Bis(trimethylsilyl)-, Trimethylsilyltrimethylgermyl-, and Bis(trimethylgermyl)diazomethane. Synthesis and Chemistry of Quantitative Silene and Germene Precursors

Article abstract of DOI:10.1021/ja00525a020

Convenient syntheses of bis(trimethylsilyl)diazomethane (1), trimethylsilyltrimethylgermyldiazomethane (22), and bis(trimethylgermyl)diazomethane (31), utilizing diazo transfer from tosyl azide to the carbanion derived from the corresponding bis(trimethylmetallo)methane or -chloromethane, are described.Both photolysis and thermolysis of 1 produce a carbene which rearranges via methyl migration to silene 3, which dimerizes.Trapping results with methanol, benzaldehyde, 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, and D2O indicate that silene formation is essentially quantitative.Thermolysis of 23 produces only products from silene intermediacy, but photolysis and trapping with MeOD reveal a competition between silene and germene formation which favors the silene by a factor of 4.Both photolysis and pyrolysis of 31 produce only products from the germene resulting from methyl migration to carbon.