Silicon, Germanium, Tin, and Lead Heterocycles

Space precludes an extensive survey of silicon, germanium, tin and lead substituted derivatives of cyclopentadiene (the siloles and analogues). Until 1979, few plumboles were known (79RTC437), but now, with the siloles, germoles and stannoles, they represent one of the most extensively studied areas of Group IV substituted heterocyclic chemistry. The references prefacing Section 1.20.9 cover reviews for this section. 

Review articles on carbodiimides were published by Khorana in 1953, by Kurzer and Douraghi-Zadeh in 1967, byMikolajczykandKielbasinski in 1981 and by Williams and Ibrahim in 1981. Carbodiimides containing silicon, germanium, tin and lead substituents were reviewed by Gordetsov and coworkers in 1982, N-functionalized carbodiimides by Vovk and Samarai in 1992 and polycarbodiimides by Pankratov in 1993. A review on the synthesis of heterocycles by the aza-Wittig reaction appeared in 1991. ... 

This subject was covered previously in CHEC(1984), together with other heterocyclic systems containing silicon, germanium, tin, or lead <1984CHEC(1)573>, and in CHEC-II(1996) <1996GHEC-II(1B)1175>. The present chapter is intended to update the previous editions with emphasis on major new preparations, reactions, and concepts. We have provided at the beginning of each main section a short summary of the major advances since the publication of the earlier chapters and also any omissions in CHEC-II(1996). This chapter, as the previous one by Conlin and Meagher... 

Heterocyclic Rings containing Silicon, Germanium, Tin or Lead 1.20.8.4 Polysila- and Polygerma-cyclopentanes... 

Draeger, M., Ross, L., Polygermanes and Heterocycles Rich in Germanium, Rev. Silicon Germanium Tin Lead Compounds 7 [1983] 299/445. 

Four-membered heterocyclic systems have been postulated to be involved as intermediates along the reaction pathway in a number of systems allowing olefin synthesis. This is the case of the Wittig reaction (phosphorus) and a family of related reactions the boron-Wittig (boron), the Peterson (silicon) 44 and the Peterson-type reactions (germanium, tin, lead). 5,l46 11 these systems,... 

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