vinylogous aldol reaction of activated allyls to activated acyclic ketones is disclosed. A variety of activated acyclic ketones, such as trifluoromethyl ketones, α-ketoesters, and α-keto phosphonates, were found to be involved forming diverse γ-selective aldoladducts with high enantioselectivities (up to >99% ee). The method provides an effective, general strategy to access valuable chiral electron-withdrawing
Catalytic enantioselective alkenylation and phenylation of trifluoromethyl ketones are described. High enantioselectivity (up to 84% ee) was produced in an alkenylation of aryl trifluoromethyl ketones using a CuF–DTBM-SEGPHOS complex as the catalyst (5–10 mol %) and alkenylsilanes as the nucleophile. This is the first example of catalytic enantioselective alkenylation of trifluoromethyl ketones. The
Asymmetric cross-aldol reactions of α-keto hydrazones and α,β-unsaturated γ-keto hydrazones with trifluoromethyl ketones
作者:Saúl Alberca、Esteban Matador、Javier Iglesias-Sigüenza、Ma de Gracia Retamosa、Rosario Fernández、José M. Lassaletta、David Monge
DOI:10.1039/d1cc05014a
日期:——
α-Keto hydrazones and α,β-unsaturated γ-keto hydrazones are suitable pro-nucleophiles for asymmetric cross-aldol reactions with trifluoromethyl ketones via aza-di(tri)enamine-type intermediates. A quinidine-derived primary amine catalyst affords tertiary trifluoromethylated alcohols in good-to-excellent yields and high enantioselectivities. Subsequent transformations of hydrazono moieties yield appealing