Transmetallation Tributyltin chloride

The allylstannane 474 is prepared by the reaction of allylic acetates or phosphates with tributyltin chloride and Sml2[286,308] or electroreduction[309]. Bu-iSnAlEt2 prepared in situ is used for the preparation of the allylstannane 475. These reactions correspond to inversion of an allyl cation to an allyl anion[3l0. 311], The reaction has been applied to the reductive cyclization of the alkenyl bromide in 476 with the allylic acetate to yield 477[312]. Intramolecular coupling of the allylic acetate in 478 with aryl bromide proceeds using BuiSnAlEti (479) by in situ formation of the allylstannane 480 and its reaction with the aryl bromide via transmetallation. (Another mechanistic possibility is the formation of an arylstannane and its coupling with allylic... 

Pyridylstannanes are accessed by transmetallation of pyridyllithium reagents with trialkyltin halides such as tributyltin chloride <20000L3373, 1998JA2805> and typically utilized as coupling partners in Stille reactions with... 

In complete analogy to silicon, trialkyltin chlorides react with the lithiated ferrocenylalkyl amines to give the corresponding tin derivatives (Fig. 4-26, bottom) trimethyltin [129] and tributyltin substituents [106] have been introduced by this method. The tin compounds are more reactive towards transmetalation than the silicon analogues and are therefore useful intermediates in the preparation of other derivatives [129], e.g., by C —C coupling to give chiral biferrocenes [106]. Several racemic planar chiral derivatives of ferrocenyltriethylstannane have been prepared via lithiated N,lV-dimethyl-ferrocenylmethylamine and similar compounds [150]. 

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