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

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. [ABSTRACT FROM AUTHOR]