Ruthenium–NHC–Diamine Catalyzed Enantioselective Hydrogenation of Isocoumarins
作者:Wei Li、Mario P. Wiesenfeldt、Frank Glorius
DOI:10.1021/jacs.6b13124
日期:2017.2.22
A novel and practical chiral ruthenium-NHC-diamine system is disclosed for the enantioselective hydrogenation of isocoumarins, which provides a new concept to apply (chiral) NHC ligands in asymmetriccatalysis. A variety of optically active 3-substituted 3,4-dihydroisocoumarins were obtained in excellent enantioselectivities (up to 99% ee). Moreover, this methodology was utilized in the synthesis of
Copper nanoparticles catalyzed economical synthesis of 3-substituted isocoumarins from 2-chlorobenzoic acids/amides and 1,3-diketones
作者:Xiaowen Wang、Chaolong Wu、Youwen Sun、Xiaoquan Yao
DOI:10.1016/j.tetlet.2017.07.001
日期:2017.8
Copper nanoparticles were utilized as a highly efficient catalyst for a facile and economical synthesis of 3-substituted isocoumarins with 2-chlorobenzoic acids and 1,3-diketones as starting materials. The copper nanoparticles catalyst showed highly catalytic activity for the 2-chloro-substituted substrates to afford 3-substituted isocoumarins in good to excellent yields. Furthermore, good catalytic
A new protocol for the synthesis of polysubstituted isocoumarins from 2-iodobenzoic acid and beta-diketone compounds has been developed. The occurrence of C-arylation cyclization reaction in transition-metal-free systems and ortho-induced substrates has been exploited. Reactions using these inexpensive conditions have displayed high functional group tolerance and excellent yields. (c) 2012 Elsevier Ltd. All rights reserved.