- Method for selective N-methylation of secondary amide
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The invention relates to a method for selective N-methylation of secondary amide. The method is characterized in that the secondary amide is in an organic solvent N, N-dimethyl formamide or dimethyl sulfoxide, trifluoroacetic acid methyl ester serves as a methylation reagent, and reaction is performed in the presence of sodium hydride, potassium tert-butoxide or sodium methylate, so as to obtain aselective N-methylated product. The method has the characteristics that generally a trifluoroacetylation product is produced when the trifluoroacetic acid methyl ester is reacted with amine compounds, however a N-methylated product can be selectively obtained when the trifluoroacetic acid methyl ester is reacted with secondary amide; the method is simple to operate, low in cost, mild in reactionconditions and high in selectivity, and avoids the use of hypertoxic methylation reagents, such as dimethyl sulfate and methyl iodide.
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Paragraph 0011
(2019/03/08)
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- Amide Effects in C?H Activation: Noncovalent Interactions with L-Shaped Ligand for meta Borylation of Aromatic Amides
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A new concept for the meta-selective borylation of aromatic amides is described. It has been demonstrated that while esters gave para borylations, amides lead to meta borylations. For achieving high meta selectivity, an L-shaped bifunctional ligand has been employed and engages in an O???K noncovalent interaction with the oxygen atom of the moderately distorted amide carbonyl group. This interaction provides exceptional control for meta C?H activation/borylation.
- Bisht, Ranjana,Hoque, Md Emdadul,Chattopadhyay, Buddhadeb
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supporting information
p. 15762 - 15766
(2018/11/10)
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- Domino Pd0-Catalyzed C(sp3)–H Arylation/Electrocyclic Reactions via Benzazetidine Intermediates
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The Pd0-catalyzed C(sp3)-H arylation of 2-bromo-N-methylanilides leads to unstable benzazetidine intermediates that rearrange to benzoxazines through 4π electrocyclic ring-opening and 6π electrocyclization. The introduction of a bulky, non-activatable amide group on the nitrogen atom was key to favor the challenging reductive elimination step and disfavor undesired reaction pathways.
- Rocaboy, Ronan,Dailler, David,Zellweger, Florian,Neuburger, Markus,Salomé, Christophe,Clot, Eric,Baudoin, Olivier
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p. 12131 - 12135
(2018/09/11)
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- A convenient synthesis of Trifluoroacetamides from sodium trifluoroacetate and amines
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Trifluoroacetamides were prepared readily by reaction of sodium trifluoroacetate with triphenylphosphine di-iodide and amines consecutively under mild conditions with good yields.
- Zhou, Qi-Zhong,Chen, Zhen-Chu
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p. 3189 - 3194
(2007/10/03)
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- Phosphorus in organic synthesis. Acyloxyphosphonium salts as chemoselective acylating reagents
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Acyloxytriphenylphosphonium salts 1 prepared in situ react with a variety of aminophenols to give the corresponding amides in excellent yields. At -25°N-acylated products are formed exclusively, whereas 0°some O-acylated products are observed. 1 is also a
- Froyen, Paul
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p. 5359 - 5362
(2007/10/03)
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- Re-evaluation of Cyclodextrin as a Model of Chymotrypsin: Acceleration and Inhibition of Tertiary Anilide Hydrolysis
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The hydrolysis of p-nitro-N-methyltrifluoroacetanilide (1), p-chloro-N-methyltrifluoroacetanilide (2), N-methyltrifluoroacetanilide (3), and p-methoxy-N-methyltrifluoroacetanilide (4) in the presence and absence of α- and β-cyclodextrin has been studied at 7.5 pH 10.6.For 1-3, cyclodextrin (CD) exhibits simple Michaelis-Menten saturation kinetics, with no evidence for reaction via other than 1:1 CD-substrate complexes.The behavior of CD with 4 is more complex.Moreover, CD catalyzes the hydrolysis of 1 but inhibits the hydrolysis of 2-4 across the pH range studied.The nature of the buffer catalysis in the absence of CD, exhibited in the hydrolysis of 1, also shows marked differences with that exhibited by 2-4.The data are almost simply interpreted by a mechanism in which CD accelerates formation of a tetrahedral intermediate 5; in the case of 1, the rate of breakdown of this intermediate is greater than the rate of buffer-catalyzed breakdown of the hydrolysis intermediate.The CD cavity may provide an environment complementary to the transition state for expulsion of the anilide leaving group.These results are compared with the previously reported effects of CDs on trifluoroacetanilide and phenyl ester hydrolysis and proposal of CD as a model of chymotrypsin.
- Palmer, David R. J.,Buncel, Erwin,Thatcher, Gregory R. J.
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p. 5286 - 5291
(2007/10/02)
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- Electrolytic Transformation of Fluoroorganic Compounds. 3. Highly Regioselective Anodic Methoxylation of N-(2,2,2-trifluoroethyl)amines
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Anodic methoxylation of N-alkyl-N-(2,2,2-trifluoroethyl)anilines and N-(2,2,2-trifluoroethyl)diphenylamine places the methoxy group in the α-position (toward the trifluoromethyl group); these products are useful building blocks for the construction of a c
- Fuchigami, Toshio,Nakagawa, Yuuki,Nonaka, Tsutomu
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p. 5489 - 5491
(2007/10/02)
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- SUBSTITUENT EFFECT TREATMENT OF INTERACTIONS BETWEEN CONTIGUOUS FUNCTIONALITIES. IV. RESTRAINT TO PHENYL-NITROGEN CONJUGATIVE INTERACTION IN N-FUNCTIONALIZED N-METHYLANILINES
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13C shifts at the para position in PhN(Me)X for 17 different substituents X serve as monitors for investigating, in correlative analysis, the nature and the extent of interactions occurring between the substituent X and the N-Me cavity.For the majority of substituent, X, partitioning of the nitrogen electron pair between the phenyl and the substituent is partially hampered because of the non-zero twist angle between the planes containing the phenyl ring and the Me-N-X fragment.As a consequence, relative to PhNHX, the interactions between the cavity and the substituents are increased in intensity, especially their mesomeric component, and, at the same time, para-13C shifts are displaced toward lower field.Evidence is also provided that possible H-bonding by the NH cavity of PhNHX with dimethyl sulphoxide does not appreciably influence the substituent electron demand determined previously.
- Bradamante, Silvia,Colombo, Silvana,Pagani, Giorgio A.,Roelens, Stefano
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p. 357 - 364
(2007/10/02)
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