Ylides arsenic, antimony, bismuth

The ylides have been classified on the basis of the heteroalom covalently bonded to the carbanion. Accordingly, they can be differentiated into nitrogen ylide (Scheme 2), sulfur ylide Scheme 3, phosphorus ylide Scheme 4, arsenic ylide Scheme 5, antimony ylide (Scheme 6), bismuth ylide (Scheme 7) and thallium ylide (Scheme 8). 

These derivatives have not only provided new synthetic pathways but have shown improved thermal stability (as in the case of arsenic ylides) and a modified pattern of chemical reactivity. The donor properties of ylides 55, 24), and most of their synthetic applications 103), have been covered in other reviews and articles 3, 26) and are not duplicated here. The general organometallic chemistry of arsenic, antimony, and bismuth is the subject of the invaluable monograph by Doak and Freedman 11). The broad scope of phosphorus ylide and pentaorganophosphorane chemistry was covered in the leading multivolume series on organophosphorus chemistry edited by Kosolapoff and Maier 3, 21). Finally, the recent... 

A variety of ylides (e.g. 5) of arsenic, antimony and bismuth have been prepared under mild conditions via the reaction of diazo compounds with the appropriate three valent organometalloid. Schmidbaur s group continues to produce new ylide structures, for example (6).5 The lithiated aza-ylide (8) has been prepared directly from the parent... 

Arsenic, Antimony, and Bismuth.- (Diphenylarsino)methyl-lithium (203) has been prepared by either halogen-lithium or tin-lithium exchange from (204) or (205) respectively. Interestingly the reactivity of (203) depends on the method of preparation used, although the reasons for this are not known. A stereoselective synthesis of JE-a, -unsaturated aldehydes has been achieved by reacting aldehydes with the arsonium salt (206) in the presence of a weak base. The ylide derived from (206) shows a reasonable... 

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