Candida antarctica lipase B catalysed kinetic resolution of 1,2,3,4-tetrahydro-beta-carbolines: Substrate specificity

• Published in: Tetrahedron
• Main Authors: Kovács Barbara, Forró Enikő, Fülöp Ferenc
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: Antarc*; Antarctica
• Online Access: http://publicatio.bibl.u-szeged.hu/14935/; http://publicatio.bibl.u-szeged.hu/14935/1/BarbaraTetrah2018.pdf; https://doi.org/10.1016/j.tet.2018.10.034

In the frame of substrate specificity, CAL-B-catalysed asymmetric N-alkoxycarbonylations of 1-substituted tetrahydro-beta-carbolines (Me, Et, Pr, iPr) have been studied. High enantioselectivities (>200) were observed, when alkoxycarbonylation of racemic compounds (+/-)-1,35,7 were performed in DIPE in the presence of phenyl allyl carbonate and Et3N at 60 degrees C using ultrasound shaking method. The reaction time increased considerably with increasing substituent size on C1; however, the isopropyl-substituted compound proved to be too bulky for the optimum activity of CAL-B. The (R)-carbamate enantiomers were hydrolysed using Pd-2(dba)(3 center dot)CHCI3 and the enantiomers of the free amines were obtained with excellent ee (>99%). (C) 2018 Published by Elsevier Ltd.