Counter Ion Effect in Au/Ag-Catalyzed Chemoselective 6-<i>endo</i>-<i>dig</i> N- and O-Cyclizations of Enyne–Urea System: Diversity-Oriented Synthesis of Annulated Indoles
作者:Sahaj Gupta、Dipankar Koley、Krishnan Ravikumar、Bijoy Kundu
DOI:10.1021/jo4013332
日期:2013.9.6
diversity-oriented synthesis of annulated indoles following MCR-post MCR modification concept is described. The reaction initially proceeds through the annulation of 2-(2,2-dibromovinyl)aniline, an isocyanate, and a terminal alkyne in a three-component tandem format via Cu/Pd-catalyzed cross coupling to afford N-1 and C-2 functionalized indole. In the subsequent step, the enyne–urea derivative undergoes chemo-
描述了遵循MCR-post MCR修改概念的,用于环状吲哚的分集式合成的两步协议。该反应最初通过铜/钯催化的交叉偶联,以三组分串联形式,通过2-(2,2-二溴乙烯基)苯胺,异氰酸酯和末端炔烃的环化进行,得到N -1和C -2。功能化的吲哚。在随后的步骤中,烯炔脲衍生物经受化疗和区域选择性6-内环化反应,得到ö -cyclized产物在金(I)/硝酸银的存在3和Ñ在MCR后修饰步骤中,在Au(I)/ AgOTf存在的条件下生成环化产物。在最近关于金催化中银效应的开创性工作之后进行的机械研究(师X J.上午 化学 Soc。 2012,134,9012)解释了抗衡离子对金/银催化regiodivergent途径中的作用。