Saitoh Terunobu, Yoshida Suguru, Ichikawa Junji
Department of Chemistry, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
J Org Chem. 2006 Aug 18;71(17):6414-9. doi: 10.1021/jo060662s.
Naphthalene-1,8-diylbis(diphenylmethylium) exhibits a unique electron-transfer reduction behavior due to the close proximity of the two triarylmethyl cations, which form a C-C bond while accepting two electrons, leading to 1,1,2,2-tetraphenylacenaphthene. The preparation of the dication was readily accomplished under anhydrous conditions starting from a cyclic bis(triarylmethyl) ether, derived from 1,8-dibromonaphthalene. The process proceeded via deoxygenation accompanying the formation of a disiloxane on treatment with a silylating agent (Me3SiClO4 or Me3SiOTf) in 1,1,1,3,3,3-hexafluoropropan-2-ol. The dication was successfully employed for oxidative coupling of N,N-dialkylanilines at the para-position to afford the corresponding benzidines in good to excellent yield.
萘-1,8-二基双（二苯基甲基鎓）由于两个三芳基甲基阳离子靠得很近而呈现出独特的电子转移还原行为，这两个阳离子在接受两个电子的同时形成一个C-C键，生成1,1,2,2-四苯基苊。从由1,8-二溴萘衍生而来的环状双（三芳基甲基）醚出发，在无水条件下很容易制备出该二价阳离子。在用甲硅烷基化试剂（Me3SiClO4或Me3SiOTf）在1,1,1,3,3,3-六氟丙-2-醇中处理时，该过程通过脱氧伴随二硅氧烷的形成而进行。该二价阳离子成功用于N,N-二烷基苯胺在对位的氧化偶联反应，以良好至优异的产率得到相应的联苯胺。
