Hydroselenation and Carboselenation of Electron-Deficient Alkynes with Isolable (Hydrido)(selenolato)platinum(II) Complexes and a Selenaplatinacycle Bearing a Triptycene Skeleton
(Trip = 9-triptycyl) (3) with dimethyl acetylenedicarboxylate (DMAD) or methyl propiolate gave hydroselenation syn adducts. The reaction of [PtH(SeTrip)(dppe)] [dppe = 1,2-bis(diphenylphosphanyl)-ethane], which has a stronger phosphane σ-donor ligand than 3, with DMAD gave both syn and anti adducts. The reaction of 3 and DMAD in the presence of PPh 3 yielded no adducts. These observations indicate that