- Method for synthesizing amide compounds by using N-Boc amide as substrate
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The invention relates to a method for synthesizing amide compounds by using N-Boc amide as a substrate. According to the method, N-Boc amide and various amine compounds are subjected to an intermolecular nucleophilic substitution reaction in an organic solvent so as to efficiently prepare various amide compounds. The method has the advantages of mild reaction conditions, simple and convenient operation, high yield and good functional group compatibility.
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Paragraph 0238-0246
(2020/01/12)
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- Amidation via ligand-free direct oxidative C(sp3)-H/N[sbnd]H coupling with Cu-CPO-27 metal-organic framework as a recyclable heterogeneous catalyst
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A copper-based metal-organic framework Cu-CPO-27 was synthesized, and used as a recyclable catalyst for the amidation of unactivated alkanes by benzamides via direct oxidative C(sp3)-H/N[sbnd]H coupling under ligand-free conditions. Using a catalytic amount of the Cu-CPO-27 for the transformation, high yields of N-cyclohexyl benzamides were achieved. The Cu-CPO-27 was more catalytically active than other Cu-MOFs such as Cu3(BTC)2, Cu(BDC), Cu(EDB), Cu2(BPDC)2(BPY), Cu2(BDC)2(DABCO), and Cu2(EDB)2(BPY). The Cu-CPO-27 also exhibited advantages as compared to several copper-based salts, including Cu(OAc)2, CuCl2, CuBr, CuI, CuCl, Cu(NO3)2, and CuSO4. The Cu-CPO-27 catalyst could be reused several times for the amidation transformation while its catalytic activity was not decreased significantly. To the best of our knowledge, the amidation of unactivated alkanes by benzamides via direct oxidative C(sp3)-H/N[sbnd]H coupling was not previously performed under heterogeneous catalysis conditions.
- Hoang, Thanh T.,Nguyen, Hanh T.H.,Le, Tien T.,Le, Dung T.,Truong, Thanh,Phan, Nam T.S.
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p. 8241 - 8251
(2016/11/23)
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- Copper-catalyzed intermolecular amidation and imidation of unactivated alkanes
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We report a set of rare copper-catalyzed reactions of alkanes with simple amides, sulfonamides, and imides (i.e., benzamides, tosylamides, carbamates, and phthalimide) to form the corresponding N-alkyl products. The reactions lead to functionalization at secondary C-H bonds over tertiary C-H bonds and even occur at primary C-H bonds. [(phen)Cu(phth)] (1-phth) and [(phen)Cu(phth)2] (1-phth2), which are potential intermediates in the reaction, have been isolated and fully characterized. The stoichiometric reactions of 1-phth and 1-phth2 with alkanes, alkyl radicals, and radical probes were investigated to elucidate the mechanism of the amidation. The catalytic and stoichiometric reactions require both copper and tBuOOtBu for the generation of N-alkyl product. Neither 1-phth nor 1-phth2 reacted with excess cyclohexane at 100 C without tBuOOtBu. However, the reactions of 1-phth and 1-phth2 with tBuOOtBu afforded N-cyclohexylphthalimide (Cy-phth), N-methylphthalimide, and tert-butoxycyclohexane (Cy-OtBu) in approximate ratios of 70:20:30, respectively. Reactions with radical traps support the intermediacy of a tert-butoxy radical, which forms an alkyl radical intermediate. The intermediacy of an alkyl radical was evidenced by the catalytic reaction of cyclohexane with benzamide in the presence of CBr4, which formed exclusively bromocyclohexane. Furthermore, stoichiometric reactions of [(phen)Cu(phth)2] with tBuOOtBu and (Ph(Me)2CO) 2 at 100 C without cyclohexane afforded N-methylphthalimide (Me-phth) from β-Me scission of the alkoxy radicals to form a methyl radical. Separate reactions of cyclohexane and d12-cyclohexane with benzamide showed that the turnover-limiting step in the catalytic reaction is the C-H cleavage of cyclohexane by a tert-butoxy radical. These mechanistic data imply that the tert-butoxy radical reacts with the C-H bonds of alkanes, and the subsequent alkyl radical combines with 1-phth2 to form the corresponding N-alkyl imide product.
- Tran, Ba L.,Li, Bijie,Driess, Matthias,Hartwig, John F.
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supporting information
p. 2555 - 2563
(2014/03/21)
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- Stereoretentive copper(II)-catalyzed ritter reactions of secondary cycloalkanols
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A Ritter-like coupling reaction of cyclic alcohols and both aryl and alkyl nitriles to form amides catalyzed by copper(II) triflate is described. These reactions proceed in good yields under mild and often solvent-free conditions. With 2-and 3-substituted
- Al-Huniti, Mohammed H.,Lepore, Salvatore D.
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supporting information
p. 3071 - 3076
(2014/03/21)
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- A thermal fragmentation of 1,2,4-oxadiazole-4-oxides to nitriles and nitrosocarbonyls
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1,2,4-Oxadiazole-4-oxides undergo clean thermal cleavage in refluxing chlorobenzene or xylene to nitriles and nitrosocarbonyl intermediates, which are either trapped with suitable olefins to afford ene adducts or dimerize and rearrange to anhydrides. (C) 2000 Elsevier Science Ltd.
- Quadrelli,Campari,Mella,Caramella
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p. 2019 - 2022
(2007/10/03)
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