Highly enantioselective and diastereoselective cycloaddition of cyclopropanes with nitrones and its application in the kinetic resolution of 2-substituted cyclopropane-1,1-dicarboxylates

Abstract

(Chemical Equation Presented) The multitalented catalyst 1/Ni(ClO 4)2 mediates both title processes (see scheme). Together the efficient asymmetric cycloaddition and a kinetic resolution/ cycloaddition provide access to both enantiomers of tetrahydro-1,2-oxazines. DME = 1,2-dimethoxyethane; R1 = aryl, vinyl; R2 = Et, Me, benzyl; R3 = Me, Ph; R4 = aryl, styryl. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.