η3-Azatrimethylenemethane complexes of platinum. Structural characterization of (PPh3)2Pt(η3-CH2C(4-NC6H4NO2)CHPh)

Abstract η 3 -Azatrimethylenemethane complexes of platinum, (PPh 3 ) 2 Pt( η 3 -CH 2 C(NR)CHPh) ( 1a, b : R = 4-NO 2 C 6 H 4 ( a ), 4-MeC 6 H 4 ( b )), are conveniently prepared by reaction of (PPh 3 ) 2 Pt(C 2 H 4 ) with RNH 2 and PhCCCH 2 OTs (Ts4-MeC 6 H 4 SO 2 ) in CH 2 Cl 2 at 0–25°C, followed by deprotonation of the resulting η 3 -2-aminoallyl products ( 3 ) with LiPh. The structure of 1a was determined by X-ray crystallography. The Ph substituent on C(3) is oriented syn to the NC 6 H 4 NO 2 group. Other than that, the structure of 1a closely resembles that of the analogous η 3 -trimethylenemethane complex (PPh 3 ) 2 Pt( η 3 -CH 2 C-(C(CO 2 Me) 2 )CHPh) (V. Plantevin et al., Organometallics, 13 (1994) 3651). Complexes 1 react with TsNCO to give cyclic ureas, CH(Ph)N(Ts)C(O)N(R)C CH 2 ( 6 ).