A new class of chiral 2,2'-bipyridine ligands, SBpy, featuring minimized short-range steric hindrance and structural tunability was rationally designed and developed, and the effectiveness was demonstrated in the first highly enantioselective Ni-catalyzed addition of aryl halides to aldehydes. In comparison with known approaches using preformed aryl metallic reagents, this reaction is more step-economical and functional group tolerant. The reaction mechanism and a model of stereocontrol were proposed based on experimental and computational results.

Organocatalyzed asymmetric Friedel-Craft reactions have enabled the rapid construction of chiral molecules with highly enantioselectivity enriching the toolbox of chemists for producing complex substances. Here, we report N-heterocyclic carbene-catalyzed asymmetric indole Friedel-Crafts alkylation-annulation with α,β-unsaturated acyl azolium as the key intermediate, affording a large variety of indole-fused polycyclic alkaloids with excellent diastereo-and enantioselectivities. The reaction mechanism is also investigated, and the reaction products can be easily converted to highly functionalized indole frameworks with different core structures.

Catalyticc arbene-transfer reactions constitute a class of highly useful transformations in organic synthesis. Although catalysts based on ar ange of transition-metals have been reported, the readily accessible nickel(II)-based complexes have been rarely used. Herein, an air-stable nickel(II)-carborane complex is reported as aw ell-defined, versatile and recyclable catalyst for selectivec arbene transfer reactions with low catalyst loading under mild conditions. This catalysti se ffective for several types of reactions including diastereoselectivec yclopropanation, epoxidation, selective XÀHi nsertions (X = C, N, O, S, Si), particularly for the unprotected substrates. This represents ar are example of carborane ligands in base metal catalysis.

In contrast to previous approaches to chiral α‐aryl carboxylic acids that based on reactions using hazardous gases, pressurized setup and mostly noble metal catalysts, in this work, a nickel‐catalyzed general, efficient and highly enantioselective carboxylation reaction of racemic benzylic (pseudo)halides under mild conditions using atmospheric CO2 has been developed. A unique chiral 2,2′‐bipyridine ligand named Me‐SBpy featuring compact polycyclic skeleton enabled both high reactivity and stereoselectivity. The utility of this method has been demonstrated by synthesis of various chiral α‐aryl carboxylic acids (30 examples, up to 95 % yield and 99 : 1 er), including profen family anti‐inflammatory drugs and transformations using the acids as key intermediates. Based on mechanistic experimental results, a plausible catalytic cycle involving Ni‐complex/radical equilibrium and Lewis acid‐assisted CO2 activation has been proposed.