Efficient kinetic resolution of racemic 3-nitro-2H-chromenes by bifunctional thiourea afforded optically active (R)-3-nitro-2H-chromene derivatives with moderate to good enantioselectivities, which simultaneously gave the multifunctional 3,4-diphenyl-3a-nitrobenzopyrano-[3,4-c]-pyrrolidine-1,1-dicarboxylate derivatives with four vicinal chiral carbon centers.
Bifunctional acid–base ionic liquid for the one-pot synthesis of fine chemicals: Thioethers, 2H-chromenes and 2H-quinoline derivatives
作者:Maria J. Climent、Sara Iborra、Maria J. Sabater、Juan D. Vidal
DOI:10.1016/j.apcata.2014.05.004
日期:2014.7
A bifunctionalorganocatalyst with ionicliquid properties and with an optimized distancebetween the acid and basic sites efficiently activates electron deficient olefins for 1,4 conjugated addition, which can be incorporated in different one-pot transformations for the preparation of cyclic and acyclic compounds of biological and synthetic interest. More specifically, the catalyst can be successfully