Novel chiral proline-based organocatalysts with amide and thiourea–amine units for highly efficient asymmetric aldol reaction in saturated brine without additives
Keyword(s):
A series of novel proline-based organocatalysts with amide and thiourea-amine units (7a–7f) were developed and evaluated in the asymmetric aldol reaction of 4-nitrobenzaldehyde with cyclohexanone. The organocatalyst (7c or 7d, 5 mol%) exhibited efficient catalytic activity to afford aldol products in high diastereoselectivity (up to >99:1), enantioselectivity (up to >99%), and yield (up to >96%) at 0 °C in saturated brine without adding an acid. Aldol products of benzaldehyde derivatives almost universally provide high diastereoselectivity and enantioselectivity.
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2009 ◽
Vol 351
(1-2)
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pp. 276-282
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2012 ◽
Vol 10
(11)
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pp. 2209
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Keyword(s):
2009 ◽
Vol 20
(12)
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pp. 1419-1424
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Keyword(s):