Synthesis of oxazino[4,3-a]indoles by domino addition-cyclization reactions of (1H-indol-2-yl)methanols and vinyl selenones in the presence of 18-crown-6
Herein we report the synthesis of biologically relevant oxazino[4,3-a]indoles by an environmentally friendly Michael addition-cyclization cascade using potassium hydroxide in dichloromethane employing variously substituted vinyl selenones and (1H-indol-2yl)methanols. The addition of 18-crown-6, as a complexing agent, is crucial to achieve high chemo- and regio-selectivity.
在这里,我们报道了通过使用各种取代的乙烯基硒酮和(1 H-吲哚-2基)甲醇的氢氧化钾在二氯甲烷中的环境友好的迈克尔加成环化级联反应,通过环境友好的迈克尔加成环化级联反应合成生物相关的恶嗪[4,3- a ]吲哚。 添加18-crown-6作为络合剂对于实现高化学和区域选择性至关重要。
Regio- and site-selective activation of carbon-carbon double bonds to nucleophilic reagents. Cyclopropanation of vinylselenones with active methylene compounds
作者:Isao Kuwajima、Ryoichi Ando、Tomoo Sugawara
DOI:10.1016/s0040-4039(00)85916-x
日期:1983.1
A domino approach to pyrazino- indoles and pyrroles using vinyl selenones
Herein we disclose an efficient and flexible approach to biologically relevant 3,4-dihydropyrazino[1,2-alpha] indol-1(2H)ones and 3,4-dihydropyrrolo[1,2-alpha]pyrazin-1(2H)ones through a domino Michael/intra-molecular nucleophilic substitution pathway using potassium hydroxide in dichloromethane. Variously substituted vinyl selenones and 1H-indole-2-carboxamides or 1H-pyrrole-2-carboxamides have been employed with success in chemo and regio-selective processes. The introduction of an amino acid portion on the amidic function is well tolerated without racemization. (C) 2018 Elsevier Ltd. All rights reserved.