- Oxidative amidation of benzaldehydes and benzylamines with: N -substituted formamides over a Co/Al hydrotalcite-derived catalyst
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The present work describes a highly efficient synthetic strategy for amides via oxidative coupling of benzaldehydes or benzylamines with N-substituted formamides using a heterogeneous Co/Al hydrotalcite-derived catalyst in the presence of TBHP. A series of Co/Al hydrotalcite-derived catalysts (Cat-2, Cat-3, and Cat-4 with the Co2+/Al3+ molar ratio in the synthesis mixture as 1/1, 2/1 and 3/1) have been prepared by a simple co-precipitation method and characterized using powder XRD, XPS, FEG-SEM, EDS, FT-IR, DTG-TGA and N2 physical adsorption techniques. Among the as-prepared catalysts, Cat-3 exhibited excellent catalytic activity towards the direct amidation of benzaldehydes as well as benzylamines bearing various substituents into the corresponding amides at 100 °C using TBHP as an oxidant. The mechanistic investigation of the amidation reaction revealed that the reaction follows a radical pathway. Furthermore, the catalyst is easily separable and recyclable without considerable loss in catalytic activity.
- Gupta, Shyam Sunder R.,Nakhate, Akhil V.,Rasal, Kalidas B.,Deshmukh, Gunjan P.,Mannepalli, Lakshmi Kantam
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- Direct and Selective C-H Carbamoylation of (Hetero)aromatics with TMSOTf-Activated Carbamoyl Chloride
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Exploiting trimethylsilyltrifluoromethanesulfonate as Lewis acid, (hetero)aromatics underwent regioselective and direct carbamoylation. The method is based on the in situ generation of a highly electrophilic carbamoyl triflate active species.
- Uehara, Ayaka,Olivero, Sandra,Michelet, Bastien,Martin-Mingot, Agnès,Thibaudeau, Sébastien,Du?ach, Elisabet
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supporting information
p. 46 - 49
(2018/11/27)
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- Facile Access to Amides from Oxygenated or Unsaturated Organic Compounds by Metal Oxide Nanocatalysts Derived from Single-Source Molecular Precursors
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Oxidative amidation is a valuable process for the transformation of oxygenated organic compounds to valuable amides. However, the reaction is severely limited by the use of an expensive catalyst and limited substrate scope. To circumvent these limitations, designing a transition-metal-based nanocatalyst via more straightforward and economical methodology with superior catalytic performances with broad substrate scope is desirable. To resolve the aforementioned issues, we report a facile method for the synthesis of nanocatalysts NiO and CuO by the sol-gel-assisted thermal decomposition of complexes [Ni(hep-H)(H2O)4]SO4 (SSMP-1) and [Cu(μ-hep)(BA)]2 (SSMP-2) [hep-H = 2-(2-hydroxylethyl)pyridine; BA = benzoic acid] as single-source molecular precursors (SSMPs) for the oxidative amidation of benzyl alcohol, benzaldehyde, and BA by using N,N-dimethylformamide (DMF) as the solvent and as an amine source, in the presence of tert-butylhydroperoxide (TBHP) as the oxidant, at T = 80 °C. In addition to nanocatalysts NiO and CuO, our previously reported Co/CoO nanocatalyst (CoNC), derived from the complex [CoII(hep-H)(H2O)4]SO4 (A) as an SSMP, was also explored for the aforementioned reaction. Also, we have carefully investigated the difference in the catalytic performance of Co-, Ni-, and Cu-based nanoparticles synthesized from the SSMP for the conversion of various oxygenated and unsaturated organic compounds to their respective amides. Among all, CuO showed an optimum catalytic performance for the oxidative amidation of various oxygenated and unsaturated organic compounds with a broad reaction scope. Finally, CuO can be recovered unaltered and reused for several (six times) recycles without any loss in catalytic activity.
- Mohammad, Akbar,Chandra, Prakash,Ghosh, Topi,Carraro, Mauro,Mobin, Shaikh M.
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p. 10596 - 10608
(2017/09/12)
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