Synthesis of new mono-N-tosylated diamine ligands based on (R)-(+)-limonene and their application in asymmetric transfer hydrogenation of ketones and imines
作者:Piotr Roszkowski、Jan K. Maurin、Zbigniew Czarnocki
DOI:10.1016/j.tetasy.2013.04.010
日期:2013.6
preparation of a newfamily of enantiopure mono-N-tosylated-1,2-diamines derived from (R)-(+)-limonene is described. (+)-Limonene was transformed into the appropriate N-tosyl derivative using N-tosylaziridination based on chloramine-T trihydrate. Subsequent ring opening by sodium azide afforded the corresponding isomeric azides. Finally, reduction of the azide function gave enantiomerically pure mono-N-tosylated-1
The first highly enantioselective iridium-catalyzed hydrogenation of cyclicenamines has been developed. This new reaction provided an efficient method for the synthesis of optically active cyclic tertiary amines including natural product crispine A.
A Highly Enantioselective Access to Tetrahydroisoquinoline and β-Carboline Alkaloids with Simple Noyori-Type Catalysts in Aqueous Media
作者:Laurent Evanno、Joel Ormala、Petriâ M. Pihko
DOI:10.1002/chem.200902289
日期:2009.12.7
enhancement: A very convenient modified protocol for the enantioselective transfer hydrogenation of dihydroisoquinoline skeletons under aqueous conditions is reported. Unmodified Noyori ligands can be used and the activity of the catalyst is greatly enhanced with silver additives (see scheme). The protocol was used in a very short synthesis of the alkaloids (S)‐harmicine and (S)‐crispine.
Facile two-step synthesis of crispine A and harmicine by cyclopropylimine rearrangement
作者:Sanjay Saha、Ch. Venkata Ramana Reddy、Balaram Patro
DOI:10.1016/j.tetlet.2011.05.117
日期:2011.8
The synthesis of 4 and 8 is reported. These intermediates are obtained by a one-pot tandem cyclization of 1 and 6, respectively, via BischlerNapieralski reaction followed by cyclopropylimine rearrangement. Compounds 4 and 8 were reduced by sodium borohydride in methanol to afford cytotoxic alkaloid (±)-crispine A and antileishmania compound (±)-harmicine.
Asymmetric Synthesis of Fused-Ring Tetrahydroisoquinolines and Tetrahydro-β-carbolines from 2-Arylethylamines via a Chemoenzymatic Approach
作者:Linsong Yang、Jianjiong Li、Zefei Xu、Peiyuan Yao、Qiaqing Wu、Dunming Zhu、Yanhe Ma
DOI:10.1021/acs.orglett.2c02466
日期:2022.9.16
While chiral fused-ring tetrahydroisoquinoline (THIQ) and tetrahydro-β-carboline (THβC) scaffolds have attracted considerable interest due to their wide spectrum of biological activities, the synthesis of optically pure chiral fused-ring THIQs and THβCs remains a challenging task. Herein, a group of active imine reductases were identified to convert the imine precursors into the corresponding enantiocomplementary