INTRAMOLECULAR Si-C AND C-H BOND ACTIVATION IN A PLATINUM COMPLEX LEADING TO THE FORMATION OF THE PLATINACYCLES

摘要

Reduction of dichloroplatinum complex dl-1 bearing two bulky aromatic substituents, Bbt groups (2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(tri-methylsilyl)methyl]phenyl), by sodium metal gave a unique platinacycle 2, a hydridoplatinum complex of [PtH{CH2SiMe2CH(SiMe3)C6H2-3-CH(SiMe3)2-5-C(SiMe3)3-2-P(Me)CH2CH2 (Me)PBbt}], which seems to be most likely formed via the initial formation of the corresponding Pt(0) complex and the subsequent intramolecular insertion of the Pt(0) center to the H-CH2 bond of the o-bis(trimethylsilyl)methyl group of the Bbt group. On heating, the hydridoplatinum complex 2 underwent further intramolecular Si-C activation giving another type of platinacycle, [PtMe{SiMe2CH(SiMe3)C6H2-3CH(SiMe3)2-5-C(SiMe3)3-2-P(Me)CH2CH2(Me)PBbt}] (4), which has a (methyl)(silyl)-platinum complex structure.