Enantioselective synthesis of functionalized fluorinated dihydropyrano [2,3-c]pyrazoles catalyzed by a simple bifunctional diaminocyclohexane-thiourea

Enantioselective synthesis of functionalized fluorinated dihydropyrano[2,3-c]pyrazoles has been achieved via a diaminocyclohexane-thiourea catalyzed cascade Michael addition and Thorpe-Ziegler type cyclization in high yields (up to 98%) with moderate to good enantioselectivity (up to 90% ee). (C) 2014 Gang Zhao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.