作者:Xu Cheng、Shou-Fei Zhu、Xiang-Chen Qiao、Pu-Cha Yan、Qi-Lin Zhou
DOI:10.1016/j.tet.2006.06.008
日期:2006.8
C2-Symmetric 9,9′-spirobifluorenes with 2,2′-, 3,3′-, and 4,4′-dihydroxyls were conveniently prepared from 1,2-dibromobenzene. The palladium-catalyzed coupling reaction of 1,2-dibromobenzene with methoxyphenylmagnesium bromide or methoxyphenylboronic acid provided methoxy substituted 2-bromobiphenyls. Lithium–bromine exchange with n-butyllithium, followed by reaction with dimethyl carbonate afforded
由1,2-二溴苯方便地制备具有2,2'-,3,3'-和4,4'-二羟基的C 2-对称的9,9'-螺二芴。1,2-二溴苯与甲氧基苯基溴化镁或甲氧基苯基硼酸的钯催化偶联反应提供了甲氧基取代的2-溴联苯。用溴化锂与正丁基锂交换,然后与碳酸二甲酯反应,得到二[2-(甲氧基苯基)苯基]酮作为关键中间体。由强路易斯酸和脱甲基作用引起的连续闭环产生二羟基-9,9'-螺二芴。外消旋二羟基产物通过使用手性拆分试剂的夹杂物结晶而拆分或通过手性HPLC分离。