35500-04-0Relevant academic research and scientific papers
NaHSO4/SiO2catalyzed generation of: o -quinone/ o -thioquinone methides: synthesis of arylxanthenes/ arylthioxanthenes via oxa-6π-electrocyclization
Anthony, Savarimuthu Philip,Karthick, Muthupandi,Konikkara Abi, Edwin,Ramanathan, Chinnasamy Ramaraj,Someshwar, Nagamalla
, p. 8653 - 8667 (2020/11/17)
ortho-Quinone methides, very reactive transient intermediates, are utilized successfully in synthesizing complex organic molecules of natural and biological significance. Among several synthetic protocols, the acid catalyzed generation of ortho-quinone me
Synthesis of new thioxanthenes by organocatalytic intramolecular Friedel–Crafts reaction
Yildiz, Tülay
, p. 2177 - 2188 (2018/07/21)
An efficient organocatalytic route has been developed to synthesize novel substituted thioxanthenes (2a–2v) starting from diaryl thioether alcohols (1a–1v) using the intramolecular Friedel–Crafts reaction. The starting materials were obtained in two stage
A classical but new kinetic equation for hydride transfer reactions
Zhu, Xiao-Qing,Deng, Fei-Huang,Yang, Jin-Dong,Li, Xiu-Tao,Chen, Qiang,Lei, Nan-Ping,Meng, Fan-Kun,Zhao, Xiao-Peng,Han, Su-Hui,Hao, Er-Jun,Mu, Yuan-Yuan
, p. 6071 - 6089 (2013/09/12)
A classical but new kinetic equation to estimate activation energies of various hydride transfer reactions was developed according to transition state theory using the Morse-type free energy curves of hydride donors to release a hydride anion and hydride acceptors to capture a hydride anion and by which the activation energies of 187 typical hydride self-exchange reactions and more than thirty thousand hydride cross transfer reactions in acetonitrile were safely estimated in this work. Since the development of the kinetic equation is only on the basis of the related chemical bond changes of the hydride transfer reactants, the kinetic equation should be also suitable for proton transfer reactions, hydrogen atom transfer reactions and all the other chemical reactions involved with breaking and formation of chemical bonds. One of the most important contributions of this work is to have achieved the perfect unity of the kinetic equation and thermodynamic equation for hydride transfer reactions. The Royal Society of Chemistry.
A new synthetic route to unsymmetrical 9-arylxanthenes
Das, Sajal Kumar,Singh, Ritesh,Panda, Gautam
scheme or table, p. 4757 - 4761 (2010/02/28)
A. facile and general three-step synthetic route towards unsymmetrical 9-arylxanthenes was developed. The reaction sequence involves nucleophilic substitution of commercially available 2-fluorobenzaldehydes with arenoxides, Grignard reaction of the resulting 2-arenoxybenzaldehydes with arylmagnesium bromides, followed by FeCl3-catalyzed intramolecular diarylmethylation of the resulting carbinols, This strategy was extended to access symmetrical as well as unsymmetrical 9-arylthioxanthenes.
Reactions of 9-phenylthioxanthene 10-oxide with organometallic reagents
Shimizu,Kataoka,Hori
, p. 842 - 845 (2007/10/02)
Reactions of 9-phenylthioxanthene 10-oxide (1) with a variety of Grignard reagents afforded 9-substituted 9-phenylthioxanthenes (2). Similarly, organolithiums reacted with the sulfoxide 1 to give the corresponding thioxanthenes 2. The structures of 9-aryl
Syntheses and Reactions of 9-Substituted 10-Phenylthioxanthenium Salts: Negative Evidence for Thia-anthracene Oligomerisation
Hori, Mikio,Kataoka, Tadashi,Shimizu, Hiroshi,Ikemori, Megumi,Aoyama, Yasuko
, p. 1209 - 1218 (2007/10/02)
Various 9-aryl-10-phenylthioxanthenium salts have been prepared and their stereochemistry determined by (1)H n.m.r. spectroscopy.Reactions of the 10-phenylthioxanthenium salts or 10-phenyl-10-thia-anthracenes with aryl-lithiums have been studied in order to investigate whether or not 10-thia-antracenes cause oligomerisation.The 10-phenylthioxanthenium salts reacted with aryl-lithiums to give 9-phenylthioxanthenes in good yields.However, 10-phenylthioxanthenium salt (19) when treated with phenyl-lithium at -15 to -20 deg C gave 9-phenylthioxanthenol (38) (17percent) together with 9-phenylthioxanthene (13) because of the lability of 10-phenyl-10-thia-anthracene to air. 10-Phenyl-9-(p-tolyl)-10-thia-anthracene (50) generated in situ from the sulphonium salt (22) and lithium diisopropylamide failed to react with p-tolyl-lithium.An isolable ylide, 9-benzoyl-10-phenyl-10-thia-anthracene (52) was treated with p-tolyl-lithium at 0 deg C to give 9-benzoylthioxanthene (4) (82percent).In contrast, 9,9,10-triphenylthioxanthenium salt (24) on treatment with phenyl-lithium gave a ring-opened product (40), a ring-contracted product (41), diphenylsulphide (42), and 9,9-diphenylthioxanthene (12).These results indicate that the 10-phenyl-thia-anthracenes or the ?-sulphuranes of thioxanthenes do not cause oligomerisation.
10-Thia-anthracenes. Part 3. A Re-examination of the Reaction of 9-Phenylthioxanthylium Salt and Phenyl-lithium
Hori, Mikio,Kataoka, Tadashi,Shimizu, Hiroshi,Ban, Masatoshi,Matsushita, Hitoshi
, p. 187 - 194 (2007/10/02)
Reaction of 9-phenylthioxanthylium salt (1) with phenyl-lithium afforded eight compounds, 9-phenyl- (2), 9,9-diphenyl- (3). 3,9-diphenyl (4), 3,9,9-triphenyl- (5), and 4,9,9-triphenyl-thioxanthene (6), 9,9'-diphenyl-9,9'-bithioxanthenyl (7), thioxanthone (8), and 9,9'-diphenyldithioxanth-9-yl peroxide (9).Their structures were determined by comparison with the authentic samples.Six samples, (3)-(6), 2,9,9-triphenyl- (30), 9-(biphenyl-4-yl)-9-phenylthioxanthene (31) were independently synthesized in order to determine the structures of two pairs of positional isomers, 3,4, and 5,6.A radical mechanism contributed to the reaction of compound (1) with phenyl-lithium.
Stereochemistry of 9-Arylthioxanthene 10-Oxides and 10,10-Dioxides
Ohno, Sachio,Shimizu, Hiroshi,Kataoka, Tadashi,Hori, Mikio
, p. 3471 - 3482 (2007/10/02)
The stereochemistry of 9-arylthioxanthene 10-oxides and 10,10-dioxides was determined by detailed investigation of the 1H-NMR spectra.These sulfoxides and sulfones were synthesized by oxidation of the corresponding 9-arylthioxanthenes with m-ch
Synthesis and Stereochemistry of 10-Alkyl-9-arylthioxanthenium Salts
Ohno, Sachio,Shimizu, Hiroshi,Kataoka, Tadashi,Hori, Mikio,Kido, Masaru
, p. 3151 - 3157 (2007/10/02)
10-Alkyl-9-arylthioxanthenium salts were synthesized by the reaction of the corresponding 9-arylthioxanthenes with alkyl iodides in the presence of silver salts.Stereochemistry of the sulfonium salts was determined by detailed investigation of the 1H NMR
Reactivity of Triplet Diphenylcarbene towards the Sulphur Atom of 1,2,3-Benzothiazole
Benati, Luisa,Montevecchi, Pier Carlo,Spagnolo, Piero,Tundo, Antonio
, p. 1544 - 1548 (2007/10/02)
Thermal decomposition of diphenyldiazomethane (1) at 87 deg C in chlorobenzene in the presence of 1,2,3-benzothiadiazole (2) afforded 9-phenylthioxanthen (3), 6-phenyl-6H-dibenzothiopyran (4), 6-benzhydryl-6-phenyl-6H-dibenzothiopyran (5) and thianthren (6).Reaction products are explained in terms of attack on the sulphur atom of (2) by triplet diphenylcarbene, leading to decomposition of the heterocyclic nucleus with loss of nitrogen and formation of a diradical intermediate (7), from which products (3)-(6) can arise.Some evidence is presented that benzothiadiazole (2) may act as an an effective spin-trap for triplet diphenylcarbene, thus preventing reversible interconversion of singlet and triplet states.
