Oxidative thiophenes

Thiolane oxides, Thiolene oxides, Thiophene oxides... 

Nitrile oxides, RNCO, are derivatives of fulminic acid (R = H). They can be named as fulmido-substituted parent molecules, but usually their names are derived from corresponding nitriles, for example, benzonitrile oxide, mesitonitrile oxide, thiophene-2-carbonitrile oxide. 

An increase in the PL QE of the fluorene-thiophene copolymers can be achieved by introduction of -oxidized thiophene units (although no efficient EL from such materials was reported). This aspect and the chemical structures of thiophene-iS,5 -dioxide-fluorene copolymers are discussed in more detail in Section 2.4. 

Leclerc [3] prepared regioregular and water soluble polythiophenes by oxidizing thiophene derivatives with iron (HI) chloride which were then used as optical and electrochemical detectors of double-stranded oligonucleotides. 

A variety of methods have been developed for oxidizing thiophenes to their corresponding thiophene 1-oxides and thiophene 1,1-dioxides, traditionally unstable nonaromatic compounds susceptible to Diels-Alder reactions. A review has appeared discussing the chemistry of thiophene 1-oxides . Evidence for thiophene 1-oxide (82) being a reactive intermediate in thiophene metabolism has been established by the in vivo isolation of the corresponding Diels-Alder adduct 83 . Bulky substituents help stabilize thiophene 1-oxides. For example,... 

Extrusion of sulfur dioxide from oxidized thiophene derivatives is an exceptional method to prepare cis-dienes as components for Diels-Alder reactions. An example of this approach utilizes the Diels-Alder reactivity of the furan ring in substituted 4//,6ff-thieno[3,4-c]furan-3,S-dioxides to react with a variety of dienophiles such as DMAD, dimethyl maleate and dimethyl fumarate which then lose SO2 to form another reactive diene (Eq. 17) <94H961>. A review of the preparation and use of 4i/,6f/-thieno[3,4-c]furan-S,5-dioxides as well as other heteroaromatic-fused 3-suIfolenes is report <94H1417>. The preparation of dihydrothienooxazole 80 requires the careful control of the reaction time and temperature as well as the reactants molar ratio <94JOC2241>. Specific control of the alkylation conditions for 81 (X = COCH3) allows for the preparation of either 1,4-disubstituted or 1,6-disubstituted 4, 6//-thieno[3,4-c]furan-S,S-dioxides. These molecules could be used as intermediates for the preparation of novel pentacyclic compounds <94JCS(P1)1371>. 

Thiophene-1-oxides Thiophene-1,1 -dioxides. 2.1 Reaction with nucleophiles. 2.2 Cycloaddition reactions. 2.3 Other reactions Thiophene S,N-ylides and S,C-ylides. 3.1 Cycloaddition reactions of S,N-ylides and S,C-ylides. 3.2 Cyclopropanation reactions of S,C-ylides. 3.3 Thermal transformations of thiophene S,N- and S,C-ylides Oxothiophenes Tautomeric with Hydroxythiophenes. 4.1 Tautomerism. 4.2 Alkylation and acylation. 4.3 Condensation reactions at the methylene group. 4.4 Halogenation. 4.5 Oxidative coupling. 4.6 Cycloaddition. 4.7 2,3-Diones 4 Sulfoxides and sulfones. 4.9 Photochemistry. 4.10 Macrocyclic polyethers... 

Hexamethylphosphoramide)oxodiperoxomolybdenum(VI), MoOs HMPA, is also capable of oxidizing thiophenes and benzo[Z)]thiophene to their 1,1-dioxides <85CPB5071>. 2,5-Diphenyl-thiophene gives a 37% yield of the 1,1-dioxide, while benzo[6]thiophene gives the dioxide in 86% yield. 

P3HT films with controlled thicknesses, typically ITom 1 to 19 run, are spin-cast firom P3HT-chlorobenzene solutions. By scanning the potential positively, the polymer film can be oxidized with more positive potentials that correspond to higher percentages of oxidized thiophene species. The extent of electrochemical oxidation is determined by integrating... 

Handbook of Thiophene-based Materials Applications in Organic Electronics and Photonics thiophene thiophene-1-oxide thiophene-1,1-dioxide... 

Tourillon and Gamier electrochemically oxidized thiophene in acetonitrile using tetrabutylammonium... 

Chromiun oxide-lanthanum oxide-aluminum oxide-potassium oxide Thiophenes from l,3>dienes... 

Busby E, Xia J, Low JZ, Wu Q, Hoy J, Campos LM, Sfeir MY (2015) Fast singlet exciton decay in push-pull molecules containing oxidized thiophenes. J Phys Chem B. doi 10.1021/ jp511704r... 

Thiophene 1-oxides (thiophene S-oxides) and thiophene 1,1-dioxides (thiophene S, 5-dioxides) are compounds of great importance in the field of heterocyclic and heteroatom chemistry from both synthetic and mechanistic points of view. 

Comparison of the traditional oxidants with HOF MeCN for various thiophene derivatives showed that the latter quickly converts them into the corresponding thiophene 1,1-dioxides in a few minutes with high yields, while traditional oxidants, e.g., w-CPBA, required hours or several days [73]. For some thiophene derivatives, HOF MeCN complex is the only way to fuUy oxidize thiophenes to... 

A cationic Rh-catalyst was employed in the presence of silver(I) carbonate to alkenylate heteroarylphosphine oxides. Thiophene derivatives underwent alkenylaton in modest to good yields (59-72%) using ethyl and terf-butyl acrylates (eq 38). 

---