Reactions of organoplatinum complexes with dimethylamine-borane

Abstract

The reactions of dimethylamine-borane with platinum(II) or platinum(IV) triflate complexes gave, not the anticipated σ-complexes, but the respective hydridoplatinum complexes. The reaction with [Pt(OTf)Me₃(NN)], with NN = 2,2′-bipyridine (bipy) and 4,4′-di-t-butyl-2,2′-bipyridine (bu₂bipy), gave the rare stable bridging hydridoplatinum(IV) complexes [μ-H{PtMe₃(NN)}₂][OTf] and the reaction with [Pt(O₂CCF₃)Me(NN)] gave the unstable hydridoplatinum(II) complex [PtHMe(NN)]. The unstable hydridoplatinum(II) complexes could be trapped by reaction with methyl acrylate by forming the insertion products [PtCl(CHMeCO₂Me)(bipy)] and [Pt(CHMeCO₂Me)₂(bipy)]. The complex [PtCl(CHMeCO₂Me)(bipy)] reacted with methyl iodide to give [PtClIMe(CHMeCO₂Me)(bipy)], by cis oxidative addition, and the presence of two chiral centers in the product platinum(IV) complex allowed a detailed stereochemical pathway to be proposed.