[en] Palladium-catalyzed heteroannulation of 2-amino-3-iodoquinoline derivatives and 1-trimethylsilyl internal alkynes provided highly regioselective pyrrolo(2,3-b)quinolines with trimethylsilyl group next to the nitrogen atom in the pyrrole ring

[en] We have developed a one-step synthesis of benzofurans from o-iodophenol and various terminal alkynes, by using Pd catalyst supported on nano-sized carbon balls (NCB) under copper- and ligand free conditions. This recyclable catalyst could be reused more than 5 times in the same heteroannulation reaction. The results have demonstrated that diverse 2-substituted benzofurans with tolerant functional groups can be prepared simply and conveniently under these conditions

[en] Simple and efficient N-arylation of carbazoles has been achieved by catalytic CuI reaction without any organic ligand. Although the required long reaction time for the N-arylation of carbazole, the N-arylation of halocarbazoles is promising results for diversification of the carbazole moiety. The facile variation of arylhalide and carbazole moieties is very important merits for diversification to biological and OLED materials science. We will further examine the synthesized N-arylated bromocarbazole intermediates for possible applications in material science. Natural carbazole moieties show various interesting biological activities, such as antibacterial, antiinflammatory, protein kinase inhibitory, and antitumor effects. Recently, synthetic carbazoles and derivatives have been widely used as functional building blocks for optoelectronic applications, due to their specific optical and electrochemical properties. Organometallic complexes of carbazole have been reported as potential luminescent materials for use in organic light-emitting devices (OLEDs). The carbazole moiety can be readily functionalized or covalently linked to other molecules, and numerous ways are known for enhancing its conjugated electron system. Specifically, the 2,7- and 3,6- linking of carbazole molecules with heterocycles or diaryl-amine can produce useful organic materials for photovoltaic devices, white light-emitting diodes, and LEDs. Additionally, polymeric carbazole derivatives have attracted interest for use in solid-state dye-sensitized solar cells

[en] As a part of our continuing organometallic studies on diversification of nitrogen-containing biologically active heterocycles, we attempted to synthesize furo[2,3-b]- and furo[3,2-c]quinolines starting from o-halohydroxyquinolines and terminal alkynes with heterogeneous Pd(OAc)2 catalyst, which was supported by nanosized pore carbon ball. 2-substituted furo[2,3-b]quinolines and furo[3,2-c]quinolines were synthesized from the reaction of 3-iodoquinolin-2-ol and 3-iodoquinolin-4-ol, respectively, with diverse alkynes. The heteroannulation reaction proceeds with Sonogashira coupling followed by 5-endo-dig cyclization in good isolated yields under copper and ligand free conditions

[en] A simple, efficient Cu_2O catalyst system under microwave irradiation was developed for N-arylation of various indoles without ligands and additives. Diverse N-heteroarylated indoles were prepared by coupling indoles with various heteroaryl halides within 1 h. The selective reactivity of bromoindole with aryl iodide provided N-aryl bromoindoles, which could be useful intermediates for palladium-catalyzed Heck and Suzuki coupling reactions