Department of Chemistry and Chemical Biology, University of California , 5200 North Lake Road, Merced, California 95343, United States.
Org Lett. 2017 Jun 2;19(11):2949-2952. doi: 10.1021/acs.orglett.7b01188. Epub 2017 May 17.
We report a unique example of utilizing unprotected amino acids for benzylic C-H fluorination via a radical process. α-Aminoalkyl radicals are readily generated via oxidative decarboxylation of unprotected amino acids using a simple silver(I) catalyst and Selectfluor, which serves as both a mild oxidant and source of electrophilic fluorine. Mechanistic investigation shows that coordination of the unprotected amino acid plays a crucial role in lowering the oxidation potential of Ag(I), enabling oxidation under mild conditions. Mono- or difluorination is possible by controlling the stoichiometry of amino acid and fluorine source.
我们报告了一个通过自由基过程利用未保护的氨基酸进行苄位 C-H 氟化的独特实例。α-氨烷基自由基可以通过使用简单的银（I）催化剂和 Selectfluor 从未保护的氨基酸中进行氧化脱羧轻松生成，后者既充当温和氧化剂又充当亲电氟源。机理研究表明，未保护的氨基酸的配位在降低 Ag(I)的氧化电位方面起着关键作用，从而可以在温和条件下进行氧化。通过控制氨基酸和氟源的化学计量比，可以实现单氟化或双氟化。
