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• 121-43-7 Trimethyl borate 
• 492-97-7 2,2'-Bithiophene 
• 626-39-1 1,3,5-trisbromobenzene 
• 162717-58-0 2-(tri-n-butyl)stannyl-5,2'-bithiophene 

Relevant academic research and scientific papers

Meta-substituted thienyl benzenes: A comparative Synthetic, structural and computational study

A selection of metal-catalyzed C-C bond-forming strategies has been evaluated in the synthesis of a series of meta-substituted thienylbenzenes, (Tn)2C6H4 and (Tn) 3C6H3 (n = 1, 2; T1 = 2-thienyl; T2 = 2, 2′-bithien-5-yl). Kumada coupling reactions catalyzed by PdCl2(dppf) between the appropriate thienyl Grignard and either 1, 3- or 1, 3, 5-bromo- or iodobenzenes were found to be the most reliable in terms of convenience, selectivity and yield (dppf = 1, 1′- bis(diphenylphosphino)ferrocene). These conditions also allowed the optimized syntheses of mixed (thienyl)(halo)benzenes, (Tn)C6H 3X2 and (Tn)2C6H 3X(X = Br, I); the latter bromides could be further elaborated in subsequent Stille, Sonogashira, or Kumada reactions to furnish bis(thienyl) compounds bearing electron-donating or -withdrawing groups in the third meta position, (Tn)2C6H3R (R= Ph, p-MeOC6H4, p-FC6H4; n = 1, 2) and (T1)2C6H3R′ (R′ = Me, C=CPh, Fc; Fc = ferrocenyl). The relative effects of R, R′, and n were evaluated by electronic spectroscopy, cyclic voltammetry and calculation. The absorption and emission characteristics and calculated ionization potentials and HOMO-LUMO gaps of these compounds were strongly dependent on n and largely insensitive to R/R′. These measured and calculated properties were also found to be largely invariant with respect to the degree of substitution about the central ring in the meta-substituted benzenes (Tn) mX3-mC6H3 (m = 1-3; n = 1, 2; X = Br, H), although in the case of n = 1, there was a smooth, albeit small, increase in the emission maximum with increasing thienyl substitution. These findings essentially confirmed earlier theoretical predictions that the thienyl "arms" of meta-substituted phenyl-cored dendrimers were predominantly responsible for absorption and that excitons were localized to the "arms" without any electronic coupling between them, but also introduced the caveat that there was a minimum of two contiguous thiophene rings required for strict exciton localization to the arms. The oxidation potentials of the compounds in solution ranged from 0.9 to 1.6 V and were not rationally dependent on the degree of substitution or the nature of R/R′.

PROCESS FOR PRODUCING DENDRIMER, BUILDING BLOCK COMPOUND, AND PROCESS FOR PRODUCING THIOPHENE COMPOUND

A method for producing a dendrimer having a structural repeating unit which is represented by formula (1) and which contains a linear portion including a thienylene moiety and a branch portion Y formed of an optionally substituted trivalent organic group. The method is based on the convergent method and includes reaction step 1 of converting α-position hydrogen of the thiophene ring of a thienylene-moiety-containing compound (a) for forming end moieties to an active group V1 which undergoes Suzuki cross-coupling reaction, to thereby form compound (b); reaction step 2 of subjecting a compound (c) to Suzuki cross-coupling reaction with the compound (b), to thereby yield compound (d), the compound (c) having a linear portion and a branch portion Y and having, at the branch portion Y, two active groups V2 which undergo Suzuki cross-coupling reaction with the active group V1; reaction step 3 of converting α-position hydrogen of the thiophene ring of the thus-formed compound to an active group V1 which undergoes Suzuki cross-coupling reaction, and reacting the compound (c) with the active group V1, to thereby form a dendron of a subsequent generation; and a step of repeating the reaction step 3 in accordance with needs, to thereby form a dendrimer.