2-Alkylidenesulfol-3-enes by (regio- and) stereoselective cheletropic addition of SO2 to (di)vinylallenes.
[reaction: see text] The cheletropic addition of SO(2) to divinylallenes is regioselective, taking place at the most substituted vinylallene and at the E unit if vinyl groups of opposite geometry are competing. Diastereofacial differentiation results from the approach of the reagent from the less-substituted direction of the allene and from the concomitant disrotatory movement of the termini of the vinylallene to afford the sterically more congested 2-alkylidenesulfol-3-ene isomer. DFT computations confirm the regio- and the stereoselectivity of these cheletropic additions.
Souto
José A
JA
Departamento de Química Orgánica, Facultad de Química, Universidade de Vigo, 36310 Vigo, Spain.
López
Carlos Silva
CS
Faza
Olalla Nieto
ON
Alvarez
Rosana
R
de Lera
Angel R
AR