.ALPHA.-Bromo-.ALPHA.,.ALPHA.-difluoroallyl Derivatives as Synthetic Intermediate. Nucleophilic Substitution of .ALPHA.-Bromo-.ALPHA.,.ALPHA.-difluoroallyl Derivatives in the Presence of Palladium Catalysts.
作者:Masayuki KIRIHARA、Tomofumi TAKUWA、Maiko OKUMURA、Takahiro WAKIKAWA、Hiroki TAKAHATA、Takefumi MOMOSE、Yoshio TAKEUCHI、Hideo NEMOTO
DOI:10.1248/cpb.48.885
日期:——
The palladium catalyzed nucleophilic substitution ofα-bromo-α, α-difluoroallyl derivatives turned out to be an efficient method for the preparation of several fluorinated organic molecules. Several soft carbon nucleophiles regioselectively reacted with 3-bromo-3, 3-difluoropropene (BDFP) to give the 3-substituted 1, 1-difluoroalkenes. Phenylzinc chloride and tributylphenyltin afforded 1-fluoro-1, 3-diphenylpropene. The radical bromination of 3-substituted 1, 1-difluoroalkenes provided 1-substituted BDFPs, and a 1-substituted BDFP reacted with carbon nucleophiles to give 1, 3-disubstituted 3, 3-difluoroalkenes. For the reaction of nitrogen nucleophiles with BDFP, an amine and the sodium salts of the carbamates reacted with BDFP at the γ-position. However, the sodium salts of the sulfoneamide predominantly attacked at the α-position.
钯催化α-溴-α,α-二氟烯丙基衍生物的亲核取代反应被证明是制备多种含氟有机分子的有效方法。几种软碳亲核物与 3-溴-3, 3-二氟丙烯(BDFP)发生了选择性反应,生成了 3-取代的 1, 1-二氟烯烃。苯基氯化锌和三丁基苯基锡得到了 1-氟-1,3-二苯基丙烯。3 取代的 1,1-二氟烯烃通过自由基溴化反应生成 1 取代的 BDFP,而 1 取代的 BDFP 与碳亲核物反应生成 1,3-二取代的 3,3-二氟烯烃。在氮亲核物与 BDFP 的反应中,胺和氨基甲酸酯的钠盐在 γ 位与 BDFP 发生反应。然而,磺酰胺的钠盐主要在 α 位发生反应。