Trifluoromethyl Ketimines Research Articles

Efficient preparation of Ellman’s imines from trifluoromethyl ketones promoted by zirconium(IV) tert-butoxide

An efficient synthesis of chiral N-tert-butanesulfinyl trifluoromethyl ketimines by using zirconium(IV) tert-butoxide is described. Compared to conventional titanium(IV) ethoxide, this protocol gave better result especially for sterically hindered ketones. In addition to the high reactivity, a high degree of enantiopurity of the N-tert-butanesulfinyl group is retained.

Highly Enantioselective Decarboxylative Mannich Reaction of Malonic Acid Half Oxyesters with Cyclic Trifluoromethyl Ketimines: Synthesis of β‐Amino Esters and Anti‐HIV Drug DPC 083

An organocatalytic enantioselective decarboxylative Mannich reaction of malonic acid half oxyesters with cyclic ketimines was developed for the preparation of enantioenriched β-amino esters with a quaternary stereogenic center and the anti-HIV drug DPC 083 (see scheme).

An efficient synthesis of optically active trifluoromethyl aldimines via asymmetric biomimetic transamination

This communication describes a chiral base-catalyzed asymmetric [1,3]-proton shift of trifluoromethyl ketimines, giving a wide variety of trifluoromethyl aldimines containing various functional groups with up to 94% ee.

Thermocontrolled benzylimine–benzaldimine rearrangement over Nafion-H catalysts for efficient entry into α-trifluoromethylbenzylamines

Nafion-H and Nafion SAC-13 are efficient solid Brønsted acid catalysts for the preparation of trifluoromethyl ketimines from benzylamines and trifluoromethylated ketones in high yields. A finely tuned benzylimine–benzaldimine rearrangement by facile 1,3-hydrogen shift has been achieved for the formation of fluorinated benzaldimines in high yields by careful optimization of reaction conditions including attempts under microwave conditions and a flow system. These α-trifluoromethylated benzaldimines are efficient precursors for pharmaceutically important α-trifluoromethylated benzylamines, accessed through their direct acid hydrolysis.

Bifunctional Cinchona Alkaloid Thiourea Catalyzed Highly Efficient, Enantioselective Aza‐Henry Reaction of Cyclic Trifluoromethyl Ketimines: Synthesis of Anti‐HIV Drug DPC 083

Highly efficient: The title reaction provides biologically interesting chiral trifluoromethyl dihydroquinazolinone frameworks in high yields (up to 97 %) and with high enantioselectivities (up to 98 % ee), using as low as 1 mol % of catalyst (see scheme). Moreover, anti-HIV drug candidate DPC 083 was efficiently synthesized using the highly enantioselective aza-Henry reaction as a key step. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Bifunctional Cinchona Alkaloid Thiourea Catalyzed Highly Efficient, Enantioselective Aza‐Henry Reaction of Cyclic Trifluoromethyl Ketimines: Synthesis of Anti‐HIV Drug DPC 083

Biologisch interessante chirale Trifluormethyldihydrochinazolinon-Gerüste werden durch die Titelreaktion mit nur 1 Mol-% Katalysator in hohen Ausbeuten (bis 97 %) und mit hohen Enantioselektivitäten (bis 98 % ee) aufgebaut. Eine effiziente Synthese des potenziellen Anti-HIV-Wirkstoffs DPC 083 nutzte diese hoch enantioselektive Aza-Henry-Reaktion als Schlüsselschritt.

Organocatalytic Enantioselective Strecker Synthesis of α‐Quaternary α‐Trifluoromethyl Amino Acids

AbstractThe first organocatalytic enantioselective Strecker synthesis of α‐quaternary α‐trifluoromethylated amino acids has been developed. Employing Takemoto’s thiourea catalyst the nucleophilic addition of trimethylsilyl cyanide to trifluoromethyl ketimines affords α‐amino nitriles in good to excellent yields (50–99%) and very good enantioselectivities (ee=83–95%). The enantiopure amino nitriles can be obtained by recrystallization. Deprotection and hydrolysis leads to the title amino acids.

Solvent-Free Stereoselective Synthesis of (E)-Trifluoromethyl Imines and Hydrazones

A new, green and efficient strategy for the synthesis of trifluoromethyl ketimines, aldimines, and hydrazones starting from the corresponding trifluoromethyl carbonyl compounds or their hemiacetals is reported. The condensation reactions were performed under solvent-free conditions with a range of amines or hydrazines and proceeded with high stereoselectivity, always giving only the E-isomer in very good yields.

ChemInform Abstract: N‐Heterocyclic Carbene Catalyzed Nucleophilic Acylation of Trifluoromethyl Ketimines.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

N-Heterocyclic Carbene Catalyzed Nucleophilic Acylation of Trifluoromethyl Ketimines

An efficient N-heterocyclic carbene (NHC)-catalyzed nucleophilic acylation of trifluoromethyl ketimines has been developed. The combination of N-aryl trifluoromethyl ketimines with various furan-2-carbaldehydes leads chemoselectively to the corresponding α-amino-a-trifluoromethyl ketones in moderate to very good yields (32-87%) providing ready access to this pharmaceutically important class of compounds.

Convenient enantioselective synthesis of β-trifluoromethyl-β-aminoketones by organocatalytic asymmetric Mannich reaction of aryl trifluoromethyl ketimines with acetone

The l-proline-catalyzed asymmetric Mannich reaction has been performed between aryl trifluoromethyl ketimines and acetone to provide, for the first time, chiral β-aryl-β-trifluoromethyl-β-aminoketones in high yields and with 74–92% enantiomeric excesses.

Catalytic Asymmetric Synthesis of α,α,α-Trifluoromethylamines by the Copper-Catalyzed Nucleophilic Addition of Diorganozinc Reagents to Imines

[reaction: see text] A copper-catalyzed asymmetric addition of diorganozinc reagents to N-phosphinoylimines has been developed for the synthesis of chiral alpha,alpha,alpha-trifluoromethylamines. The trifluoromethyl ketimines, generated in situ from the corresponding hemiaminals, led to the chiral amides in high yields (71-89%) and excellent enantiocontrol (91-99% ee).

Trifluoroacetimidoyl chlorides as a new trifluoromethyl building block for fluorinated nitrogen heterocycles

N-Substituted trifluoroacetimidoyl chlorides have been prepared and allowed to react with various carbon nucleophiles, fording trifluoromethyl ketimines.