Fast, solvent-free asymmetric alkynylation of prochiral sp3 C–H bonds in a ball mill for the preparation of optically active tetrahydroisoquinoline derivatives
作者:Jingbo Yu、Zhenhua Li、Kanyan Jia、Zhijiang Jiang、Menglu Liu、Weike Su
DOI:10.1016/j.tetlet.2013.02.007
日期:2013.4
Solvent-free asymmetric cross-dehydrogenative-coupling (CDC) reaction between the sp(3) C-H bond of prochiral CH2 and terminal alkynes was first studied under High-Speed Ball-Milling conditions. A series of optical active 1-alkynyl tetrahydroisoquinoline derivatives were achieved by using recoverable copper balls together with PyBox chiral ligand in the presence of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). All coupling products were obtained in good yields at short reaction time with enantiomeric excesses up to 79%. (C) 2013 Elsevier Ltd. All rights reserved.
Dual Catalysis: Combination of Photocatalytic Aerobic Oxidation and Metal Catalyzed Alkynylation Reactions-CC Bond Formation Using Visible Light
作者:Magnus Rueping、René M. Koenigs、Konstantin Poscharny、David C. Fabry、Daniele Leonori、Carlos Vila
DOI:10.1002/chem.201200050
日期:2012.4.23
Shedding new light on the right combination of catalysts: A new dual catalytic system for efficient CH functionalization was developed. The appropriate choice of two metal catalysts allows the oxidativealkynylation of tertiary amines under mild and sustainable reaction conditions.