Synthesis of NHC-Iridium(III) Complexes Based on<i>N</i>-Iminoimidazolium Ylides and Their Use for the Amine Alkylation by Borrowing Hydrogen Catalysis
作者:Vincent Guérin、Claude Y. Legault
DOI:10.1021/acs.organomet.0c00726
日期:2021.2.8
ylides, were used to synthesize NHC-iridium(III) complexes. Their catalytic activities were evaluated in the amine alkylation of anilines using borrowing hydrogen catalysis. The high-yielding synthesis of a small library of complexes allowed a rapid screening of the ideal steric bulk of the NHC unit and basicity of the anionic tether for the investigated model reaction. A bulky aromatic N group on
BF<sub>3</sub>·Et<sub>2</sub>O as a metal-free catalyst for direct reductive amination of aldehydes with amines using formic acid as a reductant
作者:Zhenli Luo、Yixiao Pan、Zhen Yao、Ji Yang、Xin Zhang、Xintong Liu、Lijin Xu、Qing-Hua Fan
DOI:10.1039/d1gc01468d
日期:——
direct reductive amination of aldehydes with amines using formic acid as a reductant under the catalysis of inexpensive BF3·Et2O has been developed. A wide range of primary and secondary amines and diversely substitutedaldehydes are compatible with this transformation, allowing facile access to various secondary and tertiary amines in high yields with wide functional group tolerance. Moreover, the
assistance of bases. Varieties of α-polyfluoroarylanilines were selectively produced with this protocol from polyfluoroarenes and N-alkylanilines, including natural products and pharmaceutical molecule derivatives. Mechanistic studies illustrated base-promoted photochemical C–H cleavage of the α-C–H bonds of alkylanilines to produce the N-α-carbon radical and then radical addition to polyfluoroarenes.
亲核仲烷基苯胺与多氟芳烃的直接和选择性氟芳基化首先通过可见光诱导的 C-H/C-F 偶联在碱的帮助下实现。利用该方案从多氟芳烃和N-烷基苯胺中选择性生产各种α-多氟芳基苯胺,包括天然产物和药物分子衍生物。机理研究表明,碱促进烷基苯胺的 α-C-H 键发生光化学 C-H 断裂,产生 N - α-碳自由基,然后自由基加成到多氟芳烃上。