Synthesis of 1'-aryl-3''-(1H-benzotriazol-1-yl)-5',5'',6',6'',7',7a'-hexahydro-1'H,8''H-dispiro[indeno[1,2-b]quinoxaline-11,3'-pyrrolizine-2',7''-indolizin]-8''-ones via cycloaddition reaction

Activator free diastereoselective 1,3-dipolar cycloaddition: a quick access to coumarin based spiro multi heterocyclic adducts

A formal diastereoselective 1,3-dipolar cycloaddition of azomethine ylide and coumarin derivatives to construct coumarin based spiro multi heterocyclics has been described. The in situ generation of azo-ylide was achieved for various heterocyclic carbonyls (indenoquinoxaline and isatin). This transformation is also suitable for maleimide dipolarophiles for the synthesis of hydro-maleimide derivatives. These decarboxylative annulations neither required any catalyst nor any activator. Further the pure products were isolated by filtration from the reaction mixture after the reaction under ambient conditions.