112156-87-3Relevant academic research and scientific papers
PHOTOOXIDATION OF SOME MESOIONIC AND RELATED SYSTEMS
Kato, Hiroshi,Tani, Kazue,Kurumisawa, Haruki,Tamura, Yoshiko
, p. 717 - 720 (1980)
Photooxidation of several mesoionic compounds gave ring cleavage products, some of which were apparently formed via the endoperoxides of the mesoionic rings.Photooxidation of a Δ2-oxazolin-4-one and Δ2-thiazolin-4-one gave the corresponding 4,4'-bisoxa- and bisthiazolinone in dichloromethane, whereas the former gave benzamide in dimethylformamide.
Synthesis of symmetrical 2,2′,4,4′-tetrasubstituted [4,4′-bithiazole]-5,5′(4H,4′H)-diones and their reactions with some nucleophiles
Andersen, Kenneth K.,Bray, Diana D.,Kjaer, Anders,Lin, Yuhui,Shoja, Massud
, p. 1000 - 1015 (2007/10/03)
Symmetrical ,2′,4,4′-tetrasubstituted-[4,4′-bithiazole]-5,5′(4H, 4′H)-diones were obtained in high yields by oxidation of 5(4H)-thiazolones by KMnO4 in acetic acid. In some cases, the isomeric 2,4′- and 2,2′-bithiazolones were also formed. Results from two crossover reactions were consistent with a free radical mechanism. Four series of thiazolones were prepared, each based on a different substituent at the 2-position; i.e., phenyl, ethoxy, ethyl and ethylthio. The effects of substituents on the isomer distributions of the dehydrodimers indicated that electronic factors were less important than steric factors. X-Ray crystallography established the structure of the dehydrodimer (4R*,4′R*)-2,2′-diethoxy-4,4′-dibenzyl-[4,4′ -bithiazole]-5,5′(4H,4′H)-dione. One stereoisomer of 2,2′-diphenyl-4,4′-dimethyl-[4,4′-bithiazole]-5,5′(4H, 4′H)-dione and a mixture of the stereoisomers of 2,2′ -diphenyl-4,4′-dibenzyl-[4,4′-bithiazole]-5,5′(4H,4′H)- dione were treated with nucleophiles. The former gave imide derivatives of ,′-dehydrodimeric amino acids when the nucleophile was L-alanine ethyl ester or 1-butylamine. The structure of one of the reaction products, (4R*,5R*)-2,5-diphenyl-2-thiazoline-4-carboxylic acid piperidylamide, was established by X-ray crystallography. Treatment of stereoisomeric mixtures of 2,2′-diethoxy-4,4′-bithiazolones with HCl in benzene gave the corresponding racemic and meso bis-(N-carboxythioanhydride)s. A stereoisomeric mixture of the bis(N-carboxythioanhydride)s of leucine treated with glycine ethyl ester gave a bicyclic derivative of the ,′-dehydrodimeric amino acid. Acta Chemica Scandinavica 1997.
PHOTOCHEMICAL AND THERMAL REACTIONS OF HETEROCYCLES. IV. PHOTO-OXIDATION REACTIONS OF MESOIONIC DITHIOLIUMOLATE, THIAZOLIUMOLATE, AND RELATED HETEROCYCLES. SOLVENT EFFECTS ON THE COURSE OF THE PHOTO-OXIDATION
Kato, Hiroshi,Tani, Kazue,Kurumisawa, Haruki,Tamura, Yoshiko
, p. 1313 - 1322 (2007/10/02)
Photo-oxidation of mesoionic 1,3-dithiolium-4-olates (1) gave diacyl disulfide (2), and that of a mesoionic thiazolium-4-olate (6) and oxazolium-5-olate (9) gave diacylamides as the main products.The formation of these products was rationalized by a route involving fragmentation of the corresponding endoperoxides, which are formed by cycloaddition of singlet oxygen on the mesoionic rings.Photo-oxidation of 5(4H)-oxazolones (12) and a 5(4H)-thiazolone (17) in dichloromethane gave the corresponding dehydro-dimers, while that of the former in dimethylformamide gave mainly diacylamides.The acylamides were considered to arise via the endoperoxides of the mesoionic tautomers.
