130826-41-4Relevant academic research and scientific papers
Photochemical 1,3-stannyl rearrangement of allylic stannanes
Takuwa, Akio,Kanaue, Takashi,Yamashita, Koichi,Nishigaichi, Yutaka
, p. 1309 - 1314 (2007/10/03)
The photochemical 1,3-stannyl rearrangement of allylic stannanes has been investigated. The photorearrangement of (E)-cinnamyl(triphenyl)stannane is not observed in benzene under anaerobic conditions, while the photoinduced 1,3-stannyl migration takes place in the same solvent under aerobic conditions, or in the presence of organic halides or a radical-trapping agent to give a photoequllibrium mixture of the cinnamylstannane and its branched regioisomer, 1-phenylprop-2-enyl(triphenyl)stannane, with the latter predominating. Cinnamyl(trialkyl)stannanes and their homologues also afford the corresponding branched allylstannanes under similar photochemical conditions. These 1,3-stannyl migrations proceed intramolecularly via cinnamyl π-π* excitation in competition with homolytic (cinnamyl)C-Sn bond fission. In contrast, the 1,3-stannyl migration of crotyl- and prenyl-(tributyl)-stannanes is not efficient, but their triphenyl or dibutylphenyl derivatives undergo the 1,3-rearrangement via excitation of the phenyl group(s) on the tin atom to give a regioisomeric mixture of the starting linear tin compounds and the branched ones with the former predominating.
Synthesis of Allylstannanes and Vinylstannanes by the Stannyl-cupration of Allenes
Barbero, Asuncion,Cuadrado, Purificacion,Fleming, Ian,Gonzalez, Ana M.,Pulido, Francisco J.
, p. 327 - 332 (2007/10/02)
Stannyl-cupration of allenes followed by electrophilic attack gives allyl- and vinyl-stannanes with a variety of substitution patterns.The regiochemistry of the reaction depends upon the temperature at which the intermediate cuprate is quenched with an electrophile.With allene itself, the allylstannane-vinylcuprate 1-(tributylstannylmethyl)vinylcuprate 5, is the product of kinetically controlled addition, but the vinylstannane-allylcuprate 2-(tributylstannyl)allylcuprate 6, is thermodynamically lower in energy.The equilibrium between these isomers begins to take place between -100 and -78 deg C.
