Enantioselective direct Michael addition of cyanohydrin ether derivatives to enones catalyzed by chiral bis(guanidino)iminophosphorane organosuperbase

Abstract

The direct use of cyanohydrin ether derivatives as the less acidic pronucleophile was achieved for the first time in the catalytic enantioselective Michael addition reaction under transition metal free conditions....

Asymmetric Auto-Tandem Catalysis with Chiral Organosuperbases: Intramolecular Cyclization/Enantioselective Direct Mannich-Type Addition Sequence

“…In addition, asymmetric variants require the control of enantioselectivity in the stereodetermining event. With these points in mind, we designed an addition reaction of alkynyl esters with imines, in which chiral bis­(guanidino)­iminophosphorane ( M )- 1 developed in our group , was used as the chiral Brønsted base catalyst (Scheme ). The first catalytic cycle involves the intramolecular cyclization of alkynyl ester 2 .…”