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Sukbok Chang - One of the best experts on this subject based on the ideXlab platform.
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direct c h Amidation of benzoic acids to introduce meta and para amino groups by tandem decarboxylation
Chemistry: A European Journal, 2015Co-Authors: Donggun Lee, Sukbok ChangAbstract:The Ir-catalyzed mild CH Amidation of benzoic acids with sulfonyl azides was developed to give reactions with high efficiency and functional-group compatibility. Subsequent protodecarboxylation of ortho-amidated benzoic acid products afforded meta- or para-substituted (N-sulfonyl)aniline derivatives, the latter being inaccessible by other CH functionalization approaches. The decarboxylation step was compatible with the Amidation conditions, enabling a convenient one-pot, two-step process.
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iridium catalyzed intermolecular Amidation of sp3 c h bonds late stage functionalization of an unactivated methyl group
Journal of the American Chemical Society, 2014Co-Authors: Taek Kang, Donggun Lee, Zhen Wang, Youngchan Kim, Sukbok ChangAbstract:Reported herein is the iridium-catalyzed direct Amidation of unactivated sp3 C–H bonds. With sulfonyl and acyl azides as the amino source, the Amidation occurs efficiently under mild conditions over a wide range of unactivated methyl groups with high functional group tolerance. This procedure can be successfully applied for the direct introduction of an amino group into complex compounds and thus can serve as a powerful synthetic tool for late-stage C–H functionalization.
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iridium catalyzed direct arene c h bond Amidation with sulfonyl and aryl azides
Journal of Organic Chemistry, 2013Co-Authors: Donggun Lee, Youngchan Kim, Sukbok ChangAbstract:Iridium-catalyzed direct ortho C–H Amidation of arenes has been shown to work well with sulfonyl- and aryl azides as the nitrogen source. The reaction proceeds efficiently with a broad range of substrates bearing conventional directing groups with excellent functional group compatibility under mild conditions. In addition, substrates forming not only 5- but also 6-membered iridacycle intermediates undergo the C–H Amidation with high selectivity.
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recent advances in the transition metal catalyzed twofold oxidative c h bond activation strategy for c c and c n bond formation
Chemical Society Reviews, 2011Co-Authors: Jaesung Kwak, Sukbok ChangAbstract:The direct functionalization of heterocyclic compounds has emerged as one of the most important topics in the field of metal-catalyzed C–H bond activation due to the fact that products are an important synthetic motif in organic synthesis, the pharmaceutical industry, and materials science. This critical review covers the recent progresses on the regioselective dehydrogenative direct coupling reaction of heteroarenes, including arylation, olefination, alkynylation, and amination/Amidation mainly utilizing transition metal catalysts (113 references).
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cobalt and manganese catalyzed direct amination of azoles under mild reaction conditions and the mechanistic details
Angewandte Chemie, 2010Co-Authors: Jiyoung Kim, Seung Hwan Cho, Jomy Joseph, Sukbok ChangAbstract:independently devel-oped a copper-catalyzed amination and Amidation of azoles,respectively, and they proceed under rather harsh reactionconditions (Scheme 1A, a). More recently, Miura et al.successfully developed a new and milder catalytic protocolfor azole amination using chloroamines instead of the parentamines albeit with a rather limited substrate scope withrespect to the amine (Scheme 1A, b).
Akhila K. Sahoo - One of the best experts on this subject based on the ideXlab platform.
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Sulfoximine Directed Intermolecular o-C–H Amidation of Arenes with Sulfonyl Azides
Organic Letters, 2013Co-Authors: M. Ramu Yadav, Akhila K. SahooAbstract:The Ru(II)-catalyzed intermolecular o-C–H Amidation of arenes in N-benzoylated sulfoximine with sulfonyl azides is demonstrated. The reaction proceeds with broad substrate scope and tolerates various functional groups. Base hydrolysis of the Amidation product provides the anthranilic acid derivatives and methylphenyl sulfoximine (MPS) directing group. This method is successfully employed for the synthesis of HMR 1766.
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sulfoximine directed intermolecular o c h Amidation of arenes with sulfonyl azides
Organic Letters, 2013Co-Authors: Ramu M Yadav, Raja K Rit, Akhila K. SahooAbstract:The Ru(II)-catalyzed intermolecular o-C–H Amidation of arenes in N-benzoylated sulfoximine with sulfonyl azides is demonstrated. The reaction proceeds with broad substrate scope and tolerates various functional groups. Base hydrolysis of the Amidation product provides the anthranilic acid derivatives and methylphenyl sulfoximine (MPS) directing group. This method is successfully employed for the synthesis of HMR 1766.
Chi Ming Che - One of the best experts on this subject based on the ideXlab platform.
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Reaction mechanism and stereoselectivity of ruthenium-porphyrin-catalyzed intramolecular Amidation of sulfamate ester: A DFT computational study
Journal of Organic Chemistry, 2008Co-Authors: Xufeng Lin, Chi Ming Che, David Lee PhillipsAbstract:The reaction mechanism of the ruthenium--porhyrin complex [Ru(por)(CO)]-catalyzed intramolecular C-H bond Amidation was examined using density functional theory (DFT) calculations. The metal-nitrene reactive intermediate, Ru(por)(CO)-NSO3R1 (R1 = 1-methylclohexl-methyl) was found to be highly favorable to generate in terms of the free energy profile from the reaction of the starting materials. Ru(por)(CO)-NSO3R1 may exist in both singlet and triplet states since they are close in energy. In each state, six C-H bond Amidation reaction pathways were characterized structurally and energetically. The predicted most probable diastereomeric product out of the four possible diasteromeric products examined in the calculations for the Amidation reactions agree well with previously reported experimental results.
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intermolecular Amidation of unactivated sp2 and sp3 c h bonds via palladium catalyzed cascade c h activation nitrene insertion
Journal of the American Chemical Society, 2006Co-Authors: Hungyat Thu, Chi Ming CheAbstract:This communication describes the Pd(OAc)2-catalyzed intermolecular Amidation reactions of unactivated sp2 and sp3 C−H bonds using primary amides and potassium persulfate. The substrates containing a pendent oxime or pyridine group were amidated with excellent chemo- and regioselectivities. It is noteworthy that reactive C−X bonds were well-tolerated and a variety of primary amides can be effective nucleophiles for the Pd-catalyzed C−H Amidation reactions. For the reaction of unactivated sp3 C−H bonds, β-Amidation of 1° sp3 C−H bonds versus 2° C−H bonds is preferred. The catalytic reaction is initiated by chelation-assisted cyclopalladation involving C−H bond activation. Preliminary mechanistic study suggested that the persulfate oxidation of primary amides should generate reactive nitrene species, which then reacted with the cyclopalladated complex.
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metalloporphyrin mediated asymmetric nitrogen atom transfer to hydrocarbons aziridination of alkenes and Amidation of saturated c h bonds catalyzed by chiral ruthenium and manganese porphyrins
Chemistry: A European Journal, 2002Co-Authors: Jianglin Liang, Jiesheng Huang, Nianyong Zhu, Chi Ming CheAbstract:Chiral metalloporphyrins [Mn(Por * )(OH)(MeOH)] (1) and [Ru-(Por * )(CO)(EtOH)] (2) catalyze asymmetric aziridination of aromatic alkenes and asymmetric Amidation of benzylic hydrocarbons to give moderate enantiomeric excesses. The mass balance in these nitrogen-atom-transfer processes has been examined. With PhI=NTs as the nitrogen source, the aziridination of styrenes, trans-stilbene, 2-vinylnaphthalene, indene, and 2,2-dimethylchromene catalyzed by complex 1 or 2 resulted in up to 99 % substrate conversions and up to 94% aziridine selectivities, whereas the Amidation of ethylbenzenes, indan, tetralin, 1-, and 2-ethylnaphthalene catalyzed by complex 2 led to substrate conversions of up to 32% and amide selectivities of up to 91 %. Complex 1 or 2 can also catalyze the asymmetric Amidation of 4-methoxyethylbenzene, tetralin, and 2-ethylnaphthalene with "PhI(OAc) 2 + NH 2 SO 2 Me", affording the N-substituted methanesulfonamides in up to 56% ee with substrate conversions of up to 34% and amide selectivities of up to 92%. Extension of the "complex 1 + PhI=NTs" or "complex 1 + PhI(OAc) 2 + NH 2 R (R = Ts, Ns)" Amidation protocol to a steroid resulted in diastereoselective Amidation of cholesteryl acetate at the allylic C-H bonds at C-7 with substrate conversions of up to 49% and amide selectivities of up to 90% (α:β ratio: up to 4.2:1). An aziridination- and Amidation-active chiral bis(tosylimido)ruthenium(VI) porphyrin, [Ru(Por * )(NTs) 2 ] (3), and a ruthenium porphyrin aziridine adduct, [Ru(Por * )-(CO)(TsAz)] (4, TsAz = N-tosyl-2-(4-chlorophenyl)aziridine), have been isolated from the reaction of 2 with PhI=NTs and N-tosyl-2-(4-chlorophenyl)aziridine, respectively. The imidoruthenium porphyrin 3 could be an active species in the aziridination or Amidation catalyzed by complex 2 described above. The second-order rate constants for the reactions of 3 with styrenes, 2-vinylnaphthalene, indene, ethylbenzenes, and 2-ethylnaphthalene range from 3.7-42.5 × 10 - 3 dm 3 mol - 1 s - 1 . An X-ray structure determination of complex 4 reveals an O- rather than N-coordination of the aziridine axial ligand. The fact that the N-tosylaziridine in 4 does not adopt an N-coordination mode disfavors a concerted pathway in the aziridination by a tosylimido ruthenium porphyrin active species.
Steven J Fussell - One of the best experts on this subject based on the ideXlab platform.
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tetramethyl orthosilicate tmos as a reagent for direct Amidation of carboxylic acids
Organic Letters, 2018Co-Authors: Christopher D Braddock, Paul D Lickiss, Ben C Rowley, David Pugh, Teresa Purnomo, Gajan Santhakumar, Steven J FussellAbstract:Tetramethyl orthosilicate (TMOS) is shown to be an effective reagent for direct Amidation of aliphatic and aromatic carboxylic acids with amines and anilines. The amide products are obtained in good to quantitative yields in pure form directly after workup without the need for any further purification. A silyl ester as the putative activated intermediate is observed by NMR methods. Amidations on a 1 mol scale are demonstrated with a favorable process mass intensity.
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Tetramethyl Orthosilicate (TMOS) as a Reagent for Direct Amidation of Carboxylic Acids
2018Co-Authors: Christopher D Braddock, Paul D Lickiss, Ben C Rowley, David Pugh, Teresa Purnomo, Gajan Santhakumar, Steven J FussellAbstract:Tetramethyl orthosilicate (TMOS) is shown to be an effective reagent for direct Amidation of aliphatic and aromatic carboxylic acids with amines and anilines. The amide products are obtained in good to quantitative yields in pure form directly after workup without the need for any further purification. A silyl ester as the putative activated intermediate is observed by NMR methods. Amidations on a 1 mol scale are demonstrated with a favorable process mass intensity
John F Hartwig - One of the best experts on this subject based on the ideXlab platform.
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copper catalyzed intermolecular Amidation and imidation of unactivated alkanes
ChemInform, 2014Co-Authors: Ba L Tran, Matthias Driess, John F HartwigAbstract:The copper-catalyzed Amidation of unactivated alkanes by benzamides, sulfonamides, carbamates, and phthalimides is described.
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copper catalyzed intermolecular Amidation and imidation of unactivated alkanes
Journal of the American Chemical Society, 2014Co-Authors: Ba L Tran, Matthias Driess, John F HartwigAbstract: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 a...
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copper complexes of anionic nitrogen ligands in the Amidation and imidation of aryl halides
Journal of the American Chemical Society, 2008Co-Authors: Jesse W Tye, Zhiqiang Weng, Adam M Johns, Christopher D Incarvito, John F HartwigAbstract:Copper(I) imidate and amidate complexes of chelating N,N-donor ligands, which are proposed intermediates in copper-catalyzed Amidations of aryl halides, have been synthesized and characterized by X-ray diffraction and detailed solution-phase methods. In some cases, the complexes adopt neutral, three-coordinate trigonal planar structures in the solid state, but in other cases they adopt an ionic form consisting of an L2Cu+ cation and a CuX2− anion. A tetraalkylammonium salt of the CuX2− anion in which X = phthalimidate was also isolated. Conductivity measurements and 1H NMR spectra of mixtures of two complexes all indicate that the complexes exist predominantly in the ionic form in DMSO and DMF solutions. One complex was sufficiently soluble for conductance measurements in less polar solvents and was shown to adopt some degree of the ionic form in THF and predominantly the neutral form in benzene. The complexes containing dative nitrogen ligands reacted with iodoarenes and bromoarenes to form products from...
