304884-81-9Relevant academic research and scientific papers
Josiphos-Type Binaphane Ligands for Iridium-Catalyzed Enantioselective Hydrogenation of 1-Aryl-Substituted Dihydroisoquinolines
Nie, Huifang,Zhu, Yupu,Hu, Xiaomu,Wei, Zhao,Yao, Lin,Zhou, Gang,Wang, Pingan,Jiang, Ru,Zhang, Shengyong
supporting information, p. 8641 - 8645 (2019/10/17)
Convenient synthesis and useful application of a series of Josiphos-type binaphane ligands were described. The iridium complexes of these chiral diphosphines displayed excellent enantioselectivity and good reactivity in the asymmetric hydrogenation of challenging 1-aryl-substituted dihydroisoquinoline substrates (full conversions, up to >99% ee, 4000 TON). The use of 40% HBr (aqueous solution) as an additive dramatically improved the asymmetric induction of these catalysts. This transformation provided a highly efficient and enantioselective access to chiral 1-aryl-substituted tetrahydroisoquinolines, which were of great importance and common in natural products and biologically active molecules.
Direct Amidation of Carboxylic Acids through an Active α-Acyl Enol Ester Intermediate
Xu, Xianjun,Feng, Huangdi,Huang, Liliang,Liu, Xiaohui
, p. 7962 - 7969 (2018/06/18)
The development of a highly efficient and simple protocol for the direct amidation of carboxylic acids is described employing ynoates as novel coupling reagents. The transformation proceeds in good to excellent yields via in situ α-acyl enol ester intermediates formation under mild reaction conditions. This useful method has been demonstrated for a range of substrates to provide a succinct access to structurally diverse amides, including key intermediates of glibenclamide, tiapride hydrochloride, and nateglinide, and can be conducted on a mole scale.
