Title of article
Catalytic asymmetric hydrogenation of heterocyclic ketone-derived hydrazones, pronounced solvent effect on the inversion of configuration
Author/Authors
Haddad، نويسنده , , Nizar and Qu، نويسنده , , Bo and Rodriguez، نويسنده , , Sonia and van der Veen، نويسنده , , Lars and Reeves، نويسنده , , Diana C. and Gonnella، نويسنده , , Nina C. and Lee، نويسنده , , Heewon and Grinberg، نويسنده , , Nelu and Ma، نويسنده , , Shengli and Krishnamurthy، نويسنده , , Dhileepkumar and Wunberg، نويسنده , , Tobias and Senanayake، نويسنده , , Chris H.، نويسنده ,
Issue Information
هفته نامه با شماره پیاپی سال 2011
Pages
5
From page
3718
To page
3722
Abstract
An enantioselective hydrogenation of hydrazones derived from heterocyclic ketones was developed with up to 85% ee. The enantiomeric purity was enriched to >99% ee by crystallization from EtOAc in >80% yield. Optimization studies have revealed a notable solvent effect that resulted in inversion of enantioselectivity from 85% ee in MeOH to −27% ee in DCE. The hydrazone geometry and possible hydrogenation via endocyclic alkene were examined as possible factors for the inversion of enantioselectivity.
Keywords
Chiral hydrazenes , Hydrazones , asymmetric hydrogenation , Reversed enantioselectivity
Journal title
Tetrahedron Letters
Serial Year
2011
Journal title
Tetrahedron Letters
Record number
1878764
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