Practical synthetic protocols of enantiopure 1,1′-binaphthyl-2,2′-dicarboxylic acid and 2,2′-dicyano-1,1′-binaphthyl starting from optically active dibromide precursor
作者:Takashi Hoshi、Eiji Nozawa、Masayoshi Katano、Toshio Suzuki、Hisahiro Hagiwara
DOI:10.1016/j.tetlet.2004.02.156
日期:2004.4
Dilithiation of optically active 2,2′-dibromo-1,1′-binaphthyl 2 with t-BuLi followed by carboxylation of the resulting dilithio-intermediate 3 with CO2 gave optically active 1,1′-binaphthyl-2,2′-dicarboxylic acid 1, which was further transformed to its dicyano derivative 4. Both of these transformations were carried out in a one-pot operation and the products were obtained in excellent yields with
的Dilithiation光学活性2,2- ' -二溴-1,1 '联萘2与吨正丁基锂,随后所得到的二锂-中间体羧3与CO 2,得到光学活性的1,1- '联萘-2,2 ' -二羧酸1,将其进一步转化为其二氰基衍生物4。这两种转化均在一锅操作中进行,并且以优异的收率获得了产物,没有可观察到的外消旋作用。