Cobalt‐Catalyzed Enantio‐ and Diastereoselective Intramolecular Hydroacylation of Trisubstituted Alkenes

Enantio‐ and diastereoselective synthesis of trans ‐2,3‐disubstituted indanones is achieved by intramolecular hydroacylation of 2‐alkenylbenzaldehydes bearing trisubstituted alkenyl groups under cobalt‐chiral diphosphine catalysis. Notably, a high level of enantioselectivity is induced regardless of the stereochemistry (E /Z ratio) of the alkenyl group of the starting material. Deuterium‐labeling experiments shed light on the productive reaction pathways of the E ‐ and Z ‐isomers.     

Achiral Pyridine Ligand‐Enabled Enantioselective Radical Oxytrifluoromethylation of Alkenes with Alcohols

A conceptually novel strategy with achiral pyridine as the ancillary ligand to stabilize high‐valent copper species for the first asymmetric radical oxytrifluoromethylation of alkenes with alcohols under Cu^I/phosphoric acid dual‐catalysis has been developed. The transformation features mild reaction conditions, a remarkably broad substrate scope and excellent functional group tolerance, offering an efficient approach to a wide range of trifluoromethyl‐substituted tetrahydrofurans bearing an α‐tertiary stereocenter with excellent enantioselectivity. Mechanistic studies support the presumed role of the achiral pyridine as a coordinative ligand on copper metal to stabilize the key transient reaction species involved in the asymmetric induction process.     

Enantioselective Copper‐Catalyzed Intermolecular Amino‐ and Azidocyanation of Alkenes in a Radical Process

Asymmetric copper‐catalyzed intermolecular amino‐ and azidocyanation reactions of alkenes have been developed that proceed via a radical process in which a key benzylic radical intermediate is enantioselectively trapped by a chiral Box/Cu^II cyanide complex. A variety of enantiomerically enriched β‐amino/azido alkylnitriles were efficiently synthesized. The β‐azido alkylnitriles could be converted into a series of highly valuable optically active amine‐based building blocks and bioactive compounds.     

Enantioselective,Stereodivergent Hydroazidation and Hydroamination of Allenes Catalyzed by Acyclic Diaminocarbene (ADC) Gold(I) Complexes

The gold‐catalyzed enantioselective hydroazidation and hydroamination reactions of allenes are presented herein. ADC gold(I) catalysts derived from BINAM were critical for achieving high levels of enantioselectivity in both transformations. The sense of enantioinduction is reversed for the two different nucleophiles, allowing access to both enantiomers of the corresponding allylic amines using the same catalyst enantiomer.     

Dual Nickel‐ and Photoredox‐Catalyzed Enantioselective Desymmetrization of Cyclic meso‐Anhydrides

The enantioselective desymmetrization of cyclic meso‐anhydrides with benzyl trifluoroborates under nickel‐photoredox catalysis is described. The reaction tolerates a variety of sterically and electronically different trifluoroborates, as well as structurally unique cyclic anhydrides. The trans isomer of the keto‐acid products is also observed at varying levels dependent on the trifluoroborate identity and relative catalyst loading. A mechanism involving decarbonylation and Ni−C bond homolysis of a Ni^II adduct is proposed. This feature allows access to a trans keto‐acid as the major product in high enantioselectivity from a cis meso anhydride.