1022975-57-0Relevant articles and documents
A highly efficient copper and ligand free protocol for the room temperature Sonogashira reaction
Gogoi, Ankur,Dewan, Anindita,Bora, Utpal
, p. 16 - 19 (2015)
A mild and efficient catalytic system based on PdCl2 and Na2SO4 has been developed for the Sonogashira reaction of aryl iodides at room temperature. The system provides a simple route to obtain polyfunctional alkynes under ligand and copper free conditions. The procedure is equally efficient for aliphatic alkynes and aryl bromides. This journal is
Agro waste derived nanosilica supported Pd(ll) complex: A protocol for copper free Sonogashira reaction in water
Gogoi, Rajjyoti,Saikia, Rituraj,Borah, Geetika
, p. 80 - 88 (2019/07/04)
A palladium (II) complex immobilized onto nanosilica(Pd-imine@nanoSiO2) has been developed and evaluated as a highly efficient, retrievable catalyst for carbon-carbon triple bond activation reactions between aryl halides and terminal alkynes. Nanosilica has been derived from rice husk by simple and eco-compatible methodology. The catalyst has been extensively characterized by techniques such as FT-IR, UV–vis, powder XRD, XPS, SEM-EDX, thermogravimetric analysis, BET surface area measurement. The catalyst can be reused for five consecutive runs without compromising much with the activity. Easy preparation, its long shelf life, air-stability, wide substrate scope, ‘in water’ reactions, easy separability and good recyclability make it an ideal system for Sonogashira cross-coupling reaction. Moreover, various alkyne substrates were efficiently cross-coupled with a broad range of aryl iodides and aryl bromides to afford diaryl alkynes, providing improved yields with low catalyst loading in water. This protocol is also suitable for aliphatic alkynes.
Supramolecularly engineered perylene bisimide assemblies exhibiting thermal transition from columnar to multilamellar structures
Yagai, Shiki,Usui, Mari,Seki, Tomohiro,Murayama, Haruno,Kikkawa, Yoshihiro,Uemura, Shinobu,Karatsu, Takashi,Kitamura, Akihide,Asano, Atsushi,Seki, Shu
supporting information; experimental part, p. 7983 - 7994 (2012/06/30)
Perylene 3,4:9,10-tetracarboxylic acid bisimide (PBI) was functionalized with ditopic cyanuric acid to organize it into complex columnar architectures through the formation of hydrogen-bonded supermacrocycles (rosette) by complexing with ditopic melamines possessing solubilizing alkoxyphenyl substituents. The aggregation study in solution using UV-vis and NMR spectroscopies showed the formation of extended aggregates through hydrogen-bonding and π-π stacking interactions. The cylindrical fibrillar nanostructures were visualized by microscopic techniques (AFM, TEM), and the formation of lyotropic mesophase was confirmed by polarized optical microscopy and SEM. X-ray diffraction study revealed that a well-defined hexagonal columnar (Colh) structure was formed by solution-casting of fibrillar assemblies. All of these results are consistent with the formation of hydrogen-bonded PBI rosettes that spontaneously organize into the Col h structure. Upon heating the Colh structure in the bulk state, a structural transition to a highly ordered lamellar (Lam) structure was observed by variable-temperature X-ray diffraction, differential scanning calorimetry, and AFM studies. IR study showed that the rearrangement of the hydrogen-bonding motifs occurs during the structural transition. These results suggest that such a striking structural transition is aided by the reorganization in the lowest level of self-organization, i.e., the rearrangement of hydrogen-bonded motifs from rosette to linear tape. A remarkable increase in the transient photoconductivity was observed by the flash-photolysis time-resolved microwave conductivity (FP-TRMC) measurements upon converting the Colh structure to the Lam structure. Transient absorption spectroscopy revealed that electron transfer from electron-donating alkoxyphenyl groups of melamine components to electron-deficient PBI moieties takes place, resulting in a higher probability of charge carrier generation in the Lam structure compared to the Colh structure.
