Activation of C-CN bond of propionitrile: An alternative route to the syntheses of 5-substituted-1H-tetrazoles and dicyano-platinum(II) species

Abstract Reaction of trans -[Pt(N 4 CR) 2 (PPh 3 ) 2 ] 1 (R = Me 1a , Et 1b , Ph 1c , CH 2 CH 2 Ph 1d ) with propionitrile under reflux gives trans -[Pt(CN) 2 (PPh 3 ) 2 ] 2 along with 5-substitued-1 H -tetrazoles N 4 CR 3 (R = Me 3a , Et 3b , Ph 3c , CH 2 CH 2 Ph 3d ) in moderated to good yield, respectively. Treatment of cis -[Pt(N 3 ) 2 (PPh 3 ) 2 ] 5 with alkynes HC CR′ 6 (R′ = Ph 6a , p -MeC 6 H 4 6b ) under focused microwave irradiation leads, upon azide replacement, to the formation of the dialkynyl complexes trans -[Pt(C CR′) 2 (PPh 3 ) 2 ] 7 (R′ = Ph 7a , p -MeC 6 H 4 7b ) which also furnish the dicyano-platinum complex 2 in refluxing propionitrile. In both cases, the reactions leading to the formation of 2 proceed via an unusual oxidative addition, involving NC–C bond cleavage of two propionitrile molecules, and a reductive elimination process.