Tetrabutylammonium Bromide-Catalyzed Transfer Hydrogenation of Quinoxaline with HBpin as a Hydrogen Source

2021 ◽  
Author(s):  
Qi Guo ◽  
Jingchao Chen ◽  
Guoli Shen ◽  
Guangfu Lu ◽  
Xuemei Yang ◽  
...  
Keyword(s):  
Tetrabutylammonium Bromide ◽  
Transfer Hydrogenation

Use of Nafion membranes in laboratory organic electrosynthesis

1988 ◽  
Vol 53 (12) ◽  
pp. 3164-3170 ◽  
Author(s):  
Jaromír Hlavatý ◽  
Jiří Volke
Keyword(s):  
Glassy Carbon ◽  
Quaternary Ammonium ◽  
Tetrabutylammonium Bromide ◽  
Nafion Membrane ◽  
Carbon Anode ◽  
Tetrabutylammonium Hydroxide ◽  
Nafion Membranes ◽  
Divided Cell ◽  
A Cell ◽  
Tetrabutylammonium Iodide

Electrolysis of quaternary ammonium bromides and iodides in a divided cell with a Nafion membrane yields quaternary polyhalogenides at a carbon anode in water-ethanolic anolytes. The electrodialysis of tetrabutylammonium iodide in a cell with a Nafion membrane enables generation of tetrabutylammonium hydroxide. In electrolytic reduction of nitrobenzene in presence of 1,3-dibromopropane, N-phenylisooxazolidine results in an approx. 60% yield. This electrosynthesis takes place in dimethylformamide with tetrabutylammonium bromide at a glassy-carbon cathode in a divided cell. In the electroreduction of lobelanine hydrogensulfate in a divided cell in acid water-ethanolic media at a lead cathode prevalently lobelanidine has been obtained.

Mild and Selective Rhodium-Catalyzed Transfer Hydrogenation of Functionalized Arenes

2021 ◽  
Vol 23 (5) ◽  
pp. 1910-1914
Author(s):  
Yuhan Wang ◽  
Zhiqian Chang ◽  
Yan Hu ◽  
Xiao Lin ◽  
Xiaowei Dou
Keyword(s):  
Transfer Hydrogenation

Investigation of tetrabutylammonium bromide-glycerol-based deep eutectic solvents and their mixtures with water by spectroscopic techniques

2021 ◽  
Vol 330 ◽  
pp. 115617
Author(s):  
Renáta Chromá ◽  
Mária Vilková ◽  
Ivan Shepa ◽  
Patrycja Makoś-Chełstowska ◽  
Vasil Andruch
Keyword(s):  
Tetrabutylammonium Bromide ◽  
Deep Eutectic Solvents ◽  
Spectroscopic Techniques

scholarly journals New Bifunctional Bis(azairidacycle) with Axial Chirality via Double Cyclometalation of 2,2′-Bis(aminomethyl)-1,1′-binaphthyl

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1165
Author(s):  
Yasuhiro Sato ◽  
Yuichi Kawata ◽  
Shungo Yasui ◽  
Yoshihito Kayaki ◽  
Takao Ikariya
Keyword(s):  
Hydrogen Transfer ◽  
Bond Cleavage ◽  
Enantiomeric Excess ◽  
Transfer Hydrogenation ◽  
Catalyst Precursor ◽  
Asymmetric Catalysts ◽  
Axially Chiral ◽  
Diastereomeric Mixture ◽  
Raney Ni ◽  
Half Sandwich

As a candidate for bifunctional asymmetric catalysts containing a half-sandwich C–N chelating Ir(III) framework (azairidacycle), a dinuclear Ir complex with an axially chiral linkage is newly designed. An expedient synthesis of chiral 2,2′-bis(aminomethyl)-1,1′-binaphthyl (1) from 1,1-bi-2-naphthol (BINOL) was accomplished by a three-step process involving nickel-catalyzed cyanation and subsequent reduction with Raney-Ni and KBH4. The reaction of (S)-1 with an equimolar amount of [IrCl2Cp*]2 (Cp* = η5–C5(CH3)5) in the presence of sodium acetate in acetonitrile at 80 °C gave a diastereomeric mixture of new dinuclear dichloridodiiridium complexes (5) through the double C–H bond cleavage, as confirmed by 1H NMR spectroscopy. A loss of the central chirality on the Ir centers of 5 was demonstrated by treatment with KOC(CH3)3 to generate the corresponding 16e amidoiridium complex 6. The following hydrogen transfer from 2-propanol to 6 provided diastereomers of hydrido(amine)iridium retaining the bis(azairidacycle) architecture. The dinuclear chlorido(amine)iridium 5 can serve as a catalyst precursor for the asymmetric transfer hydrogenation of acetophenone with a substrate to a catalyst ratio of 200 in the presence of KOC(CH3)3 in 2-propanol, leading to (S)-1-phenylethanol with up to an enantiomeric excess (ee) of 67%.

scholarly journals Design of Iridium N-Heterocyclic Carbene Amino Acid Catalysts for Asymmetric Transfer Hydrogenation of Aryl Ketones

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 671
Author(s):  
Chad M. Bernier ◽  
Joseph S. Merola
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Enantiomeric Excess ◽  
Transfer Hydrogenation ◽  
Acid Catalysts ◽  
Asymmetric Transfer Hydrogenation ◽  
Reaction Conditions ◽  
Chiral Complexes ◽  
Acetophenone Derivatives ◽  
Aryl Ketones

A series of chiral complexes of the form Ir(NHC)2(aa)(H)(X) (NHC = N-heterocyclic carbene, aa = chelated amino acid, X = halide) was synthesized by oxidative addition of -amino acids to iridium(I) bis-NHC compounds and screened for asymmetric transfer hydrogenation of ketones. Following optimization of the reaction conditions, NHC, and amino acid ligands, high enantioselectivity was achieved when employing the Ir(IMe)2(l-Pro)(H)(I) catalyst (IMe = 1,3-dimethylimidazol-2-ylidene), which asymmetrically reduces a range of acetophenone derivatives in up to 95% enantiomeric excess.

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