New synthesis of allylidenecyclobutanes by the reaction of cyclobutylmagnesium carbenoids with vinyl sulfones

Coupling Reaction of Magnesium Alkylidene Carbenoids with α-Sulfonyl­allyllithiums: An Efficient Route to Multi-Substituted Vinylallenes

“…6c Meanwhile, we also found that α-sulfonylallyllithiums reacted with cyclobutylmagnesium carbenoids to give allylidenecyclobutanes (Scheme 1, equation 2). 7 If the general concept of these reactions could be extended to the reaction of magnesium alkyli-dene carbenoids with α-sulfonylallyllithiums, that is, if vinylidene components could be coupled with allylidene components through a double bond, 8 we reasoned that it would be an efficient route to vinylallenes (Scheme 1, equation 3). Herein, we report the synthesis of multisubstituted vinylallenes from 1-chlorovinyl sulfoxides and allyl sulfones as well as vinyl sulfones.…”