- A Biphilic Phosphetane Catalyzes N-N Bond-Forming Cadogan Heterocyclization via PIII/PV = O Redox Cycling
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A small-ring phosphacycle, 1,2,2,3,4,4-hexamethylphosphetane, is found to catalyze deoxygenative N-N bond-forming Cadogan heterocyclization of o-nitrobenzaldimines, o-nitroazobenzenes, and related substrates in the presence of hydrosilane terminal reductant. The reaction provides a chemoselective catalytic synthesis of 2H-indazoles, 2H-benzotriazoles, and related fused heterocyclic systems with good functional group compatibility. On the basis of both stoichiometric and catalytic mechanistic experiments, the reaction is proposed to proceed via catalytic PIII/PV = O cycling, where DFT modeling suggests a turnover-limiting (3+1) cheletropic addition between the phosphetane catalyst and nitroarene substrate. Strain/distortion analysis of the (3+1) transition structure highlights the controlling role of frontier orbital effects underpinning the catalytic performance of the phosphetane.
- Nykaza, Trevor V.,Harrison, Tyler S.,Ghosh, Avipsa,Putnik, Rachel A.,Radosevich, Alexander T.
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supporting information
p. 6839 - 6842
(2017/05/29)
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- Evaluation of antibacterial activity of some Schiff bases
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From 4-amino phenol, some Schiff bases were synthesized. By IR and NMR spectral data, the structural characterization of these synthesized compounds were done. The antibacterial activity of all these synthesized Schiff bases was studied against B. cereus-ATCC 11778, P. aero-ATCC 27853, E. coli-ATCC 25922, K pneu-NCIM 2719 and 5. aureus-ATCC 25923, by agar ditch method in dimethyl formamide and dimethyl sulfoxide. It is observed that antibacterial activity depends on the molecular structure of Schiff base, solvent used and bacterial strain under consideration. Out of two solvents studied, dimethyl formamide is proved to be best and salicylaldehyde as side chain to 4-amino phenol could be used as lead molecule in drug designing i.e. in inhibiting above bacterial strains.
- Baluja, Shipra,Parikh, Jigna,Chanda, Sumitra,Vaishnani
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experimental part
p. 1338 - 1342
(2010/08/05)
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