Preparation of some trans-bis(2 H-azirine)palladium dichloride complexes and the opening of their azirine rings in benzene

Abstract

The trans-bis(2 H-azirine)palladium dichloride complexes 2f, 2g, 2h and 2i are formed in the reaction of (C 6H 5CN) 2PdCl 2 with 3-phenyl- ( 1f), 2-phenyl-3-styryl- ( 1g) 2(formyl- N-phenylimine)-3-phenyl- ( 1h) and 2-styryl-3-phenyl-2 H-azirine ( 1i). The cleavage of the azirine rings of these complexes was studied in benzene at room temperature. The complexes 2f and 2g form the novel bis(η 2-3-chloro-1-azaallylpalladium) dichloride complexes 3f and 3g by rupture of the CN single bond. 2h reacts in the same way but the intermediate azaallylic palladium complex rearranges to form the bis(1,5-diazapentadienylpalladium) dichloride complex 5. 2i decomposes rapidly upon dissolution to form palladium dichloride and 2,5-diphenylpyrrole as the main products.