Catalytic Enantioselective Synthesis of Oxazolines with Vinylogous Isocyano Esters.

Vinylogous isocyano esters were prepared for the first time. They react with aldehydes to give chiral oxazolines bearing a pendant conjugated ester under synergistic silver/organocatalysis. The reaction is carried out using a bifunctional squaramide in combination with silver oxide and performs well with a number of aryl, heteroaryl, and cycloalkyl aldehydes, providing the expected heterocycles in good yields with good diastereoselectivity and enantiomeric excesses ranging from 60% to 95% ee.