- Reaction of organoboron compounds with platinum(II) disolvento complexes
-
Cationic complexes cis-[Pt(S)2L2]2+ (L = PMe3, PEt3, or PPh3; S = H2O or MeOH) react with arylboron derivatives ([BPh4]-, [B(p-Tol)4]-, [B(m-Tol)4]-, BPh3, B(OMe)Ph2, B(OMe)2Ph, and B(OH)2Ph) to give trans-[Pt(Ar)(S)L2]+ which are isolated and characterized as their halo derivatives trans-[PtX(Ar)L2]. When L = PMe3, the transient formation of cis-[Pt(Ar)(S)L2]+ is also observed. The cation cis-[Pt(CH3CN)2-(PEt3)2] 2+, however, reacts with [BPh4]- only when at least some of the solvent is hydroxylic. However the phenylation and cis-trans isomerization reactions are slowed down so that the intermediate formation of cis-[Pt(Ph)(CH3CN)(PEt3)2]+ cation can be observed. It is shown that [BPh4]- is not the phenylating agent as it decomposes to BPh3 and C6H6 prior to the phenylation reaction. Other phenylboron derivatives such as BPh3, B(OMe)Ph2, B(OMe)2Ph, and B(OH)2Ph can transfer all of their phenyl groups to platinum. It is found that the phenyl transfer is strictly regioselective; i.e., only the C atom bonded to boron is found coordinated to platinum. When [B(Me)(Ph)3]- is used, either a methyl or a phenyl group can be transferred to platinum.
- Siegmann, Konstantin,Pregosin, Paul S.,Venanzi, Luigi M.
-
-
Read Online