Chapter 48 - Compounds with six-membered heterocyclic rings possessing two or more unusual hetero atoms

Abstract

Publisher Summary This chapter presents the compounds that are prepared with six-membered rings containing two or more unusual hetero-atoms. This is due to their use as precursors to unusual organo-metallic species and their formation as products from the trapping of reactive intermediates. Rings containing elements from different groups of the periodic table, such as boron, silicon, germanium, and phosphorus are arranged so that the highest group number has priority. Photolysis of peralkylpolystannanes gives rise to dialkyl stannylenes, which react as either R2Sn: or R2SnSnR2. Pyrolytic methods are useful in the preparation of a number of 1,3-disilacyclohexenes. The chapter focuses on boron compounds, such as 1,4-diborins; 1,3,5-triborimanes; 1,2,4,5-tetraborinanes; and compounds of silicon, germanium, and tin including 1,2-disilacyclohexanes; 1,2-disilacyclohex-3-enes; 1,2-disilacyclohex-4-enes; their benzologues and their germanium and tin analogues, 1,2-disilacyclohexadienes and their germanium analogues; 1,3-disilacyclohexanes and their tin analogues; and 1,3-disilacyclohexenes and their benzologues. A few other compounds with two hetero atoms are also discussed. The reactions of dichlorosilanes and silicon tetrachloride give several unusual polycyclic 1,4-disilacyclohexane derivatives. The reactive intermediate hexamethyl-1,4-disilabenzene can be trapped by various unsaturated substrates to give a range of polycyclic compounds.