Cobalt‐Catalyzed Asymmetric 1,4‐Reduction of β,β‐Dialkyl α,β‐Unsaturated Esters with PMHS

Abstract A cobalt‐catalyzed asymmetric reduction of β , β ‐dialkyl α , β ‐unsaturated esters with polymethylhydrosiloxane (PMHS) was reported to deliver the corresponding esters containing a chiral trialkyl carbon center at β ‐position with up to 97 % yield and 98 % ee . The chiral tridentate ligand oxazoline iminopyridine (OIP) could perform well for the asymmetric reduction instead of chiral bidentate ligands. This operationally simple protocol shows a broad scope of substrates using one equivalent of readily available PMHS as a cheap and easy‐to‐handle reductive reagent.