Effect of substituents on enantioselectivity in chiral oxazaborolidine mediated asymmetric ketone reduction reaction
IR@NISCAIR: CSIR-NISCAIR, New Delhi - ONLINE PERIODICALS REPOSITORY (NOPR)
View Archive Info| Field | Value | |
| Title |
Effect of substituents on enantioselectivity in chiral oxazaborolidine mediated asymmetric ketone reduction reaction
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| Creator |
Balakrishnan, U
Ananthi, N Velmathi, S |
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| Subject |
L-Valine
Prochiral ketone reduction Oxazaborolidine Chiral amines Asymmetric synthesis |
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| Description |
1157-1164
Various new chiral ligands have been synthesized by the condensation of different esters of l-Valine with different substituted salicylaldehydes in order to find the most effective catalyst for the enantioselctive ketone reduction. Chiral amine synthesized from l-Valine methyl ester and 5-chloro salicylaldehyde is found to catalyse the enantioselective reduction of prochiral ketone with high yield (99%) and enantiomeric excess (91%) with 20 mol% of the catalyst using borane dimethylsulphide as a stoichiometric reducutant. Different subsituted prochiral ketones have also been reduced in high yield upto 90% and the corresponding secondary alcohols are formed with good enantiomeric excess upto 99%. The mechanism of this reduction can be very well explained by considering a plausible mechanism for the CBS catalyst. |
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| Date |
2011-09-07T08:40:20Z
2011-09-07T08:40:20Z 2011-09 |
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| Type |
Article
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| Identifier |
0975-0983(Online); 0376-4699(Print)
http://hdl.handle.net/123456789/12665 |
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| Language |
en_US
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| Rights |
<img src='http://nopr.niscair.res.in/image/cc-license-sml.png'> <a href='http://creativecommons.org/licenses/by-nc-nd/2.5/in' target='_blank'>CC Attribution-Noncommercial-No Derivative Works 2.5 India</a>
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| Publisher |
NISCAIR-CSIR, India
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| Source |
IJC-B Vol.50B(09) [September 2011]
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