916991-29-2Relevant academic research and scientific papers
Origin of the E/Z Selectivity in the Synthesis of Tetrasubstituted Olefins by Wittig Reaction of α-Fluorophosphonium Ylides: An Explanation for the Low Stereoselectivity Observed in Reactions of α-Alkoxy Aldehydes
Depré, Dominique,Vermeulen, Wim A. A.,Lang, Yolande,Dubois, Jean,Vandevivere, Jan,Vandermeersch, Jeremy,Huang, Longchuan,Robiette, Rapha?l
supporting information, p. 1414 - 1417 (2017/03/23)
A series of tetrasubstituted fluoroalkenes were synthesized in good yield and high E/Z selectivity (up to 96/4) by Wittig reaction between α-heterosubstituted ketones and α-fluorophosphonium ylides. A detailed study of factors that control stereoselectivity in these reactions shows that stereoselectivity is the result of stabilizing CH···F and N···C=O interactions in the addition TS leading to the E isomer. This analysis provides a rationale for the observed decrease in selectivity for reactions of stabilized ylides with α-alkoxy aldehydes.
