Stannyl group, migration

Apart from the ene products, photo-oxygenation of allylic stannanes produces stannyldioxolanes [87-89], Dioxolanes probably derive from ring opening of the intermediate perepoxide with 1,2-migration of the stannyl group to form a zwitterion ... 

Stereoselective formation of the C—Sn bond is usually observed in the addition of a trialkylstan-nyl anion to a C-C double bond or carbonyl group. Reactions are also described where a new C—Sn bond is stereoselectively formed via migration of the stannyl group or by stannylation of a chiral carbanion. 

Stannylphosphines react like tertiary phosphines with carbon disulfide, a P-C bond being formed the zwitterionic adducts, however, cannot be isolated and stabilize themselves by migration of the stannyl group to sulfur 138... 

In the reaction of O-Iithium-N,N-bis(silyl)hydF0xylaimde with trimethylchloiostannan N,0-bis(ter/-butyldimethylsilyl)-N-(trimethylstannyl)hydroxyIamine was fonned (Eq. 5). In contrast to the expected N,N-bis(siIyI)-0-stannylhydroxylamme the reaction product was N,0-bis(silyl)-N-stannylhydroxylamine. The migration of the stannyl group from the oxygen to the nitrogen atom can be explained with the Pearson concept. A solid-state structure was elucidated by X-ray diffraction method (Fig. 6). 

Besides iodine migration in fluoropyrazine serie the migration of the tributyl-stannyl group is known. When metalation of 2-fluro-3-tributylstannylpyrazine 383 was performed with 2.1 equiv. of LTMP with a short reaction time and was followed by protonation of the lithio derivative, compound 386, resulting from intramolecular tin/lithium exchange, was isolated in 63 % yield (Scheme 66) [215],... 

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