Germanium-Peterson reaction

This reaction has been modified by the use of an a-silyl selenoacetamide to generate -olefins in preference and the use of an a-silyl thioether and A-cyclohexyl-(2-triethylsilylpropylidene)imine as of-silyl carbanion precursors. In addition, a germanium-Peterson reaction" and a tin-Peterson reaction" have been developed. Furthermore, an asymmetric version of the Peterson olefination has been developed by the use of an external chiral tridentate amino diether as a chiral ligand. ... 

The Germanium, Tin, and Lead Versions of the Peterson Reaction 2.5.5.1 The Cermanium-Peterson Reaction... 

Some examples of germanium versions of the Peterson reaction, such as syntheses of terminal alkenes, have been reported [383]. Peterson-type reactions of (trimeth-ylgermyl)acetate esters 235 with some aldehydes give the corresponding ( )-alkenes stereoselectively, whereas the use of the silyl analogues gives a mixture of the geometrical isomers (Scheme 2.145) [384, 385]. 

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,... 

Lead-Peterson olefination is achieved similarly to the germanium and tin versions, though the lead version is not advantageous over the latter reactions in most cases. A much simpler and more gentle elimination method applicable to the lead compounds is to pass the solution of the bis(triphenylplumbyl)ethanol derivative 249, which is synthesized from triplumbylmethane 248 and benzaldehyde, through a silica gel column (Scheme 2.152) [399]. 

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