Cyclization of Ph2Si(NHNHMe)2. II. Reactions with methyl iodide, HCl, and Ph2SiCl2, and thermolysis

Abstract

The reaction of Ph2Si(NHNHMe)2 (1) with MeI results in a mixture of two six-membered ring isomers, 1,2,4,5-tetraaza-1,4-dimethyl-3,3,6,6-tetraphenyl-3,6-disilacyclohexane (2), 45%, and 1,2,4,5-tetraaza-1,5-dimethyl-3,3,6,6-tetraphenyl-3,6-disilacyclohexane (3), 40%. The reaction of 1 with HCl or Ph2SiCl2 proceeds in a similar fashion. The thermolysis of 1 is studied from 25–600 °C. In the range of 250–300 °C, about 50% of 1 is converted into 2,3, and 1,2,4-triaza-1-methyl-4-methylamino-3,3,5,5-tetraphenyl-3,5-disilacyclopentane, 8. Possible pathways for the formation of 2,3, and 8 in these cyclization reactions are discussed.