The construction of main group heteroatom-stereogenic compounds is of great importance due to their intriguing chemical, physical, biological, and stereoelectronic properties. Despite that organoboron compounds are widely used in organic chemistry, the creation of a tetrahedral boron-stereogenic center in one enantiomeric form remains highly challenging. Given the labile nature of ligands attached to the tetracoordinate boron atom, only a handful of enantioenriched boron-stereogenic compounds have been reported via resolution or a chiral substrate-induced diastereoselective approach. To date catalytic asymmetric synthesis of boron-stereogenic compounds has remained unknown. Here, we demonstrate the first catalytic enantioselective construction of boron-stereogenic compounds via an asymmetric copper-catalyzed azide−alkyne cycloaddition (CuAAC) reaction. This enantioselective CuAAC reaction not only gives access to a wide range of novel highly functionalized boron-stereogenic heterocycles in high yields with good to excellent enantioselectivities but also produces optically active terminal alkyne and triazole moieties with various potential application prospects. Further transformation of the chiral tetracoordinate boron compounds delivers several complex heterocyclic entities bearing boron-stereogenic centers without the loss of enantiopurity. Moreover, the X-ray structure, the barrier to racemization, and the HOMO/LUMO gap of selected tetracoordinate boron compounds are investigated. Notably, these novel N,N π-conjugated boron-stereogenic compounds exhibit bright fluorescence. The optical properties, including circular dichroism, quantum yield, and circular polarized luminescence spectroscopies, are examined. These features expand the chemical space of the chiroptical boron-based dye platform, which could have great potential applications in chiral optoelectronic materials.

A Rh-catalyzed asymmetric synthesis of siliconstereogenic dihydrodibenzosilines featuring axially chiral 6membered bridged biaryls is demonstrated. In the presence of a Rh I catalyst with a chiral diphosphine ligand, a wide range of dihydrodibenzosilines containing both silicon-central and axial chiralities are conveniently constructed in excellent enantioselectivities via dehydrogenative C(sp 3 ) À H silylation. Absolute configuration analysis by single-crystal X-ray structures revealed a novel silicon central-to-axial chirality relay phenomenon, which we believe will inspire further research in the field of asymmetric catalysis and chiroptical materials.

A rational designed Ir­(III)-catalyzed enantioselective C–H amidation of dibenzyl sulfoxides through desymmetrization and parallel kinetic resolution is demonstrated. An Ir­(III) complex equipped with a t-butyl cyclopentadienyl ligand and paired with a modified chiral proline enables the highly enantioselective sulfoxide-steered C–H bond activation, providing an efficient and straightforward way to construct sulfur chiral centers. A wide range of dibenzyl sulfoxides and dioxazolones are compatible with this process, giving access to a variety of highly functionalized sulfoxide compounds with synthetically attractive amide substitution groups in good yields and enantioselectivities. Moreover, the flexible derivatization of the amidated sulfoxide was elaborated, providing various types of chiral sulfoxide scaffolds that would be potentially useful in asymmetric catalysis as chiral bidentate and tridentate ligands.

An anodic oxidation enabled efficient synthesis of hypervalent iodine(III) reagents from aryl iodides is demonstrated. Under mild electrochemical conditions, a range of aryliodine(III) reagents including iodosylarenes, (difunctionaliodo)arenes, benziodoxoles and diaryliodonium salts can be efficiently synthesized and derivatized in good to excellent yields with high selectivity. As only electrons serve as the oxidation reagents, this method offers a more straightforward and sustainable manner avoiding the use of expensive or hazardous chemical oxidants.

Ar hodium(I)-catalyzed enantioselective silylation of aliphatic C À Hbonds for the synthesis of silicon-stereogenic dihydrobenzosiloles is demonstrated. This reaction involves ahighly enantioselective intramolecular C(sp 3)ÀHsilylation of dihydrosilanes,f ollowed by as tereospecific intermolecular alkene hydrosilylation leading to the asymmetrically tetrasubstituted silanes.Awide range of dihydrosilanes and alkenes displaying various functional groups are compatible with this process,g iving access to av ariety of highly functionalized silicon-stereogenic dihydrobenzosiloles in good to excellent yields and enantioselectivities. Scheme 1. Enantioselective silylation of aliphaticC ÀHbonds.