Reactions of bis(trimethylsilyl)amino-substituted chlorosilanes [(Me3Si)(2)N]Me2-nPhnSiCl (n = 0, 1, 2) with lithium - Synthesis of bis(trimethylsilyl)amino-substituted silyl lithium compounds and disilanes [German]

摘要

The bis(trimethylsilyl)amino-substituted chlorosilanes [(Me3Si)(2)N]Me2-nPhnSiCl (1: n = 0, 2: n = 1, 3: n = 2) were allowed to react with lithium metal in tetrahydrofuran. 1 slowly reacts at room temperature to the homocoupling product {[(Me3Si)(2)N]Me2Si}(2) (4). An equimolar mixture of 1 and Me3SiCl gives 4 and the cross-coupling product [(Me3Si)(2)N]Me2Si-SiMe3 (5). The reaction of 2 at -78 degrees C leads to formation of bis(trimethylsilyl)aminosilyllithium [(Me3Si)(2)N]MePhSiLi (6), which reacts with Me3SiCl and 2 resp. to the corresponding disilanes [(Me3Si)(2)N]MePhSi-SiMe3 (7) and {[(Me3Si)(2)N]MePhSi}(2) (8). 6 undergoes partially self-condensation at -40 and 0 degrees C and the disilanyllithium [(Me3Si)(2)N]MePhSi-SiMePhLi (9) is formed. 3 reacts rapidly at 0 and -20 degrees C to give the silyllithium [(Me3Si)(2)N]Ph2SiLi (12). Treatment of 12 with Me3SiCl and 3 resp. affords the disilanes [(Me3Si)(2)N]Ph2Si-SiMe3 (13) and {[(Me3Si)(2)N]Ph2Si}(2) (14). The disilane R[(Me3Si)(2)NMeSi-SiMe3 (11) (R = 3,4,5,6-tetrakis(trimethylsilyl)cyclohex-1-enyl) is obtained by reaction of a mixture of 2 and Me3SiCl in molar ratio 1:5 with 6 equivalents of lithium in THF. The crystal structure of 11 is reported. [References: 34]