Intraannular functionalization of the 1,3-phenylene-19-crown-6 system via bromine–lithium exchange
作者:Ioannis D Kostas、Otto S Akkerman、Friedrich Bickelhaupt、Nora Veldman、Anthony L Spek
DOI:10.1016/s0022-328x(98)00884-5
日期:1999.1
(2-bromomercurio-1,3-phenylene)-19-crown-6 (13), bis[(1,3-phenylene-19-crown-6)-2-yl]mercury (14), and (2-bromomagnesio-1,3-phenylene)-19-crown-6 (15), respectively. The synthesis of the Grignard reagent 15 was also carried out by the direct reaction of 8 with magnesium; contrary to the corresponding 1,3-xylylene crown ethers, cleavage of the crown ether ring during the formation of 15 was not observed. At room temperature
与它的较低同系物1,3-亚苯基-16-皇冠-5(1)的行为相反,1,3-亚苯基-19-皇冠-6(2)在环内位置直接用n -BuLi锂化-2被发现是缓慢的并且不是定量的。因此,通过2-溴间苯二酚(7)的铯盐与五甘醇二溴化物的反应,合成了(2-溴-1,3-亚苯基)-19-皇冠-6(8)。8的晶体结构表明在晶胞中存在三个化学上相同的残基。在所有情况下,溴原子都从冠醚环中伸出。8与n的溴-锂交换反应在-65℃下在THF中2小时后定量提供-BuLi以提供所需的(2-硫代-1,3-亚苯基)-19-冠-6(4)。用氧化氘,二硫化二甲基,碘,二氧化碳,溴化汞(1或0.5摩尔当量)和溴化镁将4衍生化,得到(2-氘-1,3-亚苯基)-19-冠-6(2a), (2-甲硫基-1,3-亚苯基)-19-冠-6(10),(2-碘-1,3-亚苯基)-19-冠-6(11),(2-羧基-1,3-亚苯基)-19-皇冠-6(12),(2-溴汞-1