[XI S. P. Mallela, 1. Bernai, RA Geanangel, Inorg. Chem. 1992. 31, 1626.[9] SP Mallela and RA Geanangel claimed the isolation of a colorless (!) THF adduct of 1 [fnorg. Chem. 1990, 29, 35251. Our own results (1 forms a brown THF solution) and the reported extreme Il9Sn highfield shift led us to doubt its identity. b) AA Arif, AH Cowley, TM Elkins, J. Orgunomet. Chem. 1987, 325, C11.[lo] S. Henkel, KW Klinkhammer, W. Schwarz, Angew. Chrm. 1994, 106. 721; Angew. Chem. Int. Ed. Engl. 1994, 33. 681. For earlier usage of bis (trimethy1si-1yl) amides in the syntheses of stannylenes and plumbylenes see for example ref.[6].[Ill KW Klinkhammer, W. Schwarz. Z. Anorg. Allg. Chem. 1993, 619, 1777; KW Klinkhdmmer, W, Schwarz, J Am. Chem. Soc., submitted.[12] The reaction of bis [bis (trimethylsilyl) amides] with hypersilanides is strongly dependent on the temperature and the solvent. Larger quantities of unknown paramagnetic compounds are formed in pentaue above-30" C. In the presence of toluene additional interesting products are found: At temperatures below-30 C mainly solvated alkali metal tris [tris (trimethylsilyl) silyl] stannanides or-plumbanides are obtained in addition to 1 and 2, respectively. At higher temperatures the main products are alkali metal derivatives of benzyl-