41923-73-3Relevant articles and documents
Reactivity of aldehydes with semi-stabilised arsonium ylide anions: Synthesis of terminal (E)-l,3-dienes
Habrant, Damien,Stengel, Bruno,Meunier, Stephane,Mioskowski, Charles
, p. 5433 - 5440 (2008/02/10)
A study of the reactivity of semi-stabilised arsonium ylide anions in olefinalion reactions is presented. The different ylide anions were generated by the addition of nBuLi to various arsonium halide derivatives: [Ph 2As(R)R']+X , where R and R′ are methyl, allyl, prenyl or benzyl groups. By using diallyldiphenylarsonium bromide (R = R′ = allyl) an olefinationprotocol was optimised allowing the efficient transformation of aliphatic aldehydes into terminal 1,3-dienes with a high selectivity for the E isomer (E/Z ratios ranging from 90:10 to 97:3). The olefination reactions of aldehydes with dissymmetric arsonium halides (R≠R′) are very chemoselective; with arsonium ylide anions the benzyl moiety is more reactive than the allyl moiety which is much more reactive than prenyl and methyl groups. Based on the experimental results, a mechanism is proposed for the reaction.