A new class of readily available and conformationally rigid phosphino-oxazoline ligands for asymmetric catalysis
作者:Duan Liu、Qian Dai、Xumu Zhang
DOI:10.1016/j.tet.2005.03.111
日期:2005.6
A new class of conformationally rigid phosphino-oxazoline ligands 3 were synthesized via an efficient ortho-substitution of phenyl glycinol as the key step. Divergent synthetic routes for easy ligand modulation, as well as a procedure suitable for scale-up synthesis, were established. The catalytic potential of ligands 3 has been demonstrated in the highly enantioselective Ir-catalyzed hydrogenation
On the Mechanism of the Copper-Catalyzed Enantioselective 1,4-Addition of Grignard Reagents to α,β-Unsaturated Carbonyl Compounds
作者:Syuzanna R. Harutyunyan、Fernando López、Wesley R. Browne、Arkaitz Correa、Diego Peña、Ramon Badorrey、Auke Meetsma、Adriaan J. Minnaard、Ben L. Feringa
DOI:10.1021/ja0585634
日期:2006.7.19
The mechanism of the enantioselective 1,4-addition of Grignardreagents to alpha,beta-unsaturated carbonyl compounds promoted by copper complexes of chiral ferrocenyl diphosphines is explored through kinetic, spectroscopic, and electrochemical analysis. On the basis of these studies, a structure of the active catalyst is proposed. The roles of the solvent, copper halide, and the Grignardreagent have