Enantioselective Synthesis of Spirothiazolones via Cooperative Catalysis

Abstract

Cooperative amino- and palladium catalysis utilizing heterocyclic systems containing strongly coordinating and adsorptive sulfur atom remains an underdeveloped area. Herein, we describe an enantioselective cyclization of enals with thiazole derivatives catalyzed with the combination of achiral Pd(0) complexes and chiral secondary amines.

Chiral spirocyclic thiazolones were produced in yields ranging from 41% to 98% with stereoselectivities (from 5:1 to 12:1 dr, and 95-99% ee). Moreover, the developed strategy allows access to highly substituted chiral cyclopentane derivatives by additional transformations of spirocyclic thiazolones.

Keywords

• enantioselective synthesis
• cooperative catalysis
• spirothiazolones
• thiazole derivatives