A highly regio- and enantioselective organocatalyzed Michael addition of malonates to nitrodienes

Abstract

An organocatalyzed direct Michael addition of unsubstituted/substituted malonates, acetoacetate, or acetylacetones to conjugated nitrodienes using a cinchona alkaloid-based thiourea catalyst is disclosed. The addition products were formed in high yields and regioselectivity. The enantioselectivities of the addition products were high in most cases and could significantly be improved upon by a single recrystallization. The addition products easily undergo chemoselective nitro group reduction and subsequent lactamization with a high synthetic potential.