Bis(2,2,2-trifluoroethyl)bromophosphonoacetate, a Novel HWE Reagent for the Preparation of (E)-α-Bromoacrylates: A General and Stereoselective Method for the Synthesis of Trisubstituted Alkenes
Keiko Tago and Hiroshi Kogen*
*Exploratory Chemistry Research Laboratories, Sankyo Co., Ltd., 2-58, Hiromachi, 1-chome Shinagawa-ku, Tokyo, 140-8710 Japan, Email: hkogenmy-pharm.ac.jp
K. Tago, H. Kogen, Org. Lett., 2000, 2, 1975-1978.
Horner-Wadsworth-Emmons (HWE) reactions of bis(2,2,2-trifluoroethoxy)bromophosphonoacetate with various aldehydes in the presence of t-BuOK and 18-C-6 provide (E)-α-bromoacrylates with high stereoselectivity, which are useful precursors for various C-C bond formations.
see article for more examples
Improved Preparation of Methyl
Bis(2,2,2-trifluoroethoxy)bromophosphonoacetate for the Stereoselective
Synthesis of (E)-α-Bromoacrylates:
A. Nakata, K. Kobayashi, H. Kogen, Chem. Pharm. Bull. 2013, 61, 108-110.
Hiroshi Kogen, September 23, 2020
Wittig-Horner Reaction, alkenyl bromides, unsaturated esters