6.82 (m, 2 H), 4.27 (q, I J i = 7.2 Hz, 2 H), 3.91 (s, 3 H), 1.39 (t, I J i = 7.2 Hz, 3 H). SP 1 sp H NMR (400 MHz, CDCl SB 3 sb ): = 8.64 (s, 1 H), 8.03 (d, I J i = 7.7 Hz, 1 H), 7.41-7.37 (m, 1 H), 7.32 (d, I J i = 8.1 Hz, 1 H), 7.19-7.16 (m, 1 H), 7.12 (s, 1 H), 4.34 (q, I J i = 7.2 Hz, 2 H), 4.28 (q, I J i = 7.2 Hz, 2 H), 3.10 (t, I J i = 8.0 Hz, 2 H), 1.65-1.57 (m, 2 H), 1.40-1.35 (m, 8 H), 1.28-1.19 (m, 16 H), 0.79 (t, I J i = 6.5 Hz, 3 H). SP 1 sp H NMR (400 MHz, CDCl SB 3 sb ): = 8.70 (s, 1 H), 8.11 (d, I J i = 7.7 Hz, 1 H), 7.96-7.96 (m, 1 H), 7.93-7.90 (m, 1 H), 7.56-7.53 (m, 1 H), 7.49-7.43 (m, 2 H), 7.39 (d, I J i = 8.2 Hz, 1 H), 7.27-7.22 (m, 2 H), 4.32 (q, I J i = 7.3 Hz, 2 H), 4.08 (q, I J i = 7.2 Hz, 2 H), 2.58 (s, 3 H), 1.38 (t, I J i = 7.2 Hz, 3 H), 1.00 (t, I J i = 7.1 Hz, 3 H). [Extracted from the article]

Keywords: manganese; nickel; palladium; bimetallic catalysis; indole; oxidation; C-H activation EN manganese nickel palladium bimetallic catalysis indole oxidation C-H activation 3625 3631 7 10/19/23 20231102 NES 231102 Graph I N i -Heterocyclic scaffolds are crucial in synthetic and medicinal chemistry. Subsequently, imine formation and C-H activation reaction were carried out and indole B 5a b was isolated in 19% total yield (76% yield was obtained in the C-H activation step). The filtration step seems to be crucial for the Pd-catalyzed C-H activation reaction, indicating that the presence of the Ni catalyst to a great extent inhibited the Pd-catalyzed reaction leading to a poor overall yield of the indole B 5a b . In the case of I m i -(trifluoromethyl)aniline ( B 3c b ), its corresponding imine B 4c b underwent cyclization at the less-hindered position affording 6-substituted indole B 5c b in 34% yield (yield from last step). [Extracted from the article]

Axially chiral N-arylindoles bearing a stereogenic C-N axis are unique important scaffolds in natural products, advance materials, pharmaceuticals and privileged chiral ligands or catalysts. Herein, we report the direct synthesis of C-N axially chiral N-arylindoles through a Pd-catalyzed free amine-directed atroposelective C-H olefination enabled by a spiro phosphoric acid (SPA) ligand. A wide range of enantioenriched N-aromatic amine indoles were obtained in high yields with good enantioselectivities (35 examples, up to 91% yield and up to 96% ee). The chiral products with free amine group offer an effective functional handle for down-stream diversity-oriented synthesis. [ABSTRACT FROM AUTHOR]

The activation of C-H bonds is a potent tool for modifying molecular structures in chemistry. This article details the steps involved in a novel ligand bearing a bicyclic [3.3.1]-nonane framework and bissulfoxide moiety. A palladium catalyzed allylic C-H oxidation method enables a direct benzyl-allylic functionalization with the bissulfoxide ligand. Bissulfoixde ligand possesses a rapidly constructed bicyclic [3.3.1] framework and it proved to be effective for enabling both N- and C-alkylation. A total of 13 C-H activation productions were reported with good to excellent yields. This report validated that it is necessary to include bissulfoxide as a ligand for superior reactivities. Naftifine was produced utilizing developed C-H functionalization methodology in good overall yields.

Disclosed herein is a novel Rh/Ag co-catalyzed SNH directed C–H activation and C–H/N–H bond functionalization protocol of free NH-sulfoximines with hypervalent iodonium ylides. With the aid of AgOTf, these C–H functionalization/cyclization sequences could be achieved at room temperature conditions. The reaction employed EtOH as a “green” solvent and low catalyst loading was required under an oxygen/water-insensitive condition. Under this mild protocol, a wide range of polyheterocyclic sulfoximines bearing fused saturated carbo(hetero)cycles are readily prepared, even toward a complex pharmaceutical Folliculin analog.

The C3-functionalization of furfural using homogeneous ruthenium catalysts requires the preinstallation of an ortho-directing imine group, as well as high temperatures, which did not allow scaling up, at least under batch conditions. In order to design a safer process, we set out to develop a continuous flow process specifically for the C3-alkylation of furfural (Murai reaction). The transposition of a batch process to a continuous flow process is often costly in terms of time and reagents. Therefore, we chose to proceed in two steps: the reaction conditions were first optimized using a laboratory-built pulsed-flow system to save reagents. The optimized conditions in this pulsed-flow mode were then successfully transferred to a continuous flow reactor. In addition, the versatility of this continuous flow device allowed both steps of the reaction to be carried out, namely the formation of the imine directing group and the C3-functionalization with some vinylsilanes and norbonene.

Catalytic methods for the direct introduction of hydrogen isotopes into organic molecules are essential to the development of improved pharmaceuticals and to the alteration of their absorption, distribution, metabolism, and excretion (ADME) properties. However, the development of homogeneous catalysts for selective incorporation of isotopes in the absence of directing groups under practical conditions remains a long-standing challenge. Here, we show that a phosphine-ligated, silver-carbonate complex catalyzes the site-selective deuteration of C-H bonds in five-membered aromatic heterocycles and active pharmaceutical ingredients that have been resistant to catalytic H/D exchange. The reactions occur with CH3OD as a low-cost source of the isotope. The silver catalysts react with five-membered heteroarenes lacking directing groups, tolerate a wide range of functional groups, and react in both polar and nonpolar solvents. Mechanistic experiments, including deuterium kinetic isotope effects, determination of kinetic orders, and identification of the catalyst resting state, support C-H bond cleavage from a phosphine-ligated, silver-carbonate intermediate as the rate-determining step of the catalytic cycle.

The direct, catalytic arylation of simple arenes in small excess with aryl bromides is disclosed. The developed method does not require the assistance of directing groups and relies on a synergistic catalytic cycle in which phosphine-ligated silver complexes cleave the aryl C-H bond, while palladium catalysts enable the formation of the biaryl products. Mechanistic experiments, including kinetic isotope effects, competition experiments, and hydrogen-deuterium exchange, support a catalytic cycle in which cleavage of the C-H bond by silver is the rate-determining step.

[Display omitted] An efficient procedure for the preparation of furo[2,3- c ]-quinolin-4(5 H)-ones from 2-furoic acid N -(o -bromoaryl)- amides via selective intramolecular C(3)–H arylation of the furan nucleus involves the catalysis by a Pd/NHC system generated in situ from Pd(OAc) 2 and readily available IPrSPh HCl proligand. A series of novel furo[2,3- c ]quinolin-4(5 H)-ones were prepared in 65–80% isolated yields. [ABSTRACT FROM AUTHOR]

Transition-metal-catalyzed allenes-involved C–H functionalizations demonstrate unique selectivity and undergo exceptional pathways due to the existence of elusive orthogonal cumulative CCC bonds. As a result, it allows for a diverse array of C–H activation reactions, such as allylation, alkenylation, allenylation, dienylation, propargylation, and annulation. In this review, we comprehensively summarize the noteworthy aspects of transition-metal-catalyzed C–H functionalizations involving variously substituted allenes.

Mn-catalysed C–H activation has emerged as a useful sustainable methodology for the formation of new C–C bonds. To date most of the protocols are described in organic solvents. Water as solvent, on the other hand, would be highly advantageous, but is often incompatible with organometallic chemistry. Herein, we describe the C–H activation of indoles using an unmodified, commercially available manganese catalyst in water. Two types of valuable allyl groups can be added and a good substrate scope is described. Substitution at the C-3 group is tolerated, allowing access to medicinally important frameworks, and the reaction works on a gram scale. Finally, harnessing the tolerance of water as the reaction medium, D2O can be used as an inexpensive source of deuterium for the C-2 labelling of indoles.

SP 1 sp H NMR (400 MHz, CDCl SB 3 sb ): = 9.02 (s, 1 H), 8.42 (d, I J i = 7.6 Hz, 1 H), 8.14-8.10 (m, 2 H), 7.95-7.86 (m, 3 H), 7.69-7.56 (m, 3 H). SP 1 sp H NMR (400 MHz, CDCl SB 3 sb ): = 8.29 (t, I J i = 8.8 Hz, 2 H), 7.67 (s, 1 H), 7.53 (s, 1 H), 7.36 (t, I J i = 8.0 Hz, 2 H), 2.56 (s, 6 H). Keywords: C-H activation; quinazoline; heterocycle; sulfur; benzisothiazoloquinazolinone EN C-H activation quinazoline heterocycle sulfur benzisothiazoloquinazolinone 3364 3372 9 09/29/23 20231018 NES 231018 Graph Sulfur-containing compounds represent over 20% of FDA-approved drugs. SP 1 sp H NMR (400 MHz, CDCl SB 3 sb ): = 8.39 (d, I J i = 7.2 Hz, 1 H), 8.10 (d, I J i = 7.2 Hz, 1 H), 7.87 (s, 2 H), 7.70 (s, 1 H), 7.56-7.47 (m, 2 H). [Extracted from the article]

Selective dehydrogenative silylation is one of the most valuable tools for synthesizing organosilicon compounds. In this study, a regio- and stereoselective ruthenium-catalyzed dehydrogenative intermolecular silylation was firstly developed to access (E)-alkenyl silyl-ether derivatives and silyl-ether heterocycles with good functional group tolerance. Furthermore, two pathways for RuH2(CO)(PPh3)3/NBE-catalyzed dehydrogenative intermolecular silylation of alcohols and alkenes as well as intermolecular silylation of naphthol derivatives were investigated with H2SiEt2 as the hydrosilane reagent. [ABSTRACT FROM AUTHOR]

Herein, we report a rhodium-catalyzed intramolecular acylation of 2-(indol-1-yl)benzoic acids under redox-neutral reaction conditions (Scheme 1c). Rhodium, redox-neutral conditions, intramolecular acylation, C-H activation, indoloindolones Keywords: rhodium; intramolecular acylation; redox-neutral conditions; indoloindolones; C-H activation EN rhodium intramolecular acylation redox-neutral conditions indoloindolones C-H activation 1894 1898 5 09/15/23 20231004 NES 231004 Graph Indole and indolone scaffolds are ubiquitous building blocks found in many biologically active compounds; hence, fusing these two heteroaromatic cores allows the introduction of new drug-like molecules in pharmaceutical sciences. [24] The control experiments indicated that both [RhCl(CO) SB 2 sb ] SB 2 sb and Piv SB 2 sb O were essential for promoting the intramolecular acylation reaction (entries 17 and 18). [Extracted from the article]

2-Propargyl-1,3-dicarbonyl compounds have been carbonylated under oxidative conditions and with the catalysis of the PdI2/KI catalytic system to selectively afford previously unreported 2-(4-acylfuran-2-yl)acetamides in fair to good yields (54–81%) over 19 examples. The process takes place under relatively mild conditions and occurs via a mechanistic pathway involving Csp-H activation by oxidative monoamincarbonylation of the terminal triple bond of the substrates with formation of 2-ynamide intermediates, followed by 5-exo-dig O-cyclization (via intramolecular conjugate addition of the in situ formed enolate to the 2-ynamide moiety) and aromative isomerization. [ABSTRACT FROM AUTHOR]

Environmentally sustainable and selective conversion of methane to valuable chemicals under ambient conditions is pivotal for the development of next-generation photocatalytic technology. However, the lack of microscopic knowledge on its reaction mechanism prevents the development of engineering strategies for methane photocatalysis. Here we introduce key molecular-level insights into the photocatalytic green utilization of methane. Activation of the robust C–H bond of methane is hardly induced by the direct interaction with photogenerated holes trapped at the surface of photocatalyst ; instead, the C–H activation is significantly promoted by the photoactivated interfacial water species. The interfacial water hydrates and properly stabilizes hydrocarbon radical intermediates, thereby suppressing their overstabilization. Owing to these water-assisted effects, the photocatalytic conversion rates of methane under wet conditions are dramatically improved by typically more than 30 times at ambient temperatures (～300 K) and pressures (～1 atm) in comparison to those under dry conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Various Lewis acids catalyse the electrophilic amidation of arenes in acetic acid. • O-acetyl acetohydroxamic is used as atom-efficient amidating agent. • Kinetic and spectroscopic data point towards electrophilic aromatic substitution. Electrophilic arene C H amination constitutes an intrinsically more atom- and step-economical pathway towards arylamines than C X → C N methods. However, most literature examples are restricted to arenes with extensive directing groups (DG) and/or nitrogen coupling partners with large leaving groups (LG). Moreover, only few cases of EAs using cheap metals (e.g. , Fe) have been reported. Herein, we demonstrate the catalytic activity of various Lewis acids in the electrophilic amidation of simple arenes with O -acetyl acetohydroxamic acid in acetic acid. With 5 mol% FeIII(citrate)·H 2 O, up to 27 % yield was achieved, whereas 5 mol% BiCl 3 gave up to 31 % yield. Instability of the amidation agent and product inhibition were identified as the yield-limiting factors. The observed regioselectivity, as well as kinetic and spectroscopic data suggest an electrophilic aromatic substitution mechanism, in which acetic acid and the Lewis acid generate a highly electrophilic species from AcNHOAc. [ABSTRACT FROM AUTHOR]

[Display omitted] • Late-stage C(sp3)–H oxyfunctionalization of saturated 5 α - and 5 β -steroids with gonane core. • Synthetic access to 20 oxidized metabolites, using H 2 O 2 as oxidant. • Preferential C–H hydroxylation of methylenic groups. • The oxidation regioselectivity is governed by steric effects. Herewith we report late-stage catalytic selective oxidative functionalization of several steroids with a common gonane core, namely androstane derivatives 5 α -androsterone-3-acetate, 5 β -androstan-17 β -ol-3-one (etiocholan-17 β -ol-3-one), 17 β -acetoxy-5 β -androstan-3-one, and 5 β -pregnane-3,20-dione, at C–H groups in the presence of chiral bis -amino- bis -pyridylmethyl and structurally related Mn complexes, using H 2 O 2 as terminal oxidant. Depending on the steric demand and absolute chirality of the catalyst, mono-hydroxylation at A, B, or C rings is achieved in up to 58% isolated yield. Strongly hydrogen-bond donating solvent hexafluoroisopropanol (HFIP) effectively protects the C17–OH group in etiocholan-17 β -ol-3-one from ketonization, thus providing an opportunity to obtain 6,17- and 12,17-dihydroxy androstane derivatives without using protecting groups. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Enantioselective or enantioconvergent iron‐catalyzed ring‐closing C(sp3)‐H aminations of N‐aroyloxyurea through intermediate iron nitrene species provide chiral 2‐imidazolidinones in up to 99% yield and with up to 95% ee (40 examples). This is a rare example in which sustainable iron catalysis is combined with C(sp3)‐H amination and asymmetric catalysis. Chiral 2‐imidazolidinones are prevalent structural motifs in bioactive molecules and can also be hydrolyzed to valuable chiral vicinal diamines in a single step. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: We herein report a simple ether‐directed iridium‐catalyzed site‐ and enantioselective C(sp2)‐H borylation of benzhydryl ethers for the first time. Various chiral benzhydryl ethers were obtained with high enantioselectivities in the presence of a tailor‐made chiral bidentate boryl ligand. We found that the kinetic resolution relay significantly amplified the enantioselectivity. The synthetic utility of the current method was demonstrated by gram‐scale C—H borylation and C—B bond transformations. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Benzothiadiazine‐1,1‐dioxide scaffold is bioactive framework with wild utility and applications. Synthesis of benzothiadiazine‐fused isoquinoline derivatives and spiro benzothiadiazine derivatives through transition metal‐catalyzed C—H activation/annulation was reported. 3‐Phenyl‐2H‐benzothiadiazine‐1,1‐dioxide was used as the reaction substrate, and vinylene carbonate and 4‐diazopyrazolone were used as the coupling reagents, respectively. This strategy provides straightforward access to complex N‐heterocycles in a highly efficient and simple manner. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Isochromanone is the core structure of many bioactive compounds. Direct oxidation of isochromans is one of leading methods for the construction of isochromanones, while most established processes remain suffering from the use of environmentally unfriendly metal oxidants, harsh reaction conditions, and the difficulty in catalyst recycling and product separation. Herein, we report a convenient, cost‐effective, and green method for the synthesis of high‐value added isochromanones via isochroman oxidations with O2 by a novel heterogeneous vanadium cluster catalyst (Cat.1) under mild conditions. This reaction protocol demonstrates high catalytic activity with good catalyst recyclability and reusability for a wide scope of substrates. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Herein, we have developed a strategy of Rh(III)‐catalyzed C—H activation of N‐nitrosoanilines and iodonium ylides to construct novel tetralydrocarbzol‐4‐one scaffolds, which provided valuable templates for sequential C—H functionalization such as alkylation, alkenylation, amidation and (hetero)arylation at C5‐position of tetralydrocarbzol‐4‐one with different coupling partners. Gram‐scale synthesis and further transformations of tetralydrocarbzol‐4‐one derivatives to Ondansetron and its analogues demonstrated the utility of this protocol, which enabled the concise and diverse construction of biologically active molecules. [ABSTRACT FROM AUTHOR]

A novel method for the preparation of diazenes organic molecules that utilized an inexpensive copper catalyst has been developed. The catalytic system shows excellent functional-group tolerance with aryldiazonium salts and unactivated cycloalkane in the absence of oxidant, enabling facile synthesis of various useful alkylarylazo compounds with good yields. In addition, indoles can be synthesized in a one-pot manner. [Display omitted] • A novel method for the preparation of diazenes organic molecules with inexpensive copper catalyst. • Using aryldiazonium salts and unactivated cycloalkane as substrates without oxidant. • Alkylarylazo compounds were produced with good yields with excellent functional-group tolerance. • Indoles can be synthesized in a one-pot manner. Diazenes are of particular importance in organic synthesis and routinely utilized as dyes, photoswitches, indicators, radical reaction initiators, food additives, and pharmaceuticals. In this work, a novel copper-catalyzed direct carbodiazenylation of cycloalkanes with aryldiazonium salts toward the synthesize of alkylarylazo compounds has been developed. The reaction can be carried out under redox neutral conditions which allow the use of highly functionalized substrates and a wide range of diazenes were produced in moderate to good yields. Notably, this process operates under mild conditions and then enables the preparation of indoles straightforwardly. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Pd‐catalyzed asymmetric allylic C—H functionalization has emerged as a powerful tool to access chiral, densely functionalized molecules from easily accessible alkenes, enabling the increase of the step‐ or atom‐economy by minimizing functional group manipulations for preparing allylating reagents. Due to the inadequacy of stereoselection strategies, the asymmetric allylic C—H functionalization is still in the early stage. In this essay, we will describe our journey to identification of asymmetric catalytic systems, mechanism of allylic C—H activation, control of stereo‐ and regioselectivity, and applications in asymmetric synthesis. What is the most favorite and original chemistry developed in your research group? The establishment of asymmetric organo/transition‐metal cooperative catalysis to enable enantioselective reactions. How do you get into this specific field? Could you please share some experiences with our readers? We initially attempted to expand the chiral enamine/Pd cooperative catalysis to create asymmetric allylic C—H alkylation of α‐olefins. Although this idea turned out to be unsuccessful, we finally accomplished an asymmetric allylic C—H alkylation of allylarenes enabled by cooperative catalysis of achiral amine, chiral phosphoric acid and palladium, marking a starting point to deeply get involved in this field. How do you supervise your students? I am basically strict with students in regulation and technique, but respect them very much. They are always my co‐workers and have equal authority in chemistry if they like. What is the most important personality for scientific research? Hardworking and critical thinking always pay off. What are your hobbies? What's your favorite book(s)? I have ever enjoyed learning martial arts and playing basketball, but now enjoy reading history books. Who influences you mostly in your life? So many people influence me so much in my life, it's really hard to say who mostly does. I heard the story of Hua Loo‐Keng (Hua Luo‐Geng), an eminent mathematician, in my childhood and his legend always motivates me to keep working hard. What is your favorite journal(s)? So many journals I keep reading every day, if I have to say, J. Am. Chem. Soc. may be my favorite, because it publishes, so far, my most representative work. Of course, Chin. J. Chem. is among the favorite journals. Could you please give us some advices on improving Chinese Journal of Chemistry? Keep disseminating the journal in international community and improve the diversity in authorship and contents to make it really international. [ABSTRACT FROM AUTHOR]

By exploiting the combined use of a heterogeneous recyclable palladium(II)-bis(N-heterocyclic carbene) catalyst and cyclopentyl methyl ether (CPME) as a convenient recoverable safer reaction medium, an effective wasteminimized approach has been developed for the intramolecular Pd-catalyzed C(sp3)-H activation of methyl pyrrole derivatives. This synthetic tools has allowed to access condensed N-heterocycles generally endowed with biological activities and representatively are the core motif of complex molecules such as Mitomycines and Tylophorines. The heterogeneous catalytic system could be recovered and reused up to representative five runs without any loss in efficiency. The target products (19 examples) have been obtained selectively and with excellent isolated yields up to 93%. The approach leads to the definition of a protocol with a very good E-factor (21) which is much lower (up to 98%) than those of comparable literature examples. Other green metrics have been calculated and the data collected demonstrate that our newly developed protocol is very promising in terms of its environmental impact profile. [ABSTRACT FROM AUTHOR]

A simple and efficient nitrile-directed meta-C-H olefination, acetoxylation, and iodination of biaryl compounds is reported. Compared to the previous approach of installing a complex U-shaped template to achieve a molecular U-turn and assemble the large-sized cyclophane transition state for the remote C-H activation, a synthetically useful phenyl nitrile functional group could also direct remote meta-C-H activation. This reaction provides a useful method for the modification of biaryl compounds because the nitrile group can be readily converted to amines, acids, amides, or other heterocycles. Notably, the remote meta-selectivity of biphenylnitriles could not be expected from previous results with a macrocyclophane nitrile template. DFT computational studies show that a ligand-containing Pd-Ag heterodimeric transition state (TS) favors the desired remote meta-selectivity. Control experiments demonstrate the directing effect of the nitrile group and exclude the possibility of non-directed meta-C-H activation. Substituted 2-pyridone ligands were found to be key in assisting the cleavage of the meta-C-H bond in the concerted metalation-deprotonation (CMD) process.

Herein, we report an unprecedented Rh(III)-catalyzed C–H activation/annulation cascade of readily available enaminones with iodonium ylides towards the convenient synthesis of isocoumarins. This coupling system proceeds in useful chemical yields (up to 93%) via a cascade C–H activation, Rh-carbenoid migratory insertion and acid-promoted intramolecular annulation. The success of gram-scale reaction and diverse functionalization of isocoumarins demonstrated the synthetic utility of this protocol.