Palladium-Catalyzed C−H Homocoupling of Bromothiophene Derivatives and Synthetic Application to Well-Defined Oligothiophenes

Abstract

Synthesis of oligothiophenes of well-defined structures that possess 2-8 thiophene units is performed with a new synthetic strategy involving C-H homocoupling of bromothiophenes and cross-coupling with organostannanes. Tolerance of the carbon-bromine bond to the palladium-catalyzed C-H homocoupling results in oligothiophenes bearing C-Br bonds at the terminal thiophene rings, which allow further transformation by the catalysis of a transition-metal complex.

Four-coordinate Pd(II) complexes containing non-symmetric phosphorus ylides: Synthesis, characterization, and catalytic behavior towards Suzuki reaction

“…As expected, very satisfactory results were obtained with the 2-bromothiophene and 1-bromonaphthalene of the arylboronic acid (entries 7e8, 13e14) with good yields. Several homocoupling reactions of thiophene derivatives have been shown to proceed with a transition-metal catalyst [51]. Especially, the homocoupling reactions have been monitored, when bromothiophene was employed.…”

Synthesis of functionalized thiophene/phenyl co-oligomers by direct arylation of thiophenes

“…In a next step we tested a protocol reported by A. Mori et al [42][43][44] who were able to couple 2-bromothiophenes with aryl iodides: the 4'-functionalized 4-iodobiphenyls were reacted with 2-functionalized thiophenes using 5 mol-% [PdCl 2 (PPh 3 ) 2 ], PPh 3 , potassium fluoride, and silver nitrate as the catalytic system to obtain the thiophenylphenylenes in moderate to acceptable yields of 58% (9) and 33% (10) (Scheme 3). Whereas the solubility of 9 is sufficient for purification via column chromatography, 10 was purified by filtering the precipitated product and repeatedly washing with various solvents.…”

New semiconducting copolymers containing alkyl quarterthiophene and alkoxy naphthalene moieties for organic thin film transistors

“…5,5'-Dibromo-5,5'-dithiophene-4,4'-didodecyl-2,2'-bithiophene was prepared with oxidation coupling and stille coupling reaction of 5,5'-dibromo-4,4'-didodecyl-2,2'-bithiophene and 2-(tri-n-butylstannyl)thiophene and then bromination. 24 Diboronic ester monomers were prepared by the boration of 2,6-dibromo-1,5-bis(hexyloxy) naphthalene and 2,6-dibromo-1,5-bis(octyloxy)naphthalene after lithiation.…”

“…5,5'-Dibromo-4,4'-didodecyl-2,2'-bithiophene (1).The compound was synthesized according to the previously published literature with yield of 65% 24. 1 H NMR (300 MHz, CDCl 3 ) (ppm): 6.79 (s, 2H), 2.52 (t, 4H), 1.28 (m, 40H), 0.90 (t, 6H).…”