文摘
New chiral thioureas 1–8 containing 1,2-ethylendiamine or trans-1,2-diaminocyclohexane as the carbon skeleton, and containing an (S)-α-phenylethyl group have been prepared (79–98 % yield). Thioureas 1–8 were used as ligands for the zinc-based catalyzed asymmetric hydrosilylation of acetophenone with polymethylhydrosiloxane (PMHS). The best result was achieved with monothiourea 1 (up to 75 % ee), in toluene and a catalyst load of 5 mol % .