Hyperconjugated side chained benzodithiophene and 4,7-di-2-thienyl-2,1,3-benzothiadiazole based polymer for solar cells

A novel donor-acceptor (D-A) copolymer (P3TBDTDTBT), including hyperconjugated side chained benzodithiophene as a donor and 4,7-di-2-thienyl-2,1,3-benzothiadiazole (DTBT) as an acceptor, was designed and synthesized. Due to the introduction of the hyperconjugated side chain, the resultant polymer exhibited good thermal stability with a high decomposition temperature of 437 degrees C, a low band-gap of 1.67 eV with an absorption onset of 742 nm in the solid film, and a deep highest occupied molecular orbital (HOMO) energy level of -5.26 eV. Finally, the polymer solar cell (PSC) device based on this polymer and [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) showed the best power conversion efficiency (PCE) of 3.57% with an open-circuit voltage (V-oc) of 0.78 V, a short-circuit current density (J(sc)) of 8.83 mA cm(-2) and a fill factor (FF) of 53%

Palladium-Catalyzed Carbonylative Cycloisomerization of gamma-Propynyl-1,3-diketones: A Concise Route to Polysubstituted Furans

Di- and trisubstituted furan derivatives have been efficiently synthesized via palladium(II)-catalyzed intramolecular carbonylative cycloisomerization of gamma-propynyl-1,3-diketones with aryl iodides and carbon monoxide. The mechanism suggests that in situ generated acylpalladium species from the carbonylation of aryl iodide initiates the reaction followed by cyclization of the enolized isomer of a 1,3-diketone substrate via carbon-carbon triple bond activation

Metal and phosgene-free synthesis of 1H-quinazoline-2,4-diones by selenium-catalyzed carbonylation of o-nitrobenzamides

1H-Quinazoline-2,4-diones were efficiently synthesized by selenium-catalyzed carbonylation of o-nitrobenzamides under relatively mild conditions. In situ-generated carbonyl selenide (SeCO) is proposed to initiate the catalytic carbonylation. Thus, a concise transition metal and phosgene-free synthetic route to potentially bioactive-substituted 1H-quinazoline-2,4-dione derivatives has been developed. (C) 2010 Elsevier Ltd. All rights reserved

Pyridyl-supported pyrazolyl-N-heterocyclic carbene ligands and the catalytic activity of their palladium complexes in Suzuki-Miyaura reactions

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Multiple reactivities of dithranol towards 1-alkynyl Fischer carbene complexes (CO)(5)M=C(OEt)C CPh (M = Cr, W) - Efficient chemical synthesis of aromatic polyketides

Reactions of anti-psoriasis drug dithranol with 1-alkynyl Fischer carbene complexes (CO)(5)M =C(OEt)C CPh (M = Cr, W) were investigated under controlled conditions in which triethylamine-promoted C-addition, O-addition, electrophilic aromatic substitution, and cyclization consecutively occurred at up to five positions of dithranol. A remarkable solvent effect led to selective formation of polyphenolic organic and organometallic mono- and triscarbene complexes which were efficiently demetalated to the potentially bioactive aromatic polyketides with pyridine-N-oxide. All the organic and organometallic products were characterized by methods including X-ray single crystal structural determinations. These results have revealed the novel multiple reactivities of dithranol which might be associated to its clinical side effect, providing a new synthetic methodology to functionalize dithranol for medical purposes, and chemically synthesize aromatic polyketides. (C) 2009 Elsevier B. V. All rights reserved