121-81-3Relevant articles and documents
Bifunctional water activation for catalytic hydration of organonitriles
Daw, Prosenjit,Sinha, Arup,Rahaman, S. M. Wahidur,Dinda, Shrabani,Bera, Jitendra K.
, p. 3790 - 3797 (2012)
Treatment of [Rh(COD)(μ-Cl)]2 with excess tBuOK and subsequent addition of 2 equiv of PIN?HBr in THF afforded [Rh(COD)(κC2-PIN)Br] (1) (PIN = 1-isopropyl-3-(5,7-dimethyl-1, 8-naphthyrid-2-yl)imidazol-2-ylidene, COD = 1,5-cyclooctadiene). The X-ray structure of 1 confirms ligand coordination to "Rh(COD)Br" through the carbene carbon featuring an unbound naphthyridine. Compound 1 is shown to be an excellent catalyst for the hydration of a wide variety of organonitriles at ambient temperature, providing the corresponding organoamides. In general, smaller substrates gave higher yields compared with sterically bulky nitriles. A turnover frequency of 20 000 h-1 was achieved for the acrylonitrile. A similar Rh(I) catalyst without the naphthyridine appendage turned out to be inactive. DFT studies are undertaken to gain insight on the hydration mechanism. A 1:1 catalyst-water adduct was identified, which indicates that the naphthyridine group steers the catalytically relevant water molecule to the active metal site via double hydrogen-bonding interactions, providing significant entropic advantage to the hydration process. The calculated transition state (TS) reveals multicomponent cooperativity involving proton movement from the water to the naphthyridine nitrogen and a complementary interaction between the hydroxide and the nitrile carbon. Bifunctional water activation and cooperative proton migration are recognized as the key steps in the catalytic cycle.
Single-electron transfer in aromatic nucleophilic substitution on dinitrobenzonitriles
Bacaloglu, Radu,Blaskó, Andrei,Bunton, Clifford A.,Ortega, Francisco,Zucco, César
, p. 7708 - 7718 (1992)
Reaction of OH- with 3,5-dinitrobenzonitrile in water or water-DMSO gives a mixture of unproductive 2- and 4-Meisenheimer complexes that equilibriate and eventually form 3,5-dinitrobenzamide and finally the benzoate ion. The corresponding reaction of 2,4-dinitrobenzonitrile gives the 5-Meisenheimer complex and then a mixture of 2,4-dinitrobenzamide and 2,4-dinitrophenoxide ion. The ratio amide:phenoxide ion increases with increasing [OH-]. These reactions appear to involve formation of charge-transfer complexes of the radical anion of the substrate and ?OH which collapse to give Meisenheimer complexes and final products. The rate constants of the various reaction steps can be estimated by simulation based on relaxation theory, which also fits the product mixture from 2,4-dinitrobenzonitrile. This reaction scheme is consistent with observations of exchange of arene hydrogen and of extensive broadening of 1H NMR signals of the substrates during reaction.
A mild and selective Cu(II) salts-catalyzed reduction of nitro, azo, azoxy, N-aryl hydroxylamine, nitroso, acid halide, ester, and azide compounds using hydrogen surrogacy of sodium borohydride
Kalola, Anirudhdha G.,Prasad, Pratibha,Mokariya, Jaydeep A.,Patel, Manish P.
supporting information, p. 3565 - 3589 (2021/10/12)
The first mild, in situ, single-pot, high-yielding well-screened copper (II) salt-based catalyst system utilizing the hydrogen surrogacy of sodium borohydride for selective hydrogenation of a broad range of nitro substrates into the corresponding amine under habitancy of water or methanol like green solvents have been described. Moreover, this catalytic system can also activate various functional groups for hydride reduction within prompted time, with low catalyst-loading, without any requirement of high pressure or molecular hydrogen supply. Notably, this system explores a great potential to substitute expensive traditional hydrogenation methodologies and thus offers a greener and simple hydrogenative strategy in the field of organic synthesis.
Direct and facile synthesis of primary amides from carboxylic acids via acyl isocyanate intermediates using mukaiyama reagent
Azadi, Roya,Motamedpoor, Zahra
, p. 801 - 804 (2018/09/26)
A very simple and efficient procedure for the preparation of primary amides is described from carboxylic acids using Mukaiyama reagent/KNCO in aqueous acetonitrile. Availability of the reagents, simplicity, and easy workup of the reaction crude make this method attractive for organic chemists.
