A Biocatalytic Route to Highly Enantioenriched β-Hydroxydioxinones
作者:Rick C. Betori、Eric R. Miller、Karl A. Scheidt
DOI:10.1002/adsc.201700095
日期:2017.4.3
A novel biocatalytic system to access a wide variety of β‐hydroxydioxinones from β‐ketodioxinones employing commercial engineered ketoreductases has been developed. This practical system provides a remarkably straightforward solution to limitations in accessing certain chemical scaffolds common in β‐hydroxydioxinones that are of great interest due to their diversification capabilities. A few highlights
Lewis Base Activation of Lewis Acids. Vinylogous Aldol Reactions
作者:Scott E. Denmark、Gregory L. Beutner
DOI:10.1021/ja035448p
日期:2003.7.1
A highly regioselective vinylogous aldol reaction catalyzed by SiCl4 and a chiral phosphoramide (R,R)-5, providing delta-hydroxy enones for a variety of aldehyde and dienol ether structures, has been developed. Low catalyst loadings (1 mol %) can be employed, giving the products in good yields, excellent enantioselectivities, and in some cases excellent anti diastereoselectivities. Both simple ester-derived
A convenient catalytic procedure for the highly enantioselective aldol condensation of O-silyldienolates
作者:Margherita De Rosa、Maria Rosaria Acocella、Rosaria Villano、Annunziata Soriente、Arrigo Scettri
DOI:10.1016/s0957-4166(03)00494-4
日期:2003.9
In the presence of catalytic amount of chiral Ti(OiPr)(4)/BINOL (0.08 equiv.) the asymmetric aldol condensation of 6-methyl-4H-[1,3]-dioxin-4-one-derived silyloxydienes takes place in high yields and enantiomeric excesses with aromatic. heteroaromatic, Unsaturated and aliphatic aldehydes. Notable amplification of enantiomeric excesses have been obtained by using enantioenriched catalytic systems. (C) 2003 Elsevier Ltd. All rights reserved.
Catalytic, Enantioselective Dienolate Additions to Aldehydes: Preparation of Optically Active Acetoacetate Aldol Adducts