105-07-7Relevant academic research and scientific papers
Selectivity Modulation of the Ley–Griffith TPAP Oxidation with N-Oxide Salts
Moore, Peter W.,Jiao, Yanxiao,Mirzayans, Paul M.,Sheng, Lexter Ng Qi,Hooker, Jordan P.,Williams, Craig M.
, p. 3401 - 3407 (2016)
A wide variety of novel non-hygroscopic N-oxide tetraphenylborate salts were synthesized and evaluated as co-oxidants in the Ley–Griffith (TPAP) oxidation of benzylic and allylic alcohols under non-anhydrous conditions. The novel DABCOO·TPB (2:1) salt was herein unearthed as a viable competitor to the first-generation NMO·TPB (2:1) salt, but more importantly gave increased performance under oxidative competition. X-ray crystal structure analysis and NMR spectroscopy revealed that depending on the crystallization conditions 1:1, 2:1 or 3:2 N-oxide–tetraphenylborate salts could be formed.
Efficient cyanation of aryl bromides with K4[Fe(CN)6] catalyzed by a palladium-indolylphosphine complex
Yeung, Pui Yee,Tsang, Chun Pui,Kwong, Fuk Yee
, p. 7038 - 7041 (2011)
This study describes a general palladium-catalyzed cyanation of aryl bromides using K4[Fe(CN)6] as the cyanide surrogate. The reactions can be successfully conducted under mild reaction conditions (at 50 °C) in mixed solvents (water/MeCN = 1:1) without any surfactant additives, and afford the desired aryl nitriles in good-to-excellent yields. Particularly noteworthy is that this system allows the mildest reaction temperature reported so far for palladium-catalyzed cyanation of aryl bromides with K 4[Fe(CN)6] source in general. Common functional groups, including keto, aldehyde, free amine, and heterocyclic substrates are compatible under this system. Interestingly, the phosphine ligands bearing -PCy 2 moiety, which usually show excellent activity in aryl halide couplings, are found less effective than the corresponding ligands with -PPh2 group.
Copper-catalyzed cyanation of arylboronic acids using DDQ as cyanide source
Zhang, Guangyou,Chen, Shuyou,Fei, Haiyang,Cheng, Jiang,Chen, Fan
, p. 2247 - 2250 (2012)
In this paper, a copper-catalyzed cyanation of arylboronic acids is achieved with DDQ, providing nitriles with good yields. This new approach represents a safe method for the synthesis of aryl nitriles. Georg Thieme Verlag Stuttgart ? New York.
Mild palladium-catalyzed cyanation of (hetero)aryl halides and triflates in aqueous media
Cohen, Daniel T.,Buchwald, Stephen L.
, p. 202 - 205 (2015)
A mild, efficient, and low-temperature palladium-catalyzed cyanation of (hetero)aryl halides and triflates is reported. Previous palladium-catalyzed cyanations of (hetero)aryl halides have required higher temperatures to achieve good catalytic activity. This current reaction allows the cyanation of a general scope of (hetero)aryl halides and triflates at 2-5 mol % catalyst loadings with temperatures ranging from rt to 40 °C. This mild method was applied to the synthesis of lersivirine, a reverse transcriptase inhibitor.
An effective synthesis of N,N-dimethylamides from carboxylic acids and a new route from N,N-dimethylamides to 1,2-diaryl-1,2-diketones
Kumagai, Takashi,Anki, Tomohiro,Ebi, Takahiro,Konishi, Akihito,Matsumoto, Kouzou,Kurata, Hiroyuki,Kubo, Takashi,Katsumoto, Kenta,Kitamura, Chitoshi,Kawase, Takeshi
, p. 8968 - 8973 (2010)
Carboxylic acids were heated at 150 °C in DMF in the presence of 1.25 equiv of thionyl chloride to give corresponding N,N-dimethylamides in good yields. Tandem chlorination and amidation reactions occurred in the one-pot procedure. Dicarboxylic acids needed prolonged reaction time to produce bisamides in good yields. Some benzamides were efficiently converted into corresponding 1,2-diaryl-1,2-diketones (benzils) under acyloin condensation conditions in the presence of 4,4′-di-tert-butylbiphenyl (DBB) in THF. Ultrasonic irradiation effectively accelerates the reaction, but it is not critical. However, the presence of DBB is fatal to the reaction. Although a few synthetic methods for benzils from benzoic acids have been reported so far, this method is one of the most convenient and highly reproducible procedures.
Electrochemical Activation of Galactose Oxidase: Mechanistic Studies and Synthetic Applications
Fryszkowska, Anna,Klapars, Artis,Marshall, Nicholas,Ruccolo, Serge,Strotman, Neil A.,Zhang, Shaoguang
, p. 7270 - 7280 (2021)
The enzyme galactose oxidase (GOase) is a copper radical oxidase that catalyzes the aerobic oxidation of primary alcohols to the aldehydes and has been utilized to that end in large-scale pharmaceutical processes. To maintain its catalytic activity and ensure high substrate conversion, GOase needs to be continuously (re)activated by 1e- oxidation of the constantly formed out-of-cycle species (GOasesemi) to the catalytically active state (GOaseox). In this work, we report an electrochemical activation method for GOase that replaces the previously used expensive horseradish peroxidase activator in a GOase-catalyzed oxidation reaction. First, the formation of GOaseox of a specifically engineered variant via nonenzymatic oxidation of GOasesemi was studied by UV-vis spectroscopy. Second, electrochemical oxidation of GOase by mediators was studied using cyclic voltammetry. The electron-transfer rates between GOase and various mediators at different pH values were determined, showing a dependence on both the redox potential of the mediator and the pH. This observation suggests that the oxidation of GOase by mediators at pH 7-9 likely occurs via a concerted proton-coupled electron-transfer (PCET) mechanism under anaerobic conditions. Finally, this electrochemical GOase activation method was successfully applied to the development of a bioelectrocatalytic GOase-mediated aerobic oxidation of benzyl alcohol derivatives, cinnamyl alcohol, and aliphatic polyols, including the desymmetrizing oxidation of 2-ethynylglycerol, a key step in the biocatalytic cascade used to prepare the promising HIV therapeutic islatravir.
New selective metal-free oxidations of primary alcohols by HNO3 or HNO3 and O2, catalyzed by Br2
Minisci, Francesco,Porta, Ombretta,Recupero, Francesco,Punta, Carlo,Gambarotti, Cristian,Pierini, Monica,Galimberti, Laura
, p. 2203 - 2205 (2004)
Primary benzylic alcohols are selectively oxidized to the corresponding aromatic aldehydes by molecular oxygen at atmospheric pressure, under Br 2-HNO3 catalysis in a biphasic medium (1,2-dichloroethane- water, 5:1) at 60 °C. Under paragonable experimental conditions the aliphatic alcohols are oxidized to esters.
4CzIPN catalyzed photochemical oxidation of benzylic alcohols
Zhang, Heng,Guo, Tianyun,Wu, Mingzhong,Huo, Xing,Tang, Shouchu,Wang, Xiaolei,Liu, Jian
, (2021)
A green photoredox oxidation of benzylic primary and secondary alcohols to aldehydes and ketones with air as an oxidant was reported. The oxidation shows broad substrate scope and excellent selectivity over benzylic alcohols to the aliphatic alcohols. Further mechanistic studies revealed a quinuclidine mediated HAT process, and blue LEDs promoted 4CzlPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene) photoredox cycle were involved in our oxidation.
Tungstate-loaded triazine-based magnetic poly(Bis-imidazolium ionic liquid): An effective bi-functional catalyst for tandem selective oxidation/Knoevenagel condensation in water
Zohreh, Nasrin,Tavakolizadeh, Maryam,Hosseini, Seyed Hassan,Pourjavadi, Ali,Bennett, Craig
, p. 342 - 350 (2017)
A novel bi-functional polymeric catalyst was synthesized by immobilization of tungstate anions onto the nitrogen rich poly(ionic liquid)/magnetic nanocomposite. The resulting catalyst has two types of catalytic sites: (i) immobilized WO4 anions with bis-imidazolium ionic liquid cation for selective oxidation of alcohols and (ii) basic amine groups for Knoevenagel condensation between produced aldehyde and malononitrile. Due to the polymeric nature of the catalyst, large amounts of tungstate and basic nitrogen groups were presented on the solid surface which led to a decrease in the applied catalyst mass for catalytic reaction. High catalytic activity and excellent selectivity of catalyst in water medium make this protocol a green way for production of fine chemicals.
Efficient and Highly Selective Solvent-Free Oxidation of Primary Alcohols to Aldehydes Using Bucky Nanodiamond
Lin, Yangming,Wu, Kuang-Hsu Tim,Yu, Linhui,Heumann, Saskia,Su, Dang Sheng
, p. 3497 - 3505 (2017)
Selective oxidation of alcohols to aldehydes is widely applicable to the synthesis of various green chemicals. The poor chemoselectivity for complicated primary aldehydes over state-of-the-art metal-free or metal-based catalysts represents a major obstacle for industrial application. Bucky nanodiamond is a potential green catalyst that exhibits excellent chemoselectivity and cycling stability for the selective oxidation of primary alcohols in diverse structures (22 examples, including aromatic, substituted aromatic, unsaturated, heterocyclic, and linear chain alcohols) to their corresponding aldehydes. The results are comparable to reported transition-metal catalysts including conventional Pt/C and Ru/C catalysts for certain substrates under solvent-free conditions. The possible activation process of the oxidant and substrates by the surface oxygen groups and defect species are revealed with model catalysts, ex situ electrochemical measurements, and ex situ attenuated total reflectance. The zigzag edges of sp2 carbon planes are shown to play a key role in these reactions.
