Copper-Catalyzed C(sp<sup>3</sup>)-C(sp<sup>2</sup>) Cross-Coupling: Synthesis of 4-Aryl-2-alkylamino-3-nitro-4<i>H</i>-chromenes
作者:H. Surya Prakash Rao、A. Veera Bhadra Rao
DOI:10.1002/ejoc.201402003
日期:2014.6
Inexpensive copper(II) acetate effectively catalyzes cross-coupling of electron-deficient as well as electron-rich arylboronic acids with 4-methylsulfanyl-2-alkylamino-3-nitro-4H-chromenes under near neutral conditions at room temp. to furnish a range of 4-aryl-4H-chromenes. This new strategy enabled substitution of the C(4)SMe group present on a sp3 hybridized carbon of the 4H-chromenes with aryl/heteroaryl
廉价的醋酸铜 (II) 在室温下近中性条件下有效催化缺电子和富电子芳基硼酸与 4-甲基硫基-2-烷基氨基-3-硝基-4H-色烯的交叉偶联。以提供一系列 4-芳基-4H-色烯。这种新策略使存在于 4H-色烯的 sp3 杂化碳上的 C(4)SMe 基团替换为芳基/杂芳基基团。机理探测表明,CuI-CuIII 循环参与催化。通过 Cu(OAc)2 和 Pd2(dba)3(Suzuki 耦合)催化实现了 C(4)SMe 和 C(6)Br 与芳基的一锅顺序取代。