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.
A halon-free method for the synthesis of ‑bromofluoroolefins utilizing ethyldibromofluoro-acetate is disclosed via a Wittigtypereaction. The reaction system takes advantage of inexpensive and readily available reagents. The method was applied to a wide variety of aryl aldehydes. Both electron donating and electron withdrawing moieties on the aryl ring were tolerated and the desired olefin products
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.
Stereoselective synthesis of 1-bromo-1-fluorostyrenes
作者:Aleksey V. Shastin、Vasiliy M. Muzalevsky、Elizabeth S. Balenkova、Valentine G. Nenajdenko
DOI:10.1070/mc2006v016n03abeh002282
日期:2006.1
The effective and stereoselective one-pot synthesis of 1-bromo-1-fluorostyrenes from aromatic aldehydes based on a catalytic olefination reaction was elaborated.
Organophotocatalysis Enables the Synthesis of <i>gem</i>-Fluorophosphonate Alkenes