Advances in the Chemistry of 2,4,6-Tri(thiophen-2-yl)-1,3,5-triazine.

Heterocyclic systems are now considered to be an integral part of material chemistry. Thiophene, selenophene, furan, pyrrole, carbazole, triazine and others are some such examples worth mentioning. 2,4,6-Tri(thiophen-2-yl)-1,3,5-triazine is a C -symmetric system with thiophene as the donor unit and s-triazine as the acceptor unit.

Synthesis of bent-shaped π-extended thienoacenes from 2,5-distannylated 3,4-dialkynethiophene.

Bent-shaped thienoacenes show promise as next-generation organic semiconductors. Here we present the synthesis of an air-stable, pure and easily scalable thiophene precursor, 2,5-distannylated-3,4-dialkyne thiophene, starting from 3,4-dialkyne thiophene in quantitative yields. This precursor has been used for the synthesis of a versatile class of -thienoacenes comprising up to 13 fused rings, helical acenes and donor-acceptor acenes.

Polycyclic Arene-Fused Selenophenes via Site Selective Selenocyclization of Arylethynyl Substituted Polycyclic Arenes.

Arene-fused selenophenes were synthesized by a redox neutral process from arylethynyl substituted polycyclic arenes using selenium powder in refluxing -methyl-2-pyrrolidone (NMP) with the assistance of the residual water in NMP as a catalytic proton source. The site-selective nature of this selenocyclization produces -alkenes as a competitive product, which is dependent on the π-electron donation ability of polycyclic arenes and the kind of arylethynyl group attached to it. DFT calculations were performed to understand the site selectivity in the selenophene formation reaction.

Boron difluoride formazanates with thiophene and 3,4-ethylenedioxythiophene capping and their electrochemical polymerization.

We report here the first example of BF2 formazanates with thiophene capping and their π-conjugated polymers in the form of electroactive uniform thin films by electrochemical polymerization. These new formazanates and their polymers possess panchromatic absorption with low lying frontier molecular orbitals. With small band gaps (1.

Abnormal Nucleophilic Substitution on Methoxytropone Derivatives: Steric Strategy to Synthesize 5-Substituted Azulenes.

Azulene is a non-alternant non-benzenoid aromatic system, and in turn, it possesses unusual photophysical properties. Azulene-based conjugated systems have received increasing interest in recent years as optoelectronic materials. Despite the routes available for the preparation of substituted azulene derivatives, there remain few methods that allow regioselective substitution on the seven-membered ring of azulenes due to the subtle reactivity difference among the various positions.

Radical-Cascade Avenue for 3,4-Fused-Ring-Substituted Thiophenes.

A single-step intramolecular radical cascade reaction of diynes and thioacetic acid in the presence of a catalytic amount of azobis(isobutyronitrile) as a radical initiator has been developed to synthesize thiophenes. This method allows easy and effective construction of a thiophene scaffold having 3,4-fused-ring substitution and unsubstituted 2,5-positions for further functionalization and polymerization. Using this method, derivatives of cyclopenta[ c]thiophene, 3,4-ethylenedioxythiophene, and thiophene-containing spirocyclic compound have been synthesized.