Synthesis and Structures of Novel Phenyl-Bridged Bis(1-azaallyl) Alkali-Metal Compounds

Abstract

The series of dilithium bis(1-azaallyl) compounds [{o-{N(SiMe3)C(R)C(H)}2C6H4}{Li2(TMEDA)2}] (R = But (1), Ph (3)), [{m-{N(SiMe3)C(But)C(H)}2C6H4}{Li2(TMEDA)2}] (5), and [{p-{N(SiMe3)C(But)C(H)}2C6H4}{Li2(TMEDA)2}] (6) have been prepared by addition of the Li−C bond of [{o-/m-/p-(CHSiMe3)2C6H4}{Li2(TMEDA)2}] to a nitrile RCN (R = But, Ph) followed by a 1,3-shift of the SiMe3 group. Likewise, the addition of [{o-(CHSiMe3)2C6H4}{Li2(TMEDA)2}] to an isonitrile ButNC followed by 1,2-trimethylsilyl migration yielded [{o-{N(But)C(SiMe3)C(H)}2C6H4}{Li2(TMEDA)2}] (4). The dilithium compounds 1 and 6 can be further transferred to their potassium analogues [{o-{N(SiMe3)C(But)C(H)}2-C6H4}{K2(TMEDA)}]n (2) and [{p-{N(SiMe3)C(But)C(H)}2C6H4}{K2(THF)3}]2 (7) by reaction with ButOK. The structures of compounds 2−5 and 7 have been determined by X-ray structural analyses.