Unexpected chemoselectivity of cyclic enones on introducing additional chirality in diethanolamine ligand in catalytic asymmetric Michael addition reactions using heterobimetallics

A homochiral Al–Li heterobimetallic complex of diethanolamine was found to catalyze Michael addition reactions displaying high chemoselectivity with certain Michael acceptors and Michael donors. The heterochiral complex with stereochemical switch on the ligand displayed substrate generality. Herein we give the proposed mechanism and the effect of reversing the order of addition of substrates in causing the reversal of chemoselectivity.

Graphical abstractA homochiral Al–Li heterobimetallic complex of diethanolamine was found to catalyze Michael addition reactions displaying high chemoselectivity with certain Michael acceptors and Michael donors. The heterochiral complex with stereochemical switch on the ligand displayed substrate generality. Herein we give the proposed mechanism and the effect of reversing the order of addition of substrates in causing the reversal of chemoselectivity.Figure optionsDownload full-size imageDownload as PowerPoint slide