Lewis base activation of Lewis acids. Vinylogous aldol addition reactions of conjugated N,O-silyl ketene acetals to aldehydes.
J Am Chem Soc. 2006 Feb 01; 128(4):1038-9.JA

Abstract

N,O-Silyl dienyl ketene acetals derived from unsaturated morpholine amides have been developed as highly useful reagents for vinylogous aldol addition reactions. In the presence of SiCl4 and the catalytic action of chiral phosphoramide (R,R)-3, N,O-silyl dienyl ketene acetal 8 undergoes high-yielding and highly site-selective addition to a wide variety of aldehydes with excellent enantioselectivity. Of particular note is the high yields and selectivities obtained from aliphatic aldehydes. Low catalyst loadings (2-5 mol %) can be employed. The morpholine amide serves as a useful precursor for further synthetic manipulation.

Authors+Show Affiliations

Denmark SE

Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, 61801, USA. denmark@scs.uiuc.edu

Heemstra JR

No affiliation info available

MeSH

AcetalsAldehydesEthylenesKetonesSilanesVinyl Compounds

Pub Type(s)

Journal Article

Research Support, Non-U.S. Gov't

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

Language

eng

PubMed ID

16433495

Citation

Denmark, Scott E., and John R. Heemstra. "Lewis Base Activation of Lewis Acids. Vinylogous Aldol Addition Reactions of Conjugated N,O-silyl Ketene Acetals to Aldehydes." Journal of the American Chemical Society, vol. 128, no. 4, 2006, pp. 1038-9.

Denmark SE, Heemstra JR. Lewis base activation of Lewis acids. Vinylogous aldol addition reactions of conjugated N,O-silyl ketene acetals to aldehydes. J Am Chem Soc. 2006;128(4):1038-9.

Denmark, S. E., & Heemstra, J. R. (2006). Lewis base activation of Lewis acids. Vinylogous aldol addition reactions of conjugated N,O-silyl ketene acetals to aldehydes. Journal of the American Chemical Society, 128(4), 1038-9.

Denmark SE, Heemstra JR. Lewis Base Activation of Lewis Acids. Vinylogous Aldol Addition Reactions of Conjugated N,O-silyl Ketene Acetals to Aldehydes. J Am Chem Soc. 2006 Feb 1;128(4):1038-9. PubMed PMID: 16433495.

* Article titles in AMA citation format should be in sentence-case

TY - JOUR T1 - Lewis base activation of Lewis acids. Vinylogous aldol addition reactions of conjugated N,O-silyl ketene acetals to aldehydes. AU - Denmark,Scott E, AU - Heemstra,John R,Jr PY - 2006/1/26/pubmed PY - 2006/4/14/medline PY - 2006/1/26/entrez SP - 1038 EP - 9 JF - Journal of the American Chemical Society JO - J Am Chem Soc VL - 128 IS - 4 N2 - N,O-Silyl dienyl ketene acetals derived from unsaturated morpholine amides have been developed as highly useful reagents for vinylogous aldol addition reactions. In the presence of SiCl4 and the catalytic action of chiral phosphoramide (R,R)-3, N,O-silyl dienyl ketene acetal 8 undergoes high-yielding and highly site-selective addition to a wide variety of aldehydes with excellent enantioselectivity. Of particular note is the high yields and selectivities obtained from aliphatic aldehydes. Low catalyst loadings (2-5 mol %) can be employed. The morpholine amide serves as a useful precursor for further synthetic manipulation. SN - 0002-7863 UR - https://www.unboundmedicine.com/medline/citation/16433495/Lewis_base_activation_of_Lewis_acids__Vinylogous_aldol_addition_reactions_of_conjugated_NO_silyl_ketene_acetals_to_aldehydes_ DB - PRIME DP - Unbound Medicine ER -

Tags

Lewis base activation of Lewis acids. Vinylogous aldol addition reactions of conjugated N,O-silyl ketene acetals to aldehydes.J Am Chem Soc. 2006 Feb 01; 128(4):1038-9.JA