The first transition metal-ligand complex-catalyzed regioselective and stereoselective aminohalogenation of cinnamic esters

Transition metal-ligand complex-catalyzed regio- and stereoselective aminohalogenation of cinnamic esters has been developed using p-TsNCl₂ as the nitrogen and chlorine sources. Dichloro-(1,10-phenanthroline)-palladium (II) as the catalyst can be handled very conveniently due to its property of less hygroscopic as compared with other aminohalogenation catalysts. The reaction is suggested to proceed through the mechanism involving N-tosyl N-chloro aziridinium intermediate. Eight examples are presented with modest to good yields (56-82%) and excellent stereoselectivity (>10:1).