Rhodium-Catalyzed Asymmetric Addition of Arylboronic Acids to β-Nitroolefins: Formal Synthesis of (S)-SKF 38393

An efficient enantioselective addition of an array of arylboronic acids to various beta-nitrostyrenes catalyzed by a novel and reactive rhodium-diene catalyst (S/C up to 1000) was developed, providing beta,beta-diarylnitroethanes in good to high yields (62-99%) with excellent enantioselectivities (85-97% ee). The method was extended to 2-heteroarylnitroolefins and 2-alkylnitroolefins similarly providing the desired products with high enantioselectivities and yields. The usefulness of this method was demonstrated in the formal synthesis of the enantiomer of the dopamine receptor agonist and antagonist, SKF 38393.