SnBrMe3 and dichalcogenides (ER)2 as oxidants: Synthesis of platinum(IV) complexes, and C···C and C···E coupling from pallada(IV)cyclopentane complexes and PdMe2(EPh){(pz)3BH} {E = O2C, S, Se; [(pz)3BH] = tris(pyrazol-1-yl)borate}

Abstract

Oxidation of the platinum(II) species [PtMe2{(pz)3BH}]- {[(pz)3BH]- = tris(pyrazol-1-yl)borate} by SnBrMe3 and the Group 16 oxidants (ER)2 results in the formation of a series of stable platinum(IV) complexes PtMe2(SnMe3){(pz)3BH} and PtMe2(ER){(pz)3BH} (ER = O2CPh, SMe, SPh, SeMe, SePh). In contrast, the palladium(II) analogue does not react with SnBrMe3 and reacts with (O2CPh)2 to form a 1:1 ratio of PdMe3{(pz)3BH} and a Pd(II)Me species. The oxidants (EPh)2 (E = S, Se) react with [PdMe2{(pz)3BH}]- to form unstable but NMR detectable species analogous to the platinum(IV) complexes followed by reductive elimination via C···C, C···S and C···Se bond formation processes. The pallada(II)cyclopentane species [Pd(CH2CH2CH2CH2){(pz)3BH}]- reacts with (ER)2 to form unstable species Pd(CH2CH2CH2CH2)(ER){(pz)3BH} (ER = O2CPh, SPh, SePh) followed by related decomposition reactions.