Facile Single or Double C-H Bond Activation on eta~2-Platinum-Complexed Acetylenes by Interaction with [cis-PtR_2S_2] and [cis-PtR_2(CO)S] (R=C_6F_5,S=Thf)

摘要

The mu-hydride mu-acetylide [cis,cis-(PPh_3)_2Pt(mu-H)(mu-1kappaC~(alpha):eta~2-Cident toCPh)Pt(C_6F_5)_2] (1b) and the mu-vinylidene [cis,cis-(CO)(C_6F_5)_2Pt(mu-C=CHPh)Pt(PPh_3)_2] (2) have been prepared by reaction of the eta~2-phenylacetylene Pt(0) complex [Pt(eta~2-HCident toCPh)(PPh_3)_2] as the starting material with the disolvated [cis-PtR_2S_2] and the monosolvated [cis-PtR_2(CO)S] (R=C_6F_5,S=tetrahydrofuran) complexes,respectively.Extension of these reactions to the mu-eta~2:eta~2-bis-(alkyne)diplatinum(0) precursor [{Pt(PPh_3)_2}_2{mu-eta~2:eta~2-(1,4-HCident toC)_2C_6H_4}] and 2 equiv of the corresponding solvated complexes affords the bis(mu-hydride) mu-diethynylbenzene [{cis,cis-(PPh_3)_2Pt(mu-H)Pt(C_6F_5)_2}_2{mu-1kappaC~(alpha):4kappaC~(alpha'):eta~2:eta~2-(1l,4-Cident toC)_2C_6H_4}] (4b) and the bis(mu-vinylidene) [{cis,cis-(CO)(C_6F_5)_2PtPt(PPh_3)_2}_2{mu_4-1kappaC~(alpha):2kappaC~(alpha):3kappaC~(alpha'):4kappaC~(alpha')-(1,4-C=CH)_2C_6H_4}] (3) tetranu-clear derivatives.The preparation of the isomeric [{trans-(PPh_3)(C_6F_5)Pt(mu-H)Pt(C_6F_5)-(PPh_3)}_2{mu-1kappaC~(alpha):4kappaC~(alpha):eta~2:eta~2-(1,4-Cident toC)_2C_6H_4}] (4a) was achieved by reaction of [{trans-PtH(PPh_3)_2}_2{mu-1kappaC~(alpha):2kappaC~(alpha')-(1,4-Cident toC)_2C_6H_4}] with 2 equiv of [cis-PtR_2S_2].Single-crystal X-ray structural determinations of 1b,2,3,and 4b are reported.