An Efficient Approach to Azolyl-Substituted Steroids through Copper-Catalyzed Ullmann C-N Coupling
作者:Yury N. Kotovshchikov、Gennadij V. Latyshev、Nikolay V. Lukashev、Irina P. Beletskaya
DOI:10.1002/ejoc.201300719
日期:2013.12
Ullmann-type C–N coupling of vinyliodides and nitrogen heterocycles has been shown to be a straightforward and highly efficient approach to azolyl-substituted steroids. The amination reaction proved sensitive to steric effects exerted by the substituents in both iodide and heterocycle. The influence of reaction conditions (catalyst, base, solvent, and temperature) on conversion of the iodosteroid and
乙烯基碘化物和氮杂环的 Ullmann 型 C-N 偶联已被证明是一种直接且高效的唑基取代类固醇方法。胺化反应被证明对碘化物和杂环中的取代基所产生的空间效应很敏感。研究了反应条件(催化剂、碱、溶剂和温度)对碘甾类转化率和选择性的影响。在 100 °C 的二甲基亚砜中包含 10 mol-% CuI 和 20 mol-% 二戊酰甲烷和 K2CO3 的催化体系提供了最好的结果。详细的协议允许与各种取代的吲哚、咪唑、咔唑、吲唑和仲酰胺偶联的碘类固醇,以良好到极好的收率提供相应的唑基取代类固醇。