89364-64-7Relevant academic research and scientific papers
Electrophilic cleavage of cyclopropylmethystannanes: An experimental comparison of σ-σ and σ-π conjugation
Lucke, Andrew J.,Young, David J.
, p. 3579 - 3583 (2005)
(Chemical Equation Presented) Cyclopropylmethyltrimethylstannanes undergo electrophilic cyclopropane cleavage in chloroform with simple inorganic electrophiles (H+, SO2, I2) in a homologous reaction to the SE′ cleavage of allylic stannanes. The σ-σ conjugation between the carbon-tin bond and cyclopropane orbitals observed spectroscopically in the parent cyclopropylmethyltrimethylstannane is responsible for a rate enhancement of ca. 102 toward iodinolysis, relative to comparable alkyl stannanes. This acceleration is considerably less, however, than the ca. 109-fold rate enhancement provided by the corresponding σ-π conjugation in allylic stannanes. Methanol-tin coordination appears to reduce the activating influence of the metal, promoting methyl cleavage over cyclopropane fission with acid and iodine. Decreased σ-σ conjugation can also explain the decreased reactivity of cyclopropyltriphenylstannane compared with its trimethyltin counterpart. Cyclopropylmethylstannanes do not undergo the synthetically useful addition of aldehydes under conditions that facilitate the corresponding reaction of allylic stannanes.
Regioselectivity in the Ring Opening of 2-Alkylcyclopropylmethyl Radicals: the Effect of Electronegative Substituents
Ratier, Max,Pereyre, Michel,Davies, Alwyn G.,Sutcliffe, Roger
, p. 1907 - 1916 (2007/10/02)
The regioselectivity of the ring-opening of the trans-2-alkylcyclopropylmethyl radical A to give the primary alkyl radicals B, or the secondary alkyl radicals C, has been investigated, where the groups R and/or CXY carry electronegative substituents.All these reactions gave principally the secondary alkyl radicals C, whereas, in the absence of electronegative substituents, ring-opening occurs in favour of the primary alkyl radicals B.This regioselectivity is interpreted in terms of the frontier orbital interactions which are involved.
