122450-59-3Relevant academic research and scientific papers
On the regioselectivity of the condensation of stabilized phosphoylids with 3-substituted phthalic anhydrides
Breau, Livain,Kayser, Margaret M.
, p. 569 - 573 (2007/10/02)
Condensations of stabilized phosphorane 1 with 3-substituted phthalic anhydrides were investigated.The importance of various effects influencing regio- and stereoselectivity of these reactions is discussed.It is proposed that the oxygen atom on the substituents in position 3 can act as a Lewis base toward the electron-deficient phosphorus of the ylid.The resulting complexation stabilizes the transition state for the reacction at the ortho carbonyl group, thus offsetting the usual steric and "push" effects, wich favour attack at the meta carbonyl function. - Key words: Wittig condensations, phthalic anhydrides, regioselectivity, stereoselectivity.
