'Click' generated 1,2,3-triazole based organosulfur/selenium ligands and their Pd(ii) and Ru(ii) complexes: their synthesis, structure and catalytic applications.

1-(2,6-Diisopropylphenyl)-4-(phenylthio/selenomethyl)-1H-1,2,3-triazole (L1/L2) was synthesized by a 'Click' reaction and treated with [Pd(CH3CN)2Cl2] for 5 h or [(η(6)-C6H6)RuCl(μ-Cl)]2 for 8 h (followed by reaction with NH4PF6) at room temperature, resulting in complexes [Pd(L)Cl2] (1 and 2) or [(η(6)-C6H6)Ru(L)Cl]PF6 (3 and 4) (L = L1 or L2), respectively. The four complexes (1-4) and ligands (L1 and L2) were characterized with (1)H, (13)C{(1)H} and (77)Se{(1)H} NMR spectroscopy and high resolution mass spectrometry. The single crystal structures of 1-4 were solved.

Palladacycles of unsymmetrical (N,C⁻,E) (E = S/Se) pincers based on indole: their synthesis, structure and application in the catalysis of Heck coupling and allylation of aldehydes.

Unsymmetrical (N,C,E)-type pincer ligand precursors [ and : E = S/Se] with an indole core were synthesized for the first time by the condensation of 1-(2-phenylsulfanyl/selenylethyl)-1H-indole-3-carbaldehyde with benzyl amine. The synthetic protocols are easy and give good yields (>85%). and on reaction with sodium tetrachloropalladate(ii) in the presence of CH3COONa result in complexes [Pd(/-H)Cl] (/), where they bind in a tridentate (N,C(-),E) mode.

Complexes of (η(6)-benzene)ruthenium(II) with 1,4-bis(phenylthio/seleno-methyl)-1,2,3-triazoles: synthesis, structure and applications in catalytic activation of oxidation and transfer hydrogenation.

1,4-Bis(phenylthio/seleno methyl)-1,2,3-triazoles (L1-L4) synthesized by a 'Click' reaction react with [{(η(6)-C6H6)RuCl(μ-Cl)}]2 and NH4PF6 resulting in complexes [(η(6)-C6H6)RuClL]PF6 (1-4 for L = L1-L4) in which the ligands coordinate in a bidentate mode through S/Se and N of triazole. The CH2EPh (E = S or Se) attached to nitrogen of triazole remains pendent. Ligands and complexes have been authenticated with multinuclei NMR, IR and HR-MS.

Palladium(II)-1-phenylthio-2-arylchalcogenoethane complexes: palladium phosphide nano-peanut and ribbon formation controlled by chalcogen and Suzuki coupling activation.

The ligands PhSCH2CH2EAr (; E = S, Se or Te) and their Pd-complexes [PdLCl2] () have been synthesized and authenticated with their (1)H, (13)C{(1)H}, (77)Se{(1)H} and (125)Te{(1)H} NMR spectra. Single crystal structures of and reveal the geometry of donor atoms around palladium as nearly square planar. Thermolysis of all three complexes in trioctylphosphine (TOP) at 350, 320 and 280 °C, respectively, results in a single phase of crystalline PdP2.

Efficient catalysis of Suzuki-Miyaura C-C coupling reactions with palladium(II) complexes of partially hydrolyzed bisimine ligands: a process important in environment context.

Potentially hexadentante [O(-),N,E:E,N,O(-)] chalcogenated bisimine ligands L1-L3 have been synthesized by reaction of 1,1'-(4,6-dihydroxy-1,3-phenylene)bisethanone with H2N(CH2)2SPh, H2N(CH2)2SePh and H2N(CH2)2TeC6H4-4-OMe respectively. The L1-L3 react with Na2PdCl4 resulting in their partial hydrolysis, which appears to be metal-promoted. Of the two [(CH3)CN(CH2)2EAr] fragments of L1-L3, one is converted to (CH3)CO and H2N(CH2)2EAr eliminated.

Organoselenium ligands in catalysis.

Organoselenium ligands are building blocks of several transition metal complexes which catalyze various organic reactions efficiently in solution. In this review the survey of developments pertaining to the designing of such complexes (along with their Se-ligands), and their uses as catalysts for various organic reactions has been presented with critical analysis of present status of the subject. Undoubtedly a new family of catalysts or their precursors has been generated by organoselenium ligands.