Tetrakis thiophene synthesis

Dewar pyrroles, 2,3,4.5-tetrakis-trifluoromethyl-, synthesis from Dewar thiophenes, 60, 35... 

S. Yoneda, K. Ozaki, A. Tsubouchi, H. Kojima and K. Yanagi, Tetrakis(alkylthio)thieno[3,4-c]thiophene-synthesis, stability and reactivity, J. Heterocycl. Chem., 25, 559-563 (1988). 

Lastly, a termolecular cydization of unknown mechanism provides a useful synthesis of tetrakis(trifluoromethyl)thiophene 60 (equation 60)... 

SYNTHESIS OF (45)-[(i -l,5-CYCLOOCTADIENE)- 4-ferf-BUTYL-2-(3-DIPHENYLPHOSPHINO-THIOPHENE-2-YL)-4, 5-DIHYDROOXAZOLE IRIDIUM(I)]-TETRAKIS[3, 5-BIS(TRIFLUOROMETHYL)PHENYL]BORATE... 

Dewar tetrakis(trifluoromethyl)thiophene, (59), has served as a dieneophile (dipolarophile) in several cycloadditions. Diels-Alder reaction of (59) with butadiene <8icci289> and pyrrole (82JA847) has served as the starting point for the synthesis of 1,2,3,8-tetrakis(trifluoromethyl)cyclooctatetraene (60) and tetrakis(trifluoromethyl)Dewar furan (61), respectively, as illustrated in Scheme 20. It is noteworthy that (61) was unattainable by direct photolysis of the substituted furan. Moreover, (59) served as a common precursor for the preparation of tetrakis- (80JA6633) and penta-<83JA3563> (trifluoromethyl)cyclopentadienides (64) and (65), respectively (Scheme 21). Accordingly, photolysis... 

So far, the formation of valence-bond isomers by photolysis has mainly been discussed. Tetrakis(trifluoromethyl) Dewar thiophene is stable at room temperature and was used for the synthesis of Dewar pyrroles, a Dewar furan, and other interesting compounds from the standpoint of the structural chemistry. In this section, some of these reactions will be discussed. 

The environmentally benign synthesis of arylated thiophenes 147 in pure water is possible via desulfinylative cross-coupling between nucleophilic 2-thienylsulfinates 146 and differently substituted bromoarenes (Scheme 58, Table 36) [356]. The reaction proceeds efficiently within short reaction times in the presence of tetrakis (triphenylphosphine)palladium(O) (Pd(PPh3)4) without the need for additives, base, cocatalysts, or water-soluble ligands. Additionally, the apphcation of a highly aqueous solvent mixture consisting of water and iV,A -dimethylformamide at a ratio of 3 1... 

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