102011-15-4Relevant articles and documents
Efficient and Practical Syntheses of Enantiomerically Pure (S)-(-)-Norcryptostyline I, (S)-(-)-Norcryptostyline II, (R)-(+)-Salsolidine and (S)-(-)-Norlaudanosine via a Resolution-Racemization Method
Zhu, Ruiheng,Xu, Zhangli,Ding, Wei,Liu, Shiling,Shi, Xiaoxin,Lu, Xia
, p. 1039 - 1048 (2014)
Four racemic tetrahydroisoquinolines (RS)-(±)-1-4 were prepared from homoveratrylamine via amidation, Bischler-Napieralski reaction and the subsequent reduction. The enantiomerically pure tetrahydroisoquinolines (S)- (-)-norcryptostyline I [(S)-(-)-1], (S)-(-)-norcryptostyline II [(S)-(-)-2], (R)-(+)-salsolidine [(R)-(+)-3] and (S)-(-)-norlaudanosine [(S)-(-)-4] were then obtained in 45%, 40%, 41% and 38% yields, respectively, via resolution of the racemic compounds (RS)-(±)-1-4 with half equivalent of chiral acids. In addition, the enantiomerically enriched compounds (R)-(+)-1, (R)-(+)-2, (S)-(-)-3 and (R)-(+)-4 from the mother liquors were efficiently racemized via a one-pot redox method in almost quantitative yields.
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.
Mild rhodium(III)-catalyzed cyclization of amides with α,β- unsaturated aldehydes and ketones to azepinones: Application to the synthesis of the homoprotoberberine framework
Shi, Zhuangzhi,Grohmann, Christoph,Glorius, Frank
, p. 5393 - 5397 (2013/06/05)
Seven! The title reaction can be described as an intermolecular annulation involving tandem C-H activation, cyclization to give the seven-membered ring, and condensation steps. Biologically interesting azepinone derivatives can be prepared in this way. Th
