Jouffroy Matthieu, Kelly Christopher B, Molander Gary A
Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania , 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States.
Org Lett. 2016 Feb 19;18(4):876-9. doi: 10.1021/acs.orglett.6b00208. Epub 2016 Feb 8.
Hypervalent alkylsilicates represent new and readily accessible precursors for the generation of alkyl radicals under photoredox conditions. Alkyl radicals generated from such silicates serve as effective hydrogen atom abstractors from thiols, furnishing thiyl radicals. The reactive sulfur species generated in this manner can be funneled into a nickel-mediated cross-coupling cycle employing aromatic bromides to furnish thioethers. The serendipitous discovery of this reaction and its utilization for the thioetherification of various aryl and heteroaryl bromides with a diverse array of thiols is described. The S-H selective H atom abstraction event enables a wide range of functional groups, including those bearing protic moieties, to be tolerated.
高价烷基硅酸盐是在光氧化还原条件下生成烷基自由基的新型且易于获得的前体。由这类硅酸盐产生的烷基自由基可作为从硫醇中夺取氢原子的有效试剂,生成硫自由基。以这种方式生成的活性硫物种可进入镍介导的与芳基溴化物的交叉偶联循环,以制备硫醚。本文描述了该反应的意外发现及其用于各种芳基和杂芳基溴化物与多种硫醇进行硫醚化反应的情况。S-H选择性氢原子夺取反应能够容忍包括带有质子部分的官能团在内的多种官能团。