Highly Diastereo- and Enantioselective Formal [4+2] Cyclization of Nitroalkenes and Unsaturated Ketoesters under Phase-Transfer Catalysis

A highly diastereo-and enantioselective formal [4 + 2] cyclization of alpha,beta-unsaturated ketoesters with nitroalkenes through a tandem asymmetric Michael addition-intramolecular Henry reaction under dihydroquinine-based phase-transfer catal-ysis, leading to a one-pot construction of four contiguous stereochemical centers and multiple functional groups with excellent diastereo-and enantioselectivities in high yields, has been developed. The ee values of some products were increased to similar to 100% in good yields after one crystallization.

Automated summary

In this study, a highly diastereo- and enantioselective formal [4 + 2] cyclization was achieved through a tandem asymmetric Michael addition-intramolecular Henry reaction using dihydroquinine-based phase-transfer catalysis. This method allowed for the one-pot construction of compounds with four contiguous stereochemical centers and multiple functional groups in high yields, with excellent diastereo- and enantioselectivities.