Direct Synthesis of Protected Arylacetaldehydes by Palladium-Tetraphosphine-Catalyzed Arylation of Ethyleneglycol Vinylether
作者:Henri Doucet、Maurice Santelli、Isabelle Kondolff
DOI:10.1055/s-2004-829063
日期:——
Through the use of [PdCl(C3H5)]2/cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl) cyclopentane as a catalyst, a range of aryl bromides undergo Heck reaction with ethyleneglycol vinylether to give regioselectively protected arylacetaldehydes in good yields. The β-arylation products were obtained in the range 93-98% selectivity with electron-poor aryl bromides. Furthermore, this catalyst can be used at low loading, even for reactions of sterically hindered aryl bromides. The arylvinyl ethers intermediates undergo subsequent ketalization to give the corresponding 2-benzyl-1,3-dioxolane derivatives.
通过使用[PdCl(C3H5)]2/cis,cis,cis-1,2,3,4-四(二苯基膦甲基)环戊烷作为催化剂,一系列溴苯类化合物在 Heck 反应中与乙二醇乙烯醚反应,以良好的产率得到区域选择性保护的芳基乙醛。β-芳基化产物在电子贫乏的溴苯类化合物中获得了93-98%的选择性。此外,该催化剂在低负载下也可使用,甚至适用于空间位阻的溴苯类化合物的反应。芳基乙烯醚中间体随后经历缩酮化反应,得到相应的2-苄基-1,3-二氧戊环衍生物。