Enantio- and Diastereoselective NHC/Ni-Catalyzed Reductive Coupling of Alkenes with Carbonyls: Synthesis of Optically Active Indanols

We report a highly enantio- and diastereoselective reductive coupling of unactivated alkenes with aldehydes catalyzed by an N-heterocyclic carbene (NHC)/nickel complex, which provides efficient access to optically active indanol derivatives. Under mild conditions, a broad range of substrates bearing diverse functional groups─including electron-donating, electron-withdrawing, and heteroaromatic substituents─underwent smooth coupling to afford the corresponding products with excellent stereocontrol (all >99:1 dr, up to 97% ee). The method was also successfully extended to ketone substrates, delivering chiral tertiary alcohol derivatives with good enantioselectivity, further demonstrating its synthetic versatility. The use of a bulky chiral NHC ligand proved to be essential for achieving high stereoselectivity in the nickel-catalyzed process.