A Facile and Mild Method for the Synthesis of Terminal Bromofluoroolefins via Diethylzinc-Promoted Wittig Reaction
摘要:
Synthesis of 1-bromo-1-fluoroolefins was achieved in good yields via a Wittig reaction promoted by diethylzinc, even with nonactivated aldehydes and ketones as starting materials.
The synthesis of α-fluoroacrylates and α-bromo-α-fluoroalkenes was achieved in very good yields using aldehydes and ketones, triphenylphosphine, diethylzinc as promoter, and ethyl dibromofluoroacetate or dibromofluoromethane, respectively. A change in the addition sequence was critical in order to obtain exclusively α-fluoroacrylates in good yields.
Chromium-mediated fluoroalkenylation reactions of 1,1-dibromo-1-fluoroalkane and 1-bromo-1-fluoroalkene derivatives
作者:Akio Saito、Muga Nakagawa、Takeo Taguchi
DOI:10.1016/j.jfluchem.2005.05.003
日期:2005.8
CrCl2- and NiCl2-mediated coupling reactions of E/Z mixture of 1-bromo-1-fluoroalkenes with aldehydes proceeded in a high stereoselectivity to give the corresponding (Z)-2-fluoroallylic alcohol derivatives. On the other hand, in the reaction of 1,1-dibromo-1-fluoroalkane with CrCl2, (Z)-fluoroalkene derivative was formed via alpha-elimination reaction of the chromium carbenoid intermediate accompanying the concomitant 1,2-shift of beta-hydrogen. (c) 2005 Elsevier B.V. All rights reserved.
A Facile and Mild Method for the Synthesis of Terminal Bromofluoroolefins via Diethylzinc-Promoted Wittig Reaction
Synthesis of 1-bromo-1-fluoroolefins was achieved in good yields via a Wittig reaction promoted by diethylzinc, even with nonactivated aldehydes and ketones as starting materials.
A Novel Diastereoselective Synthesis of (<i>Z</i>)-Fluoroalkenes via a Nozaki−Hiyama−Kishi-Type Reaction
A highly diastereoselective and straightforward synthesis for (Z)-2-fluoroallylic alcohols via a Nozaki−Hiyama−Kishi-type reaction with the corresponding bromofluoroolefins was developed, providing an easy access to highly interesting fluorinated synthons.