- A donor-acceptor complex enables the synthesis of: E -olefins from alcohols, amines and carboxylic acids
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Olefins are prevalent substrates and functionalities. The synthesis of olefins from readily available starting materials such as alcohols, amines and carboxylic acids is of great significance to address the sustainability concerns in organic synthesis. Metallaphotoredox-catalyzed defunctionalizations were reported to achieve such transformations under mild conditions. However, all these valuable strategies require a transition metal catalyst, a ligand or an expensive photocatalyst, with the challenges of controlling the region- and stereoselectivities remaining. Herein, we present a fundamentally distinct strategy enabled by electron donor-acceptor (EDA) complexes, for the selective synthesis of olefins from these simple and easily available starting materials. The conversions took place via photoactivation of the EDA complexes of the activated substrates with alkali salts, followed by hydrogen atom elimination from in situ generated alkyl radicals. This method is operationally simple and straightforward and free of photocatalysts and transition-metals, and shows high regio- and stereoselectivities.
- Chen, Kun-Quan,Shen, Jie,Wang, Zhi-Xiang,Chen, Xiang-Yu
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p. 6684 - 6690
(2021/05/31)
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- Radiosynthesis and Preclinical Investigation of 11C-Labelled 3-(4,5-Diphenyl-1,3-oxazol-2-yl)propanal Oxime ([11C]SZV 1287)
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The radiosynthesis, as well as the in vivo and ex vivo biodistribution of the 11C radiolabelled 3-(4,5-diphenyl-1,3-oxazol-2-yl)propanal oxime (6, [11C]SZV 1287) are reported. SZV 1287 is a novel semicarbazide-sensitive amine oxidase
- Forgács, Viktória,Németh, Enik?,Gyuricza, Barbara,Kis, Adrienn,Szabó, Judit P.,Mikecz, Pál,Mátyus, Péter,Helyes, Zsuzsanna,Horváth, ádám István,Kálai, Tamás,Trencsényi, Gy?rgy,Fekete, Anikó,Szikra, Dezs?
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supporting information
p. 2470 - 2476
(2020/10/28)
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- A solid-supported acidic oxazolium perchlorate as an easy-handling catalyst for the synthesis of modified pyrimidine nucleosides via Vorbrüggen-type N-glycosylation
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A solid-supported acidic oxazolium perchlorate was investigated as a heterogeneous catalyst in N-glycosylation reactions using silylated modified pyrimidines and an acylated ribose or glucose to afford the corresponding pyrimidine nucleosides. This salt is a nonhygroscopic and stable powder whose activity is comparable to that of 2-methyl-5-phenylbenzoxazolium perchlorate. A reaction with this polymer catalyst can be conducted on a gram scale. Reusability of the solid-supported catalyst was also investigated.
- Basu, Nabamita,Oyama, Kin-ichi,Tsukamoto, Masaki
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supporting information
p. 1921 - 1924
(2017/04/27)
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- CuI-catalyzed and air promoted oxidative cyclization for one-pot synthesis of polyarylated oxazoles
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A facile CuI-catalyzed and air promoted oxidative cyclization was developed for the synthesis of polyarylated oxazoles. By virtue of this method, a variety of arylated oxazoles could be easily synthesized from readily available starting materials at room temperature in air. The Royal Society of Chemistry 2013.
- Hu, Ping,Wang, Qiang,Yan, Yizhe,Zhang, Shuai,Zhang, Baiqun,Wang, Zhiyong
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p. 4304 - 4307
(2013/08/23)
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- Preparation of substituted oxazoles by ritter reactions of α-oxo tosylates
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The Lewis acid catalyzed Ritter reaction of α-oxo tosylates with nitriles forms the basis of an efficient synthesis of oxazoles. Oxazoles with various substituents can be readily prepared from inexpensive starting materials. Georg Thieme Verlag Stuttgart.
- Lai, Ping-Shan,Taylor, Mark S.
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experimental part
p. 1449 - 1452
(2010/09/14)
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- 4,5-diaryl oxazole derivatives
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This invention relates to new heterocyclic compounds, compositions, process of making and method of use thereof for inhibition of platelet aggregation, vasodilation, antihypertensive activity and prostaglandin I2 agonist.
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- Convenient syntheses of 2-alkyl(Aryl)-4,5-diphenyloxazoles and 2-alkyl(Aryl)-4-phepyloxazoles
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The synthetic methods to prepare 2-alkyl(aryl)-4,5-diphenyloxazoles and 2-alkyl(aryl)-4-phenyloxazoles were improved on the basis of a mechanistic study of oxazole formation from α-hydroxy ketones (carboxylic esters of benzoin and phenacyl alcohols). By these methods, seven trisubstituted oxazoles and twelve disubstituted oxazoles of the title compounds were prepared.
- Pei, Weiwei,Li, Shaohui,Nie, Xiaoping,Li, Yiwei,Pei, Jian,Chen, Bingzi,Wu, Jie,Ye, Xiulin
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p. 1298 - 1304
(2007/10/03)
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- Studies Dealing with the Aza-Claisen Rearrangement of 2-Allyloxy-Substituted Oxazoles
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The scope of the thermal -sigmatropic rearrangement of a number of 2-allyloxy-substituted 4,5-diphenyloxazoles has been examined.These systems undergo a facile aza-Claisen rearrangement to give 3-allyl-substituted 4,5-diphenyl-4-oxazolin-2-ones.In contrast to the thermal results, irradiation of the 2-allyloxy- or benzyloxy-substituted oxazole gave rise to a mixture of 3- and 5-substituted oxazolinones.The photolysis proceeds via C-O bond scission to generate a radical pair which subsequently recombines to produce the mixture of oxazolinones.A series of related oxazoles was prepared in which the heterocyclic ring and the ? bond are connected by an alkoxy side chain.All attempts to induce an intramolecular Diels-Alder reaction failed.The only product that could be obtained corresponds to that derived from an intramolecular ene reaction.The excited-state behavior of several 2- and 5-allyloxy-substituted oxazoles was also studied.The rationale for the difference in thermal and photochemical behavior is discussed.
- Padwa, Albert,Cohen, Leslie A.
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p. 399 - 406
(2007/10/02)
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