Asymmetric 1,4-hydrosilylations of alpha,beta-unsaturated esters.
Complexing catalytic amounts of CuH with a nonracemic JOSIPHOS or SEGPHOS ligand, together with stoichiometric PMHS, leads to exceedingly efficient and highly enantioselective 1,4-reductions of beta,beta-disubstituted enoates and lactones. An unprecedented substrate-to-ligand ratio of 7700:1 for this type of reaction is documented.
Lipshutz
Bruce H
BH
Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, USA. lipshutz@chem.ucsb.edu
Servesko
Jeff M
JM
Taft
Benjamin R
BR