Trienamine-mediated asymmetric [4+2]-cycloaddition of α,β-unsaturated ester surrogates applying 4-nitro-5-styrylisoxazoles†
Abstract
Highly enantioselective organocatalytic [4+2]-cycloaddition of in situ generated trienamines with 4-nitro-5-styrylisoxazoles as α,β-unsaturated ester surrogates is presented. The synthetic utility of this strategy is demonstrated by transforming the formed cycloadducts into optically active carboxylates.