Enantioselective reduction of isatin derivatives over cinchonidine modified Pt/alumina

Sonderegger, Otmar J.; Buergi, Thomas; Limbach, Ludwig K.; Baiker, Alfons

doi:10.1016/j.molcata.2004.02.018

Scientific article

English

Enantioselective reduction of isatin derivatives over cinchonidine modified Pt/alumina

Contributors

Sonderegger, Otmar J.; Buergi, Thomas; Limbach, Ludwig K.; Baiker, Alfons

Published in

Journal of molecular catalysis. A, Chemical, vol. 217, no. 1-2, p. 93-101

Publication date

2004

Abstract

The enantioselective hydrogenation of several isatine derivatives over cinchonidine modified Pt/Al2O3 was investigated. A maximum enantiomeric excess (e.e.) of 45% was found for (R)-5,7-dimethylisatin. The enantiomeric excess was limited by racemization catalyzed by the basic cinchonidine in solution, leading to low enantiomeric excess at high cinchonidine concentration. The modifier in solution also catalyzed the formation of the corresponding isatide. High cinchonidine concentration favored isatide formation, whereas low cinchonidine concentration and high hydrogen pressure favored alcohol formation. The isatide, formed from the isatin reactant and the alcohol, underwent disproportionation. Though both hydrogenation and isatide formation are fast reactions, isatide formation was considerably faster at least at the beginning of the reaction. Substitution of the isatin reactant had relatively little effect on enantiomeric excess but affected considerably the rate of racemization.

UNIGE affiliation entities

Faculté des sciences / Section de chimie et biochimie / Département de chimie physique

Citation (ISO format)

SONDEREGGER, Otmar J. et al. Enantioselective reduction of isatin derivatives over cinchonidine modified Pt/alumina. In: Journal of molecular catalysis. A, Chemical, 2004, vol. 217, n° 1-2, p. 93–101. doi: 10.1016/j.molcata.2004.02.018

Article

Identifiers

PID : unige:14724
DOI : 10.1016/j.molcata.2004.02.018

Additional URL for this publication

http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TGM-4C4BN8H-1-17&_cdi=5258&_user=9565874&_pii=S1381116904001281&_origin=search&_coverDate=08%2F03%2F2004&_sk=997829998&view=c&wchp=dGLzVtz-zSkzS&md5=7982aed5cdb45415050988d5fe04e7a5&ie=/sdarticle.pdf

Journal ISSN

1381-1169

806views

0downloads

Creation

18/03/2011 13:57:11

First validation

18/03/2011 13:57:11

Update

14/03/2023 16:14:01

Status update

14/03/2023 16:14:01

Last indexation

29/10/2024 17:56:53

Enantioselective reduction of isatin derivatives over cinchonidine modified Pt/alumina

Contributors

Published in

Publication date

Abstract

UNIGE affiliation entities

Citation (ISO format)

Main files (1)

Identifiers

Additional URL for this publication

Journal ISSN

Technical informations

Creation

First validation

Update

Status update

Last indexation