Synthesis and properties of a benzo[1,2-b:4,5-b′]dithiophene core π-system that bears alkyl, alkylthio and alkoxy groups at 3,7-positions

Benzo-thia-fused [n]thienoacenequinodimethanes with small to moderate diradical characters: the role of pro-aromaticity versus anti-aromaticity

“…The synthetic route to BDTh-TIPS shown in Scheme 2 is slightly different from that to Th n -TIPS ( n = 1–3). Instead of dibromo-diesters 4–6 , the ditriflate-diester compound 16 12 was used to carry out a direct nucleophilic substitution reaction with 4- tert -butylbenzenethiol under basic conditions to give compound 17 in 91% yield as the triflate is a good leaving group. Subsequent reactions following a similar protocol to that shown in Scheme 1 gave the target compound BDTh-TIPS in an acceptable yield.…”

Synthesis of [1]benzothieno[3,2-b][1]benzothiophene (BTBT) and its higher homologs through palladium-catalyzed intramolecular decarboxylative arylation

“…Preparation of 2-aryl-3-(arylthio)benzo [b]thiophene by nucleophilic arylthiolation and decarboxylative arylation (previous work). 11 We first examined the synthesis of mother BTBT by using methyl 3-[(trifluoromethyl)sulfonyloxy]-benzo [b]thiophene-2carboxylate (1b) 12 as the starting material to test the applicability of the triflate analog of 1a (Scheme 2), since the leaving group is required to construct a higher BTBT analog (vide infra). Yields of 3a and 3b were 53% and 65%, respectively (by two steps).…”

“…6 We next examined the synthesis of BBTBDT by using di(2ethylhexyl) 3,7-bis(trifluoromethanesulfonyloxy)benzo[1,2b:4,5-b′]dithiophene-2,6-carboxylate (1c) as the synthetic scaffold (Scheme 3), the preparation of which starting from commercially available 2,5-dibromoterephthalic acid was recently described by us. 12 The reaction of 1c with 2a followed by hydrolysis gave the corresponding diacid 6a in 42% yield (by two steps) and the subsequent decarboxylative cyclization afforded BBTBDT in 61% yield (18% after sublimation in vacuo). The physical properties of BBTBDT have been reported.…”

The Influence of Solubilizing Chain Stereochemistry on Small Molecule Photovoltaics

“…), solubilizing groups emerge as important structural components for study and material/device optimization. Indeed, for both oligomers and polymers, side chain type, length, branching, placement, and stereochemistry have independently been shown to influence thin film morphology, charge carrier mobility, and device performance …”