Reactions of platinum(II)-alkyne and -alkynyl complexes with the hydroxy compounds HO(CH 2) 2X(X = Br, I, OH)

Abstract

The cationic solvento species trans-[Pt(Me)(PPh 3) 2(solv)][BF 4] (solv = CH 2Cl 2, Et 2O) reacts with 1.5 equiv. of p-tolylacetylene in the presence of a 10-fold excess of the hydroxylated compounds HOCH 2CH 2X (X = Br, I, OH) to give the corresponding (alkoxy)alkyl carbene complexes trans-[Pt(Me)=C(OCH 2CH 2X)CH 2( p-tolyl)(PPh 3) 2][BF 4 ( 1–3). Complexes 1–3 were also obtained by reaction of the acetylide complex trans-[Pt(Me)(CCR)(PPh 3) 2] (R = p-tolyl) in the presence of 1 equiv. of HBF 4 with an excess of HOCH 2CH 2X. The carbene complex trans-[Pt(Me)=C(OCH 2CH 2Cl)CH 2R(PPh 3) 2][BF 4] (R = p-tolyl) can be readily deprotonated by NEt 3 to afford the vinyl complex trans-[Pt(Me)C(OCH 2CH 2Cl)CH(R)(PPh 3) 2] ( 4). A similar behavior is observed also for 1–3 when treated with a base.