Stereoselective aldol reactions of dihydroxyacetone derivatives catalyzed by chiral Zn2+ complexes
The direct aldol reaction between a protected dihydroxyacetone derivative and 4-nitrobenzaldehyde catalyzed by chiral Zn2+ complexes of 1-(n-carboxylalkyl)-7-aminoacyl-1,4,7,10-tetraazacyclododecane is reported. New Zn2+ complexes containing l-histidine and carboxylalkyl chains that mimic a class II...
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Published in | Tetrahedron Vol. 75; no. 6; pp. 757 - 777 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
OXFORD
Elsevier Ltd
08.02.2019
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | The direct aldol reaction between a protected dihydroxyacetone derivative and 4-nitrobenzaldehyde catalyzed by chiral Zn2+ complexes of 1-(n-carboxylalkyl)-7-aminoacyl-1,4,7,10-tetraazacyclododecane is reported. New Zn2+ complexes containing l-histidine and carboxylalkyl chains that mimic a class II aldolase, carboxypeptidase A and a serine protease were designed and synthesized. Syn-aldol products were mainly formed by an aldol reaction of acetonide-protected dihydroxyacetone with benzaldehydes and other benzaldehydes in N-methylpyrrolidone (NMP)/alcohol (MeOH, EtOH or 2-PrOH) in good yields with a high degree of diastereo- and enantioselectivity (56%∼quant., 57∼>99% ee). Mechanistic aspect based on ESI-HRMS, elemental analysis and pH titrations of model ligands is also discussed.
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ISSN: | 0040-4020 1464-5416 |
DOI: | 10.1016/j.tet.2018.12.060 |