Delineation of the factors governing reactivity and selectivity in epoxide formation from ammonium ylides and aldehydes.
Diastereoselectivity in reactions of aryl-stabilised ammonium ylides are highly sensitive to the nature of the amine and the ylide substituent. DFT calculations are consistent with a mechanism in which reversibility in betaine formation [despite the high energy (and therefore instability) of ammonium ylides] is finely balanced due to the high barrier to ring closure.
School of Chemistry, University of Bristol, Cantock's Close, Bristol, UKBS6 1TS.
Raphaël
R
Robiette
Matteo
M
Conza
Varinder K
VK
Aggarwal