Syntheses of cyclic diselenides through diselenolates and the following deselenation reactions by means of three ways were studied. The preparation of the cyclic diselenides in the presence of excess sodium borohydride gave thirty-eight diselenides containing diselena[3.3]cyclophanes and alicyclic diseleno compounds in high yields in addition to two triple-bridged selenacyclophanes. Photodeselenation
Diaza[3.3]cyclophanes were converted to the corresponding [2.2]cyclophanes via their N-nitroso derivatives by reductive extrusion of nitrogens. This reaction is simple, clean and mild, and may be an alternative synthetic way of [2.2]cyclophanes.
General Ambient Temperature Benzylic Metalations Using Mixed-Metal Li/K-TMP Amide
作者:Atul Manvar、Patricia Fleming、Donal F. O’Shea
DOI:10.1021/acs.joc.5b01540
日期:2015.9.4
carbanions utilized for nucleophilic addition and Peterson olefination reactions. Direct C–C couplings mediated by 1,2-dibromoethane provided entries into bibenzyls and [2.2]metacyclophanes. Comparison of reaction outcomes with the same reactions carried out in THF at −78 °C showed no negative effects for conducting the reactions under these milder more user-friendly conditions.
使用由KO t Bu,BuLi和2,2,6,6,-四甲基哌啶(TMP(H ))。KO t的混合庚烷中的Bu,BuLi和TMP(H)给出了一种基础混合物的溶液,当用于氘标记实验时,证实了这三种试剂组分对反应性和选择性的要求。该反应方案在操作上简单明了,并且发现可适用于多种底物。在生成金属化产物时,它们在庚烷中于环境温度下以多种合成上有用的方式反应。所示实例包括苄基三甲基硅烷和α,α-双(三甲基甲硅烷基)甲苯试剂的产生,它们是用于亲核加成和彼得森烯化反应的苄基阴离子和α-甲硅烷基碳负离子的替身稳定替代物。由1,2-二溴乙烷介导的直接C-C偶联提供了联苄和[2.2]甲基环已烷的入口。
Deselenation of diselenacyclophanes —a new synthetic method of [2.2]cyclophanes—
作者:Hiroyuki Higuchi、Soichi Misumi
DOI:10.1016/s0040-4039(00)85897-9
日期:1982.1
diselena[3.3]cyclophanes were prepared by coupling of bisselenocyanates and bis(bromomethyl)benzenes in good yields. The benzyne Stevens rearrangement-Raney Ni hydrogenolysis method gave good yields of double- and triple-layered cyclophanes from the diselenides, though the flash pyrolysis method gave them in low yields.