13481-81-7Relevant academic research and scientific papers
New Bidentate N-Sulfonyl-Substituted Aromatic Amines as Chelate Ligand Backbones: Pd Catalyst Generation in C-C Coupling via in Situ and Precatalyst Modes
Oloyede, Hammed Olawale,Akong Akong, Raymond,Woods, Joseph Anthony Orighomisan,G?rls, Helmar,Plass, Winfried,Eseola, Abiodun Omokehinde
, p. 101 - 110 (2020/07/28)
A series of six new, bidentate ligands based on N-(2-(R-sulfonamido)benzyl)R-sulfonamide have been isolated as dianionic or monoanionic chelators via condensation of 2-(aminomethyl)aniline with sulfonyl chloride reagents; R = methyl (1 and 1′), tolyl (2 and 2′), 2,4,6-Trimethylphenyl (3), or 2,4,6-Triisopropylphenyl (4). Complexes of ligands 2-4 reacted at room temperature with palladium(ii) acetate in the presence of various monodentate N-donor co-ligands to form complexes Pd2(2dmap), Pd2′(OAc.py), Pd3(2acn), Pd3(2py), Pd4(2acn), and Pd4(2py), which were structurally confirmed by three X-ray crystal analyses. Results of catalysis studies in water showed high turnover frequencies and yields of up to 98 % within 10 min and at 0.2 mol-% palladium catalyst loading. Relative to ligand-free catalysis in the presence of only Pd(OAc)2, the ligand-supported palladium species clearly possess positive catalytic advantage. Furthermore, Suzuki coupling efficiencies by 1: 1 'Pd(OAc)2 + ligand' yielded notably better outcomes than for the 1: 2 'Pd(OAc)2 + ligand' in situ catalyst generation, which reveals that coordinative saturation is undesirable. The size of the complementing monodentate co-ligand was observed to influence the catalytic efficiency such that bulkier co-ligands consistently yielded improved turnover frequency values, which leads to the conclusion that steric repulsion between the synthesised ligands and the bulkier co-ligands aided the generation of vacant coordination sites for the more active complexes. Moderate Heck coupling activity was recorded for the complexes and better activities appear to correlate with moderate bulkiness of ligand 3.
SYNTHESIS OF 2,3,5,6-TETRAHYDRO-1H,4H,11cH-3a,6a,11b-TRIAZABENZANTHRACENE (5) AND X-RAY CRYSTAL STRUCTURE DETERMINATIONS OF (5), HEXAHYDRO-1H,4H,7H,9bH-3a,6a,9a-TRIAZAPHENALENE (1), BENZO-1,5,9-TRIAZADODECANE N,N',N''-TRITOSYLAMIDE, AND OF 1,5,9-TRIAZADODECANE N,N'N''-TRITOSYLAMID
Beddoes, Roy L.,Edwards, W. D.,Joule, J. A.,Mills, O. S.,Street, J. D.
, p. 1903 - 1920 (2007/10/02)
The synthesis of 2,3,5,6-tetrahydro-1H,4H,11cH-3a,6a,11b-triazabenzanthracene (5) is described.X-ray crystal structure determinations on hexahydro-1H,4H,7H,9bH-3a,6a,9a-triazaphenalene (1) and its benzoanaloque (5) show them to adopt differing conformations; the reasons for this are discussed.
