Polystyrene-supported (R)-2-piperazino-1,1,2-triphenylethanol: a readily available supported ligand with unparalleled catalytic activity and enantioselectivity

J Org Chem. 2005 Jan 21;70(2):433-8. doi: 10.1021/jo048310d.

Abstract

A very active and highly enantioselective catalytic resin, designed for minimal perturbation of the catalytic center by the polymer matrix, has been assembled in two steps from (S)-triphenylethylene oxide, piperazine, and Merrifield resin and tested in the enantioselective ethylation of aldehydes. 1-Arylpropanols of 94-95% ee are obtained in high yield by the use of only 2 mol % of catalytic resin at 0 degrees C for 4 h.