Jiang Heng, He Jian, Liu Tao, Yu Jin-Quan
Department of Chemistry, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States.
J Am Chem Soc. 2016 Feb 17;138(6):2055-9. doi: 10.1021/jacs.5b13462. Epub 2016 Feb 4.
Pd(II)-catalyzed olefination of γ-C(sp(3))-H bonds of triflyl (Tf) and 4-nitrobenzenesulfonyl (Ns) protected amines is achieved. Subsequent aza-Wacker oxidative cyclization or conjugate addition of the olefinated intermediates provides a variety of C-2 alkylated pyrrolidines. Three pyridine- and quinoline-based ligands are developed to match different classes of amine substrates, demonstrating a rare example of ligand-enabled C(sp(3))-H olefination reactions. The use of Ns protecting group to direct C(sp(3))-H activation of alkyl amines is also a significant step toward practical C-H functionalizations of alkyl amines.
实现了钯(II)催化的三氟甲磺酰基(Tf)和4-硝基苯磺酰基(Ns)保护胺的γ-C(sp³)-H键的烯基化反应。随后,烯基化中间体的氮杂瓦克氧化环化或共轭加成反应可提供多种C-2烷基化吡咯烷。开发了三种基于吡啶和喹啉的配体以匹配不同类别的胺底物,这是配体促进的C(sp³)-H烯基化反应的一个罕见例子。使用Ns保护基来指导烷基胺的C(sp³)-H活化也是实现烷基胺实际C-H官能化的重要一步。