Novel Synthesis of 1,4-Dialkoxy-5,6,7,8-multisubstituted-2,3-dicyanonaphthalenes through Electron Transfer from Mg Metal and Efficient Development of New Naphthalocyanines
作者:Hirofumi Maekawa、Ikuzo Nishiguchi、Takeshi Miyazaki、Aiko Harada、Yoshimasa Yamamoto
DOI:10.1055/s-0030-1259910
日期:2011.4
Novel methods for efficient synthesis of 1,4-diamyloxy-5,6,7,8-multisubstituted-2,3-dicyanonaphthalenes were successfully developed, starting from easily available 2,3-dicyanohydroquinone as a common single compound through only three steps, the first dibromination of 2,3-dicyanohydroquinone, the second Mitsunobu dialkylation of 2,3-dicyano-5,6-diboromo-1,4-hydroquinone, and the last Diels-Alder-type of cycloaddition between 1,4-alkoxy-2,3-dicyano-5,6-diboromobenzenes and multisubstituted furans, followed by reductive deoxygenation with Mg turning. The obtained 1,4-diamyloxy-5,6,7,8-multisubstituted-2,3-dicyanonaphthalenes were easily transformed into the corresponding naphthalocyanines in 20-45% yields which showed their λmax at 867-892 nm.
成功开发了合成1,4-二氨基氧-5,6,7,8-多取代-2,3-二氰基萘的高效新方法。该方法从易得的2,3-二氰基氢醌出发,仅通过三步反应:首先是2,3-二氰基氢醌的二溴化反应,其次是2,3-二氰基-5,6-二溴-1,4-氢醌的 Mitsunobu 二烷基化反应,最后是1,4-烷氧基-2,3-二氰基-5,6-二溴苯与多取代呋喃的 Diels-Alder 型环加成反应,随后通过镁还原脱氧反应得到产物。所得的1,4-二氨基氧-5,6,7,8-多取代-2,3-二氰基萘可以轻松转化为相应的萘酞菁衍生物,产率为20-45%,其最大吸收波长在867-892 nm之间。