Synthesis of bulky tris[(dimethyl(alkyl/aryl)silyl)methyl]stannanes as radical based reducing agents

Abstract

The synthesis of novel bulky tris[dimethyl(ethyl/benzyl/ p-tolyl/α-naphthyl)silylmethyl]stannanes ( 1– 4) is described. Alkylation of SnCl 4 with Me 2(ethyl/ p-tolyl)SiCH 2MgBr ( 10– 11) gave mainly the triorganotin chlorides [(Me 2(ethyl/ p-tolyl)SiCH 2)] 3SnCl 14 and 15, which were isolated by silica gel chromatography. Reduction of 14 and 15 with LiAlH 4 in THF gave the corresponding triorganotin hydrides 1 and 2, respectively. [Me 2(benzyl/α-naphthyl)SiCH 2] 3SnCl 16 and 17, generated by the alkylation of SnCl 4 with Me 2(benzyl/α-naphthyl)SiCH 2MgBr 12 and 13, were inseparable from the minor product [Me 2(benzyl/α-naphthyl)SiCH 2] 2SnCl 2 18 and 19, respectively. Treatment of the mixtures of 16/18 and 17/19 with NaOH furnished the corresponding mixtures of stannoxanes, from which the hexakisdistannoxanes [Me 2(benzyl/α-naphthyl)SiCH 2] 6Sn 2O 20 and 22 were isolated from the minor dialkyltin oxide derivatives [Me 2(benzyl/α-naphthyl)SiCH 2] 2SnO in good yields. Reduction of 20 and 22 with BH 3 in THF gave [Me 2(benzyl/α-naphthyl)SiCH 2] 3SnH ( 3 and 4), respectively in good yields. 1H, 13C, 119Sn, 29Si NMR characteristics of the newly synthesized compounds are included.