Chiral mercaptoaryl-oxazolines as ligands in enantioselective copper-catalyzed 1,4-additions of Grignard reagents to enones
作者:Zhou Qi-Lin、Andreas Pfaltz
DOI:10.1016/s0040-4020(01)89379-0
日期:1994.4
A series of chiral enantiomerically pure mercaptoaryl-oxazolines has been synthesized. Copper(I) thiolate complexes derived from these ligands proved to be efficient catalysts for the 1,4-addition of Grignard reagents to cyclic enones. Enantioselectivities increased in the sequence cyclopentenone (16–37% ee) < cyclohexenone (60–72% ee) < cycloheptenone (83–87% ee).
A ligand-controlled branch-selective allylic C-H carboxylation through Pd catalysis is described. The developed catalytic system, which consists of Pd(OAc)(2), sulfoxide oxazoline (sox) as a ligand and benzoquinone as an oxidant, couples terminal alkenes and carboxylic acids to furnish the corresponding branched allylic esters with high regioselectivity.