Search results for "TRIF"

ChemInform Abstract: Highly Enantioselective Copper(I)-Catalyzed Conjugate Addition of Terminal Alkynes to 1,1-Difluoro-1-(phenylsulfonyl)-3-en-2-one…

2014

A highly enantioselective copper-catalyzed conjugate alkynylation of monoactivated enones, namely 1,1-difluoro-1-(phenylsulfonyl)-3-en-2-ones, is described. The reaction products are obtained with good yields and excellent enantioselectivities (from 92 to 99% ee). The β-alkynylated difluoro(phenylsulfonyl) ketones can be converted into the corresponding β-alkynylated difluoro- and trifluoromethyl ketones, esters and amides. This is the first example on the use of 1,1-difluoro-1-(phenylsulfonyl)-3-en-2-ones as substrates in an enantioselective reaction, which have been shown to be new ester/amide surrogates.

Synthesis of trifluoromethyl-substituted 1,2,6-thiadiazine 1-oxides from sulfonimidamides under mechanochemical conditions

2021

TBS-protected or NH-sulfonimidamides react with β-alkoxyvinyl trifluoromethylketones under solvent-free mechanochemical conditions to give 3-trifluoromethyl-substituted three-dimensional 1,2,6-thiadiazine 1-oxides. C4-Functionalized products can be obtained by starting from cyclic enones and brominations of the initially formed heterocycles. The stability of the products was investigated by varying the pH value and storage under aerobic conditions.

On the Reactivity of C(sp3)–H σ-Bonds: Oxygenation with Methyl(trifluoromethyl)­dioxirane

2008

The reactivity of C–H σ-bonds of a series of 2-substituted adamantanes 2 towards methyl(trifluoromethyl)dioxirane (1) shows a consistent dependence on the electron-withdrawing ability, either inductive or by resonance, of the substituent. The results are interpreted in terms of the ability of the substrate molecule to delocalize the electronic perturbation of the reacting center at the beginning of the reaction path. The model shows that the electronic demand from the reacting C–H σ-bond is transmitted along the substrate through a chain of hyperconjugative interactions, the relative intensities of which depend on the σ-bonds involved. The substrate molecule simultaneously provides positive…

An efficient entry to optically active anti- and syn-beta-amino-alpha-trifluoromethyl alcohols.

2008

The reaction of chiral 5,6-dihydro-2H-1,4-oxazin-2-ones with TMSCF3 in the presence of a suitable activator leads to trifluoromethyl lactols, which can be selectively reduced to anti-beta-amino-alpha-trifluoromethyl alcohols. The corresponding syn diastereoisomers are obtained when the starting imines are reduced and the nitrogen atom is conveniently protected. In addition, a novel rearrangement of the CF3 group in the lactol intermediates has been observed. This represents a formal CF3 addition to the imine function in the starting substrates.

ChemInform Abstract: Catalytic Enantioselective Conjugate Alkynylation of α,β-Unsaturated 1,1,1-Trifluoromethyl Ketones with Terminal Alkynes.

2016

Financial support (Grant CTQ2013-47494-P) from the Ministerio de Economia y Competitividad (MINECO-Gobierno de Espana). A.S.M. thanks the MINECO for a predoctoral grant (FPI program). Access to NMR and MS facilities from the Servei Central de Suport a la Investigacio Experimental (SCSIE)-UV is also acknowledged.

ChemInform Abstract: Catalytic Asymmetric Conjugate Addition of Terminal Alkynes to β-Trifluoromethyl α,β-Enones.

2014

The first enantioselective conjugate alkynylation of β-trifluoromethyl α,β-enones (II) using terminal alkynes (I) and a taniaphos-Cu(I) complex as catalyst is described.

Theoretical Study of the 1,3-Dipolar Cycloaddition Reactions of Azomethine Ylides. A DFT Study of Reaction between Trifluoromethyl Thiomethyl Azometh…

1999

The molecular mechanism for the 1,3-dipolar cycloaddition of trifluoromethyl thiomethyl azomethine ylide with acronitrile has been characterized using density functional theory methods with the B3L...

ChemInform Abstract: Enantioselective Zirconium-Catalyzed Friedel-Crafts Alkylation of Pyrrole with Trifluoromethyl Ketones.

2009

The first catalytic enantioselective Friedel−Crafts alkylation of pyrrole with 2,2,2-trifluoroacetophenones to give pyrroles with a trifluoromethyl-substituted tertiary alcohol moiety bearing a quaternary stereogenic center is described. The reaction is achieved in the presence of a 3,3′-dibromo-BINOL-Zr(IV) complex to give the expected products with high yields (up to 98%) and good enantioselectivities (up to 93% ee). The absolute stereochemistry of the products has been determined by chemical correlation.

Understanding the Influence of the Trifluoromethyl Group on the Selectivities of the [3+2] Cycloadditions of Thiocarbonyl S ‐methanides with α,β‐Unsa…

2020

ChemInform Abstract: Approaches for the Introduction of Fluorinated Substituents into [1,2,3]Triazolo[1,5-a]pyridines.

2014

Functionalization of [1,2,3]triazolo[1,5-a]pyridines with a trifluoromethyl group is achieved for the first time.