Highly diastereoselective synthesis of trifluoromethyl containing spiro[pyrrolidin-3,2′-oxindoles] from N-2,2,2-trifluoroethylsubstituted isatin imines and β,γ-unsaturated α-keto esters
Sign Up to like & getrecommendations! Published in 2021 at "Tetrahedron"
DOI: 10.1016/j.tet.2021.132112
Abstract: ABSTRACT Inspired by the chemistry and biology of fluorine-containing molecules and pyrrolidinyl spirooxindoles, herein we report a highly diastereoselective [3+2] cycloaddition reaction of β,γ-unsaturated α-keto esters and N-2,2,2-trifluoroethylisatin ketimines in the presence of the catalyst… read more here.
Keywords: spiro pyrrolidin; highly diastereoselective; keto esters; pyrrolidin oxindoles ... See more keywords
Asymmetric cross-aldol reactions of α-keto hydrazones and α,β-unsaturated γ-keto hydrazones with trifluoromethyl ketones.
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DOI: 10.1039/d1cc05014a
Abstract: 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… read more here.
Keywords: asymmetric cross; keto hydrazones; keto; cross aldol ... See more keywords
Direct Synthesis of β,γ-Unsaturated α-Keto Esters from Aldehydes and Pyruvates
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DOI: 10.1055/s-0037-1612255
Abstract: Herein, we describe two practical methods to synthesize β,γ-unsaturated α-keto esters directly from aldehydes and pyruvates promoted by BF3•Et2O in the presence of Ac2O or by Ti(OEt)4 under mild conditions. A variety of aromatic aldehydes… read more here.
Keywords: synthesis unsaturated; aldehydes pyruvates; unsaturated keto; keto esters ... See more keywords
Catalytic Asymmetric Domino Michael/Annulation Reaction of Bifunctional Chromone Synthons with β,γ-Unsaturated α-Keto Esters: Rapid Access to Polysubstituted Spirocyclic Hexahydroxanthones
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DOI: 10.1055/s-0040-1707340
Abstract: A thiourea-catalyzed asymmetric domino Michael/annulation process was devised employing bifunctional oxindole-chromones as C4 synthons and β,γ-unsaturated α-keto esters as C2 synthons. This reaction enables the highly diastereo- and enantioselective synthesis of a range of biologically… read more here.
Keywords: asymmetric domino; keto esters; domino michael; michael annulation ... See more keywords