4714-64-1Relevant academic research and scientific papers
Half-sandwich (η5-Cp?)Rh(iii) complexes of pyrazolated organo-sulfur/selenium/tellurium ligands: Efficient catalysts for base/solvent free C-N coupling of chloroarenes under aerobic conditions
Joshi, Raj Kumar,Sharma, Charu,Sharma, Kamal Nayan,Srivastava, Avinash Kumar
supporting information, p. 3599 - 3606 (2020/06/10)
Three new pyrazolated chalcogenoether ligated Rh(iii) half-sandwich complexes (1-3) were synthesised by the thermal reaction of chalcogenoether (S, Se and Te) substituted 1H-pyrazole ligands (L1-L3) and [(η5-C5Me5)RhCl]2 in methanol. The complexes were fully characterised by various spectroscopic techniques, and the molecular structures of complexes 1 and2 were also established through single crystal X-ray crystallographic analysis, which indicates a pseudo-octahedral half-sandwich piano-stool geometry around the rhodium metal. All three complexes were found to be thermally stable and insensitive towards air and moisture. One mol% of Rh(iii) complexes (1-3) along with 10 mol% of Cu(OAc)2 were explored for the Buchwald-Hartwig type C-N coupling reactions of amine and aryl chloride. Good to excellent yields (89-92%) of the coupling products were obtained with seleno- and thio-ether functionalised pyrazolated Rh(iii) complexes (1 and 2), while an average yield (39%) was obtained with the telluro-ether functionalised complex (3). In contrast to the previously reported C-N coupling reactions the present reaction works under solvent- and base-free conditions, and the coupling reaction is accomplished in just 6 h with a high yield of the coupling product. The present methodology was also found to be efficient for a wide variety of functionalised aryl halides, and aliphatic or aromatic amines (1° and 2°). Moreover, the reaction also enables the C-N coupling of electron-withdrawing substrates and base-sensitive functionalities.
Cp*Co(iii) and Cu(OAc)2bimetallic catalysis for Buchwald-type C-N cross coupling of aryl chlorides and amines under base, inert gas & solvent-free conditions
Srivastava, Avinash K.,Sharma, Charu,Joshi, Raj K.
supporting information, p. 8248 - 8253 (2020/12/29)
A strategy involving bimetallic catalysis with a combination of Cp?Co(CO)I2 and Cu(OAc)2 was used for performing Buchwald-type C-N coupling reactions of aryl chlorides with amines. The reactions proceeded at 100 °C to produce excellent yields of many of the desired C-N coupled products, in 4 h, under aerobic reaction conditions. The reactions were shown to run under base-free and solvent-free conditions, enabling this strategy to work efficiently for electron-withdrawing and base-sensitive functionalities. The presented methodology was found to be equally efficient for electron-donating functionalities as well as for primary (1°) and secondary (2°) aromatic and aliphatic amines. Moreover, the products were easily separated through the extractions of the organic aqueous layer, with this process chromatographic separations is not required.
Method of inhibiting neoplastic cells with imidazoquinazoline derivatives
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, (2008/06/13)
A method for inhibiting neoplasia, particularly cancerous and precancerous lesions by exposing the affected cells to imidazoquinazoline derivatives.
Imidazoquinazoline derivatives
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, (2008/06/13)
PCT No. PCT/JP97/03023 Sec. 371 Date Apr. 27, 1998 Sec. 102(e) Date Apr. 27, 1998 PCT Filed Aug. 29, 1997 PCT Pub. No. WO98/08848 PCT Pub. Date Mar. 5, 1998Imidazoquinoline derivatives of the formula (wherein X may be O or S) provide selective cyclic guanosine 3',5' monophosphate (cGMP)-specific phosphodiesterase (PDE) inhibitory activity. The compounds are useful for treating or ameliorating cardiovascular disease such as thrombosis, angina pectoris, hypertension, heart failure and arterial sclerosis, as well as asthma, impotence and the like.
