C–O Bond Activation by Nickel–Palladium Hetero-Bimetallic Nanoparticles for Suzuki–Miyaura Reaction of Bioactive Heterocycle-Tethered Sterically Hindered Aryl Carbonates
作者:Priyank Purohit、Kapileswar Seth、Asim Kumar、Asit K. Chakraborti
DOI:10.1021/acscatal.6b02912
日期:2017.4.7
Ni–Pd binary nanoclusters are reported for the activation of the C–O bond for Suzuki–Miyaura cross-coupling of bioactive heterocycle-tethered stericallyhindered aryl carbonates with aryl boronic acids. The reaction does not take place in the presence of either the Pd or Ni salts/complexes or the individual Pd or Ni nanoparticles, indicating ensembling cooperativity between the Pd and Ni nanoparticles
Benzoxazole or Benzothiazole as an Innate Directing Group for Palladium- and Ruthenium-Catalyzed Complementary C–H Arylation: Functionalization of Biorelevant Heterocyclic Scaffolds
were used as innate directing groups for Pd(II)- and Ru(II)-catalyzed C–H arylation of the biorelevant heterocycles 2-arylbenzoxazole and 2-arylbenzothiazole with diverse iodoarenes; palladium and ruthenium catalysis could be used complementarily. The use of σ-donor ligands, such as N,N-dimethylacetamide in the Pd(II) catalytic cycle, and σ-donor/π-acceptor ligands, such as PPh3 in the Ru(II) catalytic
2-(2-Arylphenyl)benzoxazole As a Novel Anti-Inflammatory Scaffold: Synthesis and Biological Evaluation
作者:Kapileswar Seth、Sanjeev K. Garg、Raj Kumar、Priyank Purohit、Vachan S. Meena、Rohit Goyal、Uttam C. Banerjee、Asit K. Chakraborti
DOI:10.1021/ml400500e
日期:2014.5.8
The 2-(2-arylphenyl)benzoxazole moiety has been found to be a new and selective ligand for the enzyme cyclooxygenase-2 (COX-2). The 2-(2-arylphenyl)benzoxazoles 3a-m have been synthesized by Suzuki reaction of 2-(2-bromophenyl)benzoxazole. Further synthetic manipulation of 3f and 3i led to 3o and 3n, respectively. The compounds 3g, 3n, and 3o selectively inhibited COX-2 with selectivity index of 3n much better than that of the COX-2 selective NSAID celecoxib. The in vivo anti-inflammatory potency of 3g and 3n is comparable to that of celecoxib and the nonselective NSAID diclofenac at two different doses, and 30 showed better potency compared to these clinically used NSAIDs.