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•A novel terthiophene monomer with a side chain TEMPO (TT-TEMPO) was synthesized successfully.•The polymer PTT-TEMPO film displayed a uniform network structure.•The PTT-TEMPO film ...electrode functioned well for selective oxidation of benzyl alcohol to benzaldehyde.
A novel monomer of terthiophene with a side chain TEMPO, 4-(2,5-di(thiophen-2-yl)thiophen-3-yl)acetyl-oxy-2,2,6,6-tetramethylpiperidin-1-yloxy (TT-TEMPO) was successfully synthesized. Its corresponding polymer PTT-TEMPO was prepared via electrochemical polymerization on Pt electrode in boron trifluoride diethyl etherate solution. PTT-TEMPO film showed a uniform network structure. Compared with bare Pt electrode, PTT-TEMPO electrode exhibited high electrocatalytic performance for oxidation of benzyl alcohol in the presence of 2,6-lutidine under similar conditions. Benzyl alcohol was selectively oxidized to benzaldehyde based on in situ FTIR analysis.
A facile and elegant method for synthesis of novel N–aryl phenothiazine derivatives from 2-phenylindolizines and phenothiazines through direct electrochemical oxidation has been developed. This ...approach was performed smoothly at room temperature without external oxidant and catalyst. Cyclic voltammetry and in situ FTIR techniques were applied to analyze the cross-coupling process of phenothiazines and 2-phenylindolizines, which helped to select the appropriate reaction potential. Under the optimized conditions, a broad range of substrates were well tolerated, affording the desired products in moderate to excellent isolated yields (up to 91%) with high regioselectivity. Meanwhile, a plausible mechanism involving a radical pathway has been proposed.
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A facile and efficient direct electrochemical oxidation method for C–H/N–H cross-coupling of 2-phenylindolizines with phenothiazines to synthesize novel N-aryl phenothiazine derivatives has been developed. Under the optimized conditions, a broad range of substrates were well tolerated, affording the desired products in moderate to excellent isolated yields (up to 91%) with high regioselectivity.
One-pot electrochemical oxidation of alcohols to nitriles was carried out with ammonium acetate as the nitrogen source and 2,2,6,6-tetramethylpiperidinyl-l-oxy (TEMPO) as the catalyst. Cyclic ...voltammetry investigation showed that an obvious redox reaction between alcohol and TEMPO occurred efficiently in the presence of NH4OAc. The constant potential electrolysis of various functionalized alcohols, especially of benzylic alcohols, afforded the corresponding nitriles in moderate to excellent yields at ambient temperature. A plausible reaction mechanism of one-pot electrochemical oxidation of alcohols to nitriles was proposed based on the cyclic voltammetry investigation, in situ FTIR analysis and preparative electrolysis.
A new transition‐metal‐free 9‐azabicyclo3.3.1nonan‐N‐oxyl (ABNO) catalyzed aerobic oxidative synthesis of 2‐substituted 4H‐3,1‐benzoxazines and quinazolines has been developed through cascade ...reaction of aldehydes with 2‐aminobenzyl alcohols and 2‐aminobenzylamines, respectively. Under the optimal reaction conditions, the two kinds of heterocycles were obtained in 72–97 % isolated yield.
A new transition‐metal‐free 9‐azabicyclo3.3.1nonan‐N‐oxyl (ABNO) catalyzed aerobic oxidative synthesis of 2‐substituted 4H‐3,1‐benzoxazines and quinazolines has been developed. Under the optimal reaction conditions, the two kinds of heterocycles were obtained in 72–97 % isolated yield.
A mild and efficient system has been discovered for the synthesis of α-aryl carbonyl compounds via oxidation of benzylic C–H to CO bonds. This ultraviolet-light-mediated oxygenation reaction ...exhibited excellent substrate scope including various xanthenes, thioxanthenes and 9, 10-dihydroacridines and afforded the corresponding ketones with good to excellent yields under catalyst- and additive-free conditions at room temperature.
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•An efficient strategy for synthesis of α-aryl carbonyl compounds has been reported.•The ultraviolet-light-mediated reaction with excellent substrate scope.•Catalyst- and additive-free at room temperature conditions.•Good to excellent yields can be obtained.
A novel TEMPO-modified polyaniline electrode, poly(4-(2-aminobenzoyl-oxy)-2,2,6,6-tetramethylpiperidin-1-yloxy) (PAn-TEMPO), was successfully prepared on glassy carbon by electrochemical ...polymerization in water/acetone. The electrocatalytic property of PAn-TEMPO for oxidation of alcohols was investigated by cyclic voltammetry, in situ FTIR and preparative electrolysis experiments. The PAn-TEMPO performed well, leading to the selective oxidation of alcohols under mild conditions. Various alcohols were efficiently oxidized to their corresponding aldehydes or ketones with excellent conversions and selectivities in water solution or water/acetonitrile solution buffered with sodium carbonate/bicarbonate.
A simple and efficient method for the direct synthesis of nitriles from aldehydes using ammonium acetate as the nitrogen source has been developed. The reactions were performed with iodine as the ...catalyst and tert-butyl hydroperoxide (TBHP) as the oxidant under mild conditions. A variety of aromatic, heteroaromatic, aliphatic and allylic aldehydes could be converted into their corresponding nitriles in good to excellent yields.
An efficient 2,3-dichloro-5,6-dicyano-1,4-benzoquinone/tert-butyl nitrite-catalyzed aerobic oxidation of diarylmethane sp3 C–H bonds in the presence of acetic acid has been developed. Under the ...optimal reaction conditions, a number of diarylmethanes can be directly converted to their corresponding diarylketones in good to excellent yields. In addition, a plausible reaction mechanism has been investigated.
Display omitted An efficient 2,3-dichloro-5,6-dicyano-1,4-benzoquinone/tert-butyl nitrite-catalyzed aerobic oxidation of diarylmethane sp3 C–H bonds in the presence of acetic acid has been developed. Under the optimal reaction conditions, a number of diarylmethanes can be directly converted to their corresponding diarylketones in good to excellent yields. In addition, a plausible reaction mechanism has been investigated.
► Pt nanoparticles are modified with polypyrrole in 1-ethylimidazolium trifluoroacetate. ► The electrocatalytic activity towards formaldehyde oxidation is improved. ► The poisoning effect of CO on ...the electrode is reduced. ► Cyclic voltammetry and
in situ FTIR spectroscopy are used.
A facile approach to improve the electrocatalytic properties of Pt nanoparticles (nm-Pts) has been developed. nm-Pts are deposited on substrate electrode Pt sheet using cyclic voltammetry in sulfuric acid containing H
2PtCl
6 to get nm-Pt electrode, and then are modified with polypyrrole in an ionic liquid 1-ethylimidazolium trifluoroacetate (PPy-HEImTfa) to obtain the electrode PPy-HEImTfa/nm-Pt. The electrocatalytic performance of PPy-HEImTfa/nm-Pt towards the oxidation of formaldehyde in acidic solution has been studied by cyclic voltammetry and
in situ FTIR spectroscopy. Results show that PPy-HEImTfa/nm-Pt exhibits high electrocatalytic activity and stability, as compared with nm-Pt electrode or PPy-HEImTfa modified with nm-Pts (nm-Pt/PPy-HEImTfa) under the similar preparation conditions.
In situ FTIR spectroscopic measurements confirm that PPy-HEImTfa film on the surface of nm-Pts help to catalyze the oxidation of the adsorbed CO and reduced the poisoning effect of CO on nm-Pt catalyst.
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