Active Isothiocyanates In Asymmetric Reactions

A series of chiral cinchona alkaloids and tertiary amine catalysts are prepared and used in the catalytic asymmetric cyclization reaction of amino-acid derived isothiocyanatos with azodicarboxylates. Under the optimal reaction conditions, the structural diversity 1,2,4-triazolines are prepared in good to high yield (up to 87%), and with good enantioselectivities (up to 95% ee).