已经开发了通过正式的脱氢-狄尔斯-阿尔德反应的金催化的炔基-炔烃环异构化反应,为各种取代的苯并[ b ]咔唑提供了诱人的途径。该反应可能是通过炔烃侧基区域选择性地攻击酮亚胺离子中间体并随后进行苯环化而进行的。该方法具有许多优点,例如高效,温和的反应条件和宽泛的官能团耐受性,可作为对乙酰胺炔炔的热DDA反应的高度有用的补充。
Fe-Catalyzed Novel Domino Isomerization/Cyclodehydration of Substituted 2-[(Indoline-3-ylidene)(methyl)]benzaldehyde Derivatives: An Efficient Approach toward Benzo[<i>b</i>]carbazole Derivatives
作者:Kartick Paul、Krishnendu Bera、Swapnadeep Jalal、Soumen Sarkar、Umasish Jana
DOI:10.1021/ol500505k
日期:2014.4.18
A new and efficient protocol to synthesize substituted benzo[b]carbazole derivatives has been demonstrated involving iron-catalyzed domino isomerization/cyclodehydration sequences from substituted 2-[(indoline-3-ylidene)(methyl)]benzaldehyde derivatives. The substrates could be easily made via Pd-catalyzed domino Heck–Suzuki coupling from 2-bromo-N-propargylanilide derivatives in high yields. Notably
已经证明了合成取代的苯并[ b ]咔唑衍生物的新的有效方案,该方案包括由取代的2-[(二氢吲哚-3-亚甲基)(甲基)]苯甲醛衍生物进行铁催化的多米诺骨化异构/环脱水序列。通过Pd催化的多米诺骨牌Heck-Suzuki偶联可以轻松地以高产率从2-溴-N-炔丙基苯胺衍生物制备底物。值得注意的是,通过合成多环苯并呋喃衍生物进一步例证了该两阶段多米诺策略的通用性和效率。