- Overcoming Electron-Withdrawing and Product-Inhibition Effects by Organocatalytic Aerobic Oxidation of Alkylpyridines and Related Alkylheteroarenes to Ketones
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An organocatalyzed aerobic benzylic C-H oxidation of alkyl and aryl heterocycles has been developed. This transition metal-free method is able to overcome the electron-withdrawing effect as well as product-inhibition effects in heterobenzylic radical oxidation. A variety of ketones bearing N-heterocyclic groups could be prepared under relatively mild conditions with moderate to high yields.
- Wang, Hua,Liu, Jie,Qu, Jian-Ping,Kang, Yan-Biao
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p. 3942 - 3948
(2020/03/23)
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- Base metal-catalyzed benzylic oxidation of (aryl)(heteroaryl)methanes with molecular oxygen
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The methylene group of various substituted 2- and 4-benzylpyridines, benzyldiazines and benzyl(iso)quinolines was successfully oxidized to the corresponding benzylic ketones using a copper or iron catalyst and molecular oxygen as the stoichiometric oxidant. Application of the protocol in API synthesis is exemplified by the alternative synthesis of a precursor to the antimalarial drug Mefloquine. The oxidation method can also be used to prepare metabolites of APIs which is illustrated for the natural product papaverine. ICP-MS analysis of the purified reaction products revealed that the base metal impurity was well below the regulatory limit.
- Sterckx, Hans,De Houwer, Johan,Mensch, Carl,Herrebout, Wouter,Tehrani, Kourosch Abbaspour,Maes, Bert U.W.
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supporting information
p. 144 - 153
(2016/04/05)
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- Synthesis of aryl(di)azinyl ketones through copper- and iron-catalyzed oxidation of the methylene group of aryl(di)azinylmethanes
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Sustainable Oxidations: An oxidation method to transform aryl(di)azinylmethanes into aryl(di)azinyl ketones is described. Base metals (copper and iron) as catalysts in combination with O2 as the oxidant are used, which makes this method sustainable. The utility of this method is illustrated by the synthesis of 6-(4-methylbenzoyl)pyridine-2-carbaldehyde, which is an intermediate in the preparation of the drug Acrivastine. Copyright
- De Houwer, Johan,Abbaspour Tehrani, Kourosch,Maes, Bert U. W.
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supporting information; experimental part
p. 2745 - 2748
(2012/04/10)
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- Analogues of fenarimol are potent inhibitors of trypanosoma cruzi and are efficacious in a murine model of chagas disease
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We report the discovery of nontoxic fungicide fenarimol (1) as an inhibitor of Trypanosoma cruzi (T. cruzi), the causative agent of Chagas disease, and the results of structure-activity investigations leading to potent analogues with low nM IC50s in a T. cruzi whole cell in vitro assay. Lead compounds suppressed blood parasitemia to virtually undetectable levels after once daily oral dosing in mouse models of T. cruzi infection. Compounds are chemically tractable, allowing rapid optimization of target biological activity and drug characteristics. Chemical and biological studies undertaken in the development of the fenarimol series toward the goal of delivering a new drug candidate for Chagas disease are reported.
- Keenan, Martine,Abbott, Michael J.,Alexander, Paul W.,Armstrong, Tanya,Best, Wayne M.,Berven, Bradley,Botero, Adriana,Chaplin, Jason H.,Charman, Susan A.,Chatelain, Eric,Von Geldern, Thomas W.,Kerfoot, Maria,Khong, Andrea,Nguyen, Tien,McManus, Joshua D.,Morizzi, Julia,Ryan, Eileen,Scandale, Ivan,Thompson, R. Andrew,Wang, Sen Z.,White, Karen L.
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supporting information; experimental part
p. 4189 - 4204
(2012/07/27)
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- Synthesis of New ν-Triazolopyrimidinium Salts
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New ν-triazolo- and ν-triazolopyrimidinium salts 12a-e, 13a-c have been synthesized via oxidation (i.e. cyclohydrogenation) of the appropriate pyrimidyl ketone arylhydrazones 3a-e, 6a-c using TBB (2,4,4,6-tetrabromocyclohexa-2,5-dien-1-one)
- Batori, S.,Messmer, A.
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p. 1041 - 1046
(2007/10/02)
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