6830-83-7Relevant articles and documents
CARBANION-MEDIATED OXIDATIVE DEPROTECTION OF NON-ENOLIZABLE BENZYLATED AMINES
Williams, Robert M.,Kwast, Ewa
, p. 451 - 454 (1989)
Treatment of non-enolizable N-benzyl or N-para-methoxybenzyl amides with butyllithium generates the corresponding benzylic carbanions that can be oxidized with either molecular oxygen or MoOPH; the resulting hemi-aminals suffer loss of the corresponding aldehyde generating te products of amide dealkylation.
Direct synthesis of amides from nonactivated carboxylic acids using urea as nitrogen source and Mg(NO3)2or imidazole as catalysts
Blacker, A. John,Chhatwal, A. Rosie,Lomax, Helen V.,Marcé, Patricia,Williams, Jonathan M. J.
, p. 5808 - 5818 (2020/06/21)
A new method for the direct synthesis of primary and secondary amides from carboxylic acids is described using Mg(NO3)2·6H2O or imidazole as a low-cost and readily available catalyst, and urea as a stable, and easy to manipulate nitrogen source. This methodology is particularly useful for the direct synthesis of primary and methyl amides avoiding the use of ammonia and methylamine gas which can be tedious to manipulate. Furthermore, the transformation does not require the employment of coupling or activating agents which are commonly required.
Utilizing Carbonyl Coordination of Native Amides for Palladium-Catalyzed C(sp3)?H Olefination
Park, Hojoon,Li, Yang,Yu, Jin-Quan
supporting information, p. 11424 - 11428 (2019/07/17)
PdII-catalyzed C(sp3)?H olefination of weakly coordinating native amides is reported. Three major drawbacks of previous C(sp3)?H olefination protocols, 1) in situ cyclization of products, 2) incompatibility with α-H-containing substrates, and 3) installation of exogenous directing groups, are addressed by harnessing the carbonyl coordination ability of amides to direct C(sp3)?H activation. The method enables direct C(sp3)?H functionalization of a wide range of native amide substrates, including secondary, tertiary, and cyclic amides, for the first time. The utility of this process is demonstrated by diverse transformations of the olefination products.
Ruthenium-catalyzed reduction of N-alkoxy- and N-hydroxyamides
Fukuzawa, Hiroko,Ura, Yasuyuki,Kataoka, Yasutaka
, p. 3643 - 3648 (2011/12/02)
A ruthenium-catalyzed reduction of N-alkoxy- and N-hydroxyamides was found to afford corresponding amides in good to high yields. A simple RuCl 3/Zn-Cu/alcohol system, without the addition of any other ligands, exhibited a high catalytic activity, and therefore the present reaction does not require a stoichiometric amount of metals or metal complexes as reductants. When β-substituted-α,β-unsaturated N-methoxyamides were employed as substrates, concurrent hydrogenation of the olefin moiety proceeded slowly with deprotection of the methoxy group. In the reduction of N-hydroxyamides, the alcoholic solvent was found to function as a hydrogen donor.
Lawesson's reagent for direct thionation of hydroxamic acids: Substituent effects on LR reactivity
Przychodzen, Witold
, p. 676 - 684 (2007/10/03)
To explore the generality and scope of direct thionation of hydroxamic acids (HAs), the reaction of various structurally diverse HAs with Lawesson's reagent was investigated. The yield of thiohydroxamic acid (THAs) is poor when HAs possess bulky acyl and/or N-substituents, acidic α-hydrogen atoms, or an N-phenyl ring. THAs yields were correlated with Brown sigma parameter. The relative rates of two subsequent processes kT2 and kR2 were also measured. Correlation was also found for methine proton chemical shifts of N-isopropyl benzothiohydroxamic acids.
Encapsulated reagents for nitrosation
Zyryanov, Grigory V.,Rudkevich, Dmitry M.
, p. 1253 - 1256 (2007/10/03)
(Matrix presented) A novel class of stable, mild, and size-shape-selective nitrosating agents for secondary amides is introduced. These are based on reversible entrapment and release of reactive nitrosonium species by calix[4]arenes. The NO+ encapsulation controls the reaction selectivity.
beta-scission of the N-O bond in alkyl hydroxamate radicals: a fast radical trap.
Wu,Begley
, p. 1345 - 1348 (2007/10/03)
[reaction--see text ] The rate of the beta-scission of the N-O bond in the alkyl hydroxamate radical is faster than 2 x 10(8) s(-)(1). This reaction may be useful as a radical trap.
Reductive deprotection of allyl, benzyl and sulfonyl substituted alcohols, amines and amides using a naphthalene-catalysed lithiation
Alonso, Emma,Ramon, Diego J.,Yus, Miguel
, p. 14355 - 14368 (2007/10/03)
The reaction of different protected alcohols, amines and amides with lithium and a catalytic amount of naphthalene (4 mol %) in THF at low temperature leads to their deprotection under very mild reaction conditions, the process being in many cases chemoselective.
Cationic Carbon to Nitrogen Rearrangements in the Reactions of N-(Sulfonyloxy)amines with Aldehydes
Hoffman, Robert V.,Salvador, James M.
, p. 4487 - 4490 (2007/10/02)
A series of aromatic and aliphatic aldehydes was reacted with N-((p-nitrobenzenesulfonyl)oxy)methylamine in chloroform.Products resulting from both carbon migration and hydride migration to nitrogen were isolated.The ratios of carbon to hydride migration products were used to clarify the reaction mechanism.The results support a two-step process in which cationic carbon to nitrogen rearrangements is rate determining.
A New Mode of Reactivity of N-Methoxy-N-methylamides with Strongly Basic Reagents
Graham, Samuel L.,Scholz, Thomas H.
, p. 6269 - 6272 (2007/10/02)
In applying N-methoxy-N-methylamides as acylating agents for carbanions, an unusual mode of reactivity was discovered.In particular, competitive transfer of a hydroxymethyl group was observed.The mechanism of this reaction is described, and involves a base induced E2 elimination of the N-methoxy-N-methylamide generating formaldehyde and the corresponding N-methylamide anion.
