Transition-metal-catalyzed asymmetric C–H activation reactions generally rely on the design of ligands with sterically bulky groups to create a chiral environment for enantioinduction through steric repulsion. Here we describe an Ir­(III)-catalyzed asymmetric C–H activation enabled by noncovalent interactions. A broad range of sulfur-stereogenic sulfoximines was prepared in high yields with excellent enantioselectivities via the asymmetric C–H activation/annulation of sulfoximines with diazo compounds. Desymmetrization, kinetic resolution, and parallel kinetic resolution are compatible with this protocol. Detailed DFT calculations suggested that the N–H···O hydrogen bonding interaction between sulfoximine and the chiral carboxylic acid ligand was crucial for the high enantiocontrol. Moreover, chiral iridacycle intermediates were isolated, characterized, and subjected to stoichiometric reactions. Computational and experimental studies suggested that the C–H cleavage step was the rate- and enantio-determining step.

Sulfoximines bearing stereogenic sulfur atoms are ubiquitous motifs in pharmaceuticals, agricultural chemicals, and bioactive compounds. Herein, we report the synthesis of sulfur-stereogenic sulfoximines via Co­(III)/chiral carboxylic acid-catalyzed enantioselective C–H amidation. A broad range of cyclic and acyclic sulfur-stereogenic sulfoximines were isolated in good yields and enantioselectivities (up to an 86% yield and 1.5:98.5 er). The acyclic amidation products can be reduced to potential N,S-chiral sulfoxide ligands, which could be further transformed into recyclable chiral auxiliaries in the Pd-catalyzed diastereoselective C­(sp3)–H activation of aliphatic carboxylic acids.

Transition metal-catalyzed enantioselective C−H functionalization has emerged as an efficient and powerful strategy to access various chiral molecules. Recently, this strategy also provided a complementary pathway to the construction of P- and S-stereogenic compounds. In this short review, we summarize the development and applications of various catalytic systems, including Pd(II)/MPAA, Pd(0)/trivalent phosphorus chiral ligand, chiral CpxM(III) (M = Rh, Ir), half-sandwich d6 Ir(III) and Ru(II) with chiral carboxylic acid (CCA) ligand, Ir(I)/chiral bidentate boryl ligand, and Ir(I)/chiral cation, in the access of these chiral compounds via enantioselective C−H functionalization.

Sulfur-stereogenic containing benzo-fused heterocycles have gained much attention in drug discovery. However, the asymmetric synthesis of these chiral molecules with structural diversity is very challenging. Herein, we report the synthesis of chiral benzothiadiazine-1oxides with a seven-membered ring via achiral Ru(II)-catalyzed asymmetric [4 + 3] annulation of sulfoximines with α,β-unsaturated ketones assisted by chiral carboxylic acid (CCA). A broad range of chiral benzothiadiazepine-1-oxides bearing various functional groups could be prepared in up to 90% yield with up to >99% ee, expanding the chemical space of chiral sulfoximines. Notably, the oxidative cleavage of the double bonds in the products gave chiral N-benzoyl sulfoximines with a C−S chiral axis.