Isotopic Exchange of a Hydridoplatinum(II) Complex with Deuterium Oxide

Selectivity in reactions of alkyl-aryl-transition-metal complexes with electrophiles

“…41 The exchange of D for H between DC1 and trans-[PtHCl(PEt3)2] involves an intermediate [PtHDCl2(PEt3)2], which can be detected in solution. 42,43 Of course, it is possible that in these systems oxidative additions are particularly favorable and that in closely related systems the SE2 mechanism may be favored. When the oxidized intermediate cannot be detected, the SE(oxidative) mechanism must entail either rate-determining oxidative addition or a preequilibrium, with undetectably small concentration of oxidized intermediate, followed by rate-determining reductive elimination.…”

Oxidative Addition Reactions of Organoplatinum(II) Complexes with Nitrogen-Donor Ligands

“…The cleavage of metal−carbon σ bonds by electrophiles such as protic acids is of fundamental importance in organometallic chemistry, and the mechanism of this process has been the subject of several studies (Scheme ). − Detection of the alkyl(hydrido)platinum(IV) intermediate would provide definitive evidence for an oxidative addition pathway in the protonolysis of Pt−C bonds, although it is difficult to achieve owing to the facile reductive elimination of the alkane. Recently, a few groups have reported the detection and, in some cases, isolation of alkyl(hydrido)platinum(IV) complexes by protonation of the corresponding alkylplatinum(II) complex with HX.…”

Formation of a Stable Dihydrido(alkyl)platinum(IV) Complex by Water Activation

“…Attempts to prepare such complexes under aqueous conditions resulted in platinum(IV) hydroxo complexes with concomitant release of hydrogen gas, probably via rapid hydrolysis of short-lived platinum(IV) hydrido intermediates. , Consequently, most of the known hydrido(alkyl)platinum(IV) complexes were prepared and studied in the absence of oxygen and under anhydrous conditions. The dihydrido(alkyl)platinum(IV) complexes seemed to be more elusive than either the hydrido(alkyl)platinum(IV) or the dihydridodihaloplatinum(IV) complexes . Bercaw and co-workers, who studied extensively the individual steps of the catalytic oxidation of alkanes, have recently proposed a dihydrido(alkyl)platinum(IV) complex as a hypothetical intermediate in the low-temperature protonolysis of (PCy 3 ) 2 Pt(H)R (R = CH 3 , Ph) which produced methane or benzene …”