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The C–H borylation strategy has spurred intense research endeavors due to the high atom- and step-economy it represents and because of the broad range of utilities of the resulting organoboranes. Nevertheless, this powerful transformation has had limited substrate scope and poor regioselectivity when it was applied to Lewis basic substrates (e.g., azines). The basic functionalities in substrates can coordinate to the metal centers, hindering the formation of products. Herein, we provide a brief overview of recent advances in transition-metal-­catalyzed regioselective C–H borylation of pyridines. Attention is paid to the latest contributions, which have demonstrated remarkable ­regioselectivity.1 Introduction2 para-Selective C−H Borylation3 meta-Selective C−H Borylation4 ortho-Selective C−H Borylation5 Summary

We report an efficient additive- and solvent-free O-alkylation of P(O)–OH compounds with epichlorohydrocarbons for the synthesis of epoxy-group-containing phosphinates. The transformation proceeds through a tandem reaction involving ring-opening and annulation processes. The ring-opened products and dechlorinated products can be obtained selectively by controlling the reaction conditions. This protocol is expected to be useful in industry because it is readily scaled up to a gram level and involves simple posttreatment.

A one-pot, three-component difunctionalization of quinones with indoles and arylamines has been developed to synthesize indole functionalized p-iminoquinones derivatives. The approach employed AgOAc as the catalyst in the presence of 3-chlorophenylboronic acid, giving a series of indole functionalized p-iminoquinones derivatives in moderate to good yields. This catalytic approach represents a step-economic and convenient strategy for the difunctionalization of quinones. A plausible reaction pathway has been proposed based on a series of control experiments.

Over the past decade, the incidence of sulfoximine functional groups in pharmaceuticals and agrochemicals has increased significantly. This increase has led to a range of useful strategies for installing a S(VI) functionality into complex organic molecules. Conventional synthetic methods for forming α-substituted sulfonimidoyl motifs rely on late-stage modifications at sulfur and involve multistep routes. We report the development of an efficient and general method for the synthesis of various α-arylated sulfoximines through a selective S-alkylation. This strategy uses economical and readily available β-sulfoximine esters as precursors of sulfinamides and has been demonstrated by the preparation of 31 sulfoximines in good yields (up to 87%).

A Ph3P/ICH2CH2I-promoted dehydroxylative cyanation of alcohols has been developed. In contrast to previous dehydroxylative cyanation methods that can suffer from several limitations, such as the use of transition metals or moisture-sensitive Lewis acids, this protocol features convenient operations, mild reaction conditions, and the use of cheap and widely available reagents.

A robust Pd(0)-catalyzed decarboxylation alkylation has been developed to construct quaternary stereocenters through the use of chiral tert-butanesulfinamide as the directing group. This strategy provides a simple and efficient route to the construction of quaternary chiral centers at the α-position of chiral sulfinamides, with high diastereoselectivities and high yields.

An atom-economical and environmentally benign approach for the synthesis of 3-indolylquinones was achieved successfully via direct oxidative C–C coupling of quinones/hydroquinones with indoles using (NH4)2S2O8 in dichloroethane at 80 °C. The efficiency of this catalytic approach was established by a broad scope of substrates involving quinones and hydroquinones to give high yields (61–93%) of 3-indolylquinones. The present protocol is simple, practical, and show good functional group tolerance. In addition, the obtained 3-indolylnaphthoquinones were conducted to further transformation to synthesize 2-amino-3-indolylnaphthoquinone and polycyclic N-heterocycles, respectively.

During the past two decades, gold-catalyzed nitrene-transfer reactions via α-imino gold carbenes have received extensive attention, as this strategy provides rapid access to nitrogen-containing molecules with high efficiency. In this review, we focus on recent progress in gold-catalyzed formal annulations of ynamides with isoxazole derivatives as nitrene-transfer reagents via α-imino gold carbenes in atom-economic and rapid construction of N-heterocycles.

Conjugated dienes underwent Ni-catalyst-promoted 1,2-hydrocarboxylation in a 1:1 ratio with carbon dioxide under atmospheric pressure in the presence of diisobutylaluminum hydride (DIBAL-H) to give the corresponding β,γ-unsaturated carboxylic acids, without dimerization or oligomerization of the conjugated diene.

Organophosphines are an important class of ligands widely used in organic chemistry. Although great progress has recently been made in the rapid construction of new phosphines through Rh- or Ru-catalyzed C–H bond functionalizations, synthetic access to more diverse phosphines remains a challenge. We describe an efficient process for the rhodium-catalyzed phosphorus(III)-directed hydroarylation of internal alkynes to generate various alkenylated and 2′,6′-dialkenylated biarylphosphines with high selectivity. A range of diverse alkynes and phosphines were effectively prepared with broad functional-group compatibility under the optimized conditions. In addition, the developed protocol can be extended to modify chiral phosphine ligands, providing enantioenriched alkenylated phosphines without erosion of the enantiomeric excess.

Description of molecular stereostructure is critical for the machine learning prediction of asymmetric catalysis. Herein we report a spherical projection descriptor of molecular stereostructure (SPMS), which allows precise representation of the molecular van der Waals (vdW) surface. The key features of SPMS descriptor are presented using the examples of chiral phosphoric acid, and the machine learning application is demonstrated in Denmark’s dataset of asymmetric thiol addition to N-acylimines. In addition, SPMS descriptor also offers a color-coded diagram that provides straightforward chemical interpretation of the steric environment.

Alkylated heteroarenes are widely found in bioactive molecules and pharmaceuticals. Therefore, there is great interest in developing a chemoselective alkylation of heteroarenes under mild conditions, particularly during a late-stage functionalization step for the purpose of rapid derivatization. Herein, we introduce an efficient visible-light-promoted C–H alkylation of nitrogen-containing heteroarenes by using C4-alkyl 1,4-dihydropyridines (DHPs) as radical precursors at ambient temperatures. A broad scope of heteroarenes, such as 4-hydroxyquinazoline and its derivatives, including those bearing electron-donating or electron-withdrawing groups, can be successfully alkylated in good yields by using various C4-alkyl DHPs.

α,α-Dideuterio benzyl alcohols are important building blocks for the synthesis of deuterium-labeled medicines and agrochemicals. We have developed the first general single-electron transfer reductive deuteration of readily commercially available aromatic esters for the synthesis of α,α-dideuterio benzyl alcohols using benign D2O and a mild single-electron donor SmI2. This operationally convenient method features very good functional group tolerance and high deuterium incorporations (>95% D2). The potential impact has been exemplified by the synthesis of numerous deuterium labeled building blocks of important bioactive compounds. Most crucially, the method represents the first example of selective reductive deuteration of benzylic-type ketyl radicals using mild and highly chemoselective lanthanide(II) reagents.

An efficient and simple Cu-catalyzed Reformatsky reaction of ketones and aldehydes has been accomplished with ethyl iodoacetate. Excellent yields of β-hydroxyl esters were achieved with a range of ketones and aldehydes, which varied from aromatic to aliphatic, unsaturated to saturated ketones and aldehydes. This practical and convenient transformation was conducted with inexpensive, readily available, and commercial starting materials under mild reaction conditions.

An iodine-catalyzed [3+2]-cycloaddition reaction of substituted benzylidenemalononitriles and ethyl glycinate hydrochloride in DMF has been developed for the synthesis of 5-amino-1H-pyrrole-2-carboxylates. This efficient method provides access to a variety of structurally diverse pyrrole-2-carboxylate derivatives. The structure of a typical product was confirmed by X-ray crystallography.

An intramolecular oxetane ring-opening was developed, affording novel 2-(hydroxymethyl)-2,3-dihydroimidazo[1,2-c]quinazolines from N-(3-methyloxetan-3-yl)quinazolin-4-amines under mild conditions. The resulting medicinally relevant tricyclic scaffolds were synthesised in good yields with diverse substituents. Moreover, reaction optimisation led to the development of a one-pot procedure.

This paper describes an efficient method for constructing cyclic β-amino acids bearing quaternary stereocenters. NaHMDS-promoted asymmetric α-alkylation was employed to obtain the key intermediates with quaternary stereogenic centers, which were subsequently reduced by NaBH4 in 10% methanol in THF, with high yields and high diastereoselectivities. By removing the allyl ester group and the chiral auxiliary, the corresponding cyclic β-amino acid hydrochlorides were finally obtained.

A practical iodine-catalyzed oxidative functionalization of isoquinolines with methylarenes is developed, which can be triggered by the selected oxidants to produce C1- or N-benzyl-substituted products selectively. This method utilizes readily available isoquinolines and methylarenes as starting materials and proceeds under metal-free conditions with broad substrate scope with respect to methylarenes, avoiding the usage of expensive metal catalysts and generation of halide and metal wastes.

Methods for the synthesis of amides via the direct oxidation of imines are rarely reported. Here we report an efficient method for Pd-catalyzed oxidation of imines to amide derivatives by the use of cheap aqueous tert-butyl hydroperoxide as an oxidant through a Wacker-type reaction. This method is practically convenient and displays high functional group tolerance, allowing a variety of imines to transform into the corresponding amide derivatives in moderate to good yields.

The enantioselective incorporation of alkyl groups in thiochromones was realized for the first time by a Cu/(R,S)-PPF-P t Bu2-catalyzed conjugate addition of Grignard reagents to thiochromones. With this method, a series of 2-methylthiochromanones were obtained in good yields (up to 96% yield) with moderate-to-good ee values (up to 87% ee). The established method expedites the synthesis of a large library of chiral thiochromanones for further synthetic applications and biological studies.

The direct anti-Markovnikov addition of alcohols to styrene derivatives represents a streamlined route to β-phenethyl ethers, a substructure frequently found in pharmaceuticals and other bioactive ­molecules. Here, we discuss how the development of such a reaction can complement and address limitations of current methods for β-phenethyl ether synthesis. In particular, we highlight our recent ­approach toward achieving this challenging alcohol addition reaction through P4-t-Bu superbase catalysis. A summary of compatible aryl alkenes and alcohols is provided to inform readers of potential applications of this new catalytic transformation, as well as its current limitations and future directions.1 Introduction2 Anti-Markovnikov Alcohol Addition to Aryl Alkenes: Background3 Superbase-Catalyzed Alcohol Addition to Aryl Alkenes4 Summary and Outlook

A convenient method was developed for direct regioselective fluorination of 8-aminoquinolines at the C-5 position by copper-catalyzed remote C–H activation using Selectfluor as the electrophile fluorinating reagent. With this method, diverse fluorinated quinoline derivatives were facilely obtained under mild conditions with moderate yields.

A simple and efficient selective diacetoxylation of 1,4-disubstituted 1,2,3-triazoles by Pd-catalyzed C–H bond activation is described. PhI(OAc)2 was used as an acetyloxy source to convert aromatic sp2 C–H bonds into C–O bonds with high selectivity by employing a 1,2,3-triazole ring as an elegant directing group. A range of 1,2,3-triazoles bearing two acetyloxy groups can be readily synthesized by the reaction.

A triphenylphosphine-promoted [3+2] cycloaddition of α,γ-bis-substituted allenoates and N-tosylaldimines followed by alkene isomerization was disclosed, affording a series of functionalized 2-pyrroline derivatives in moderate chemical yields with random diastereoselectivities.

The combination of a Pd catalyst and tert-butyl hydro­peroxide (TBHP) is a powerful catalytic system for many types of oxidative transformations. Here, we report that a Pd/TBHP system facilitates the oxidation of indoles with a range of functionalities to give the corresponding isatin derivatives in good yields.

Nickel catalyzes the multicomponent coupling reaction of terminal alkenes, carbon dioxide, and organoaluminum reagents, leading to the synthesis of homoallylic alcohols in moderate-to-good yields with excellent regio- and stereoselectivities.