Tags

Type your tag names separated by a space and hit enter

Lewis base activation of Lewis acids: catalytic, enantioselective addition of glycolate-derived silyl ketene acetals to aldehydes.
J Org Chem. 2008 Jun 20; 73(12):4582-95.JO

Abstract

A catalytic system involving silicon tetrachloride and a chiral, Lewis basic bisphosphoramide catalyst is effective for the addition of glycolate-derived silyl ketene acetals to aldehydes. It was found that the sense of diastereoselectivity could be modulated by changing the size of the substituents on the silyl ketene acetals. In general, the trimethylsilyl ketene acetals derived from methyl glycolates with a large protecting group on the alpha-oxygen provide enantiomerically enriched alpha,beta-dihydroxy esters with high syn-diastereoselectivity, whereas the tert-butyldimethylsilyl ketene acetals derived from bulky esters of alpha-methoxyacetic acid provide enantiomerically enriched alpha,beta-dihydroxy esters with high anti-diastereoselecitvity.

Links

Publisher Full Text (DOI)

Authors+Show Affiliations

Denmark SE
Department of Chemistry, Roger Adams Laboratory, University of Illinois, Urbana, IL 61801, USA. denmark@scs.uiuc.edu
Chung WJ
No affiliation info available

MeSH

AcetalsAcidsAldehydesAlkaliesCatalysisGlycolatesStereoisomerism

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

18505296

Citation

Denmark, Scott E., and Won-Jin Chung. "Lewis Base Activation of Lewis Acids: Catalytic, Enantioselective Addition of Glycolate-derived Silyl Ketene Acetals to Aldehydes." The Journal of Organic Chemistry, vol. 73, no. 12, 2008, pp. 4582-95.
Denmark SE, Chung WJ. Lewis base activation of Lewis acids: catalytic, enantioselective addition of glycolate-derived silyl ketene acetals to aldehydes. J Org Chem. 2008;73(12):4582-95.
Denmark, S. E., & Chung, W. J. (2008). Lewis base activation of Lewis acids: catalytic, enantioselective addition of glycolate-derived silyl ketene acetals to aldehydes. The Journal of Organic Chemistry, 73(12), 4582-95. https://doi.org/10.1021/jo8006539
Denmark SE, Chung WJ. Lewis Base Activation of Lewis Acids: Catalytic, Enantioselective Addition of Glycolate-derived Silyl Ketene Acetals to Aldehydes. J Org Chem. 2008 Jun 20;73(12):4582-95. PubMed PMID: 18505296.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Lewis base activation of Lewis acids: catalytic, enantioselective addition of glycolate-derived silyl ketene acetals to aldehydes. AU - Denmark,Scott E, AU - Chung,Won-Jin, Y1 - 2008/05/28/ PY - 2008/5/29/pubmed PY - 2008/8/6/medline PY - 2008/5/29/entrez SP - 4582 EP - 95 JF - The Journal of organic chemistry JO - J Org Chem VL - 73 IS - 12 N2 - A catalytic system involving silicon tetrachloride and a chiral, Lewis basic bisphosphoramide catalyst is effective for the addition of glycolate-derived silyl ketene acetals to aldehydes. It was found that the sense of diastereoselectivity could be modulated by changing the size of the substituents on the silyl ketene acetals. In general, the trimethylsilyl ketene acetals derived from methyl glycolates with a large protecting group on the alpha-oxygen provide enantiomerically enriched alpha,beta-dihydroxy esters with high syn-diastereoselectivity, whereas the tert-butyldimethylsilyl ketene acetals derived from bulky esters of alpha-methoxyacetic acid provide enantiomerically enriched alpha,beta-dihydroxy esters with high anti-diastereoselecitvity. SN - 0022-3263 UR - https://www.unboundmedicine.com/medline/citation/18505296/Lewis_base_activation_of_Lewis_acids:_catalytic_enantioselective_addition_of_glycolate_derived_silyl_ketene_acetals_to_aldehydes_ L2 - https://doi.org/10.1021/jo8006539 DB - PRIME DP - Unbound Medicine ER -