3886-37-1Relevant academic research and scientific papers
Highly efficient preparation of amides from aminium carboxylates using N-(p-toluenesulfonyl) imidazole
Behrouz, Somayeh,Rad, Mohammad Navid Soltani,Forouhari, Elham
, p. 101 - 106 (2016/03/08)
Treatment of aminium carboxylates with N-(p-toluenesulfonyl)imidazole in the presence of triethylamine in DMF at 100 °C afforded the corresponding amides in good to excellent yields. N-(p-Toluenesulfonyl)imidazole proved to be a highly efficient coupling reagent for the preparation of numerous structurally diverse primary, secondary and tertiary amides.
Amides in one pot from Carboxylic Acids and Amines via Sulfinylamides
Bai, Jianfei,Zambron, Bartosz K.,Vogel, Pierre
supporting information, p. 604 - 607 (2014/04/03)
An efficient method has been developed for the direct amidification of carboxylic acids via sulfinylamides preformed in situ by the reaction of pure amines with prop-2- ene-1-sulfinyl chloride. The method can be applied to aliphatic acids, including pivalic acid, aromatic acids, and primary and secondary amines. It is compatible with acids bearing unprotected alcohol, phenol, and ketone moieties and applicable to the synthesis of peptides. It does not induce their a-epimerization.
Ethyl 2-cyano-2-(2-nitrobenzenesulfonyloxyimino)acetate (o -NosylOXY): A recyclable coupling reagent for racemization-free synthesis of peptide, amide, hydroxamate, and ester
Dev, Dharm,Palakurthy, Nani Babu,Thalluri, Kishore,Chandra, Jyoti,Mandal, Bhubaneswar
, p. 5420 - 5431 (2014/07/08)
Ubiquitousness of amide and ester functionality makes coupling reactions extremely important. Although numerous coupling reagents are available, methods of preparation of the common and efficient reagents are cumbersome. Those reagents generate a substantial amount of chemical waste and lack recyclability. Ethyl 2-cyano-2-(2-nitrobenzenesulfonyloxyimino)acetate (o-NosylOXY), the first member of a new generation of coupling reagents, produces byproducts that can be easily recovered and reused for the synthesis of the same reagent, making the method more environmentally friendly and cost-effective. The synthesis of amides, hydroxamates, peptides, and esters using this reagent is described. The synthesis of the difficult sequences, for example, the islet amyloid polypeptide (22-27) fragment (with a C-terminal Gly, H-Asn-Phe-Gly-Ala-Ile-Leu-Gly-NH 2) and acyl carrier protein (65-74) fragment (H-Val-Gln-Ala-Ala-Ile- Asp-Tyr-Ile-Asn-Gly-OH), following the solid-phase peptide synthesis (SPPS) protocol and Amyloid β (39-42) peptide (Boc-Val-Val-IIe-Ala-OMe), following solution-phase strategy is demonstrated. Remarkable improvement is noticed with respect to reaction time, yield, and retention of stereochemistry. A mechanistic investigation and recyclability are also described.
Ethyl 2-(tert-butoxycarbonyloxyimino)-2-cyanoacetate (Boc-Oxyma) as coupling reagent for racemization-free esterification, thioesterification, amidation and peptide synthesis
Thalluri, Kishore,Nadimpally, Krishna Chaitanya,Chakravarty, Maharishi Parasar,Paul, Ashim,Mandal, Bhubaneswar
supporting information, p. 448 - 462 (2013/05/09)
Here we report the synthesis and utility of ethyl 2-(tert- butoxycarbonyloxyimino)-2-cyanoacetate (Boc-Oxyma) as an efficient coupling reagent for racemization-free esterification, thioesterification, amidation reactions and peptide synthesis that uses equimolar amounts of acids and alcohols, thiols, amines or amino acids, respectively. Its application to solid phase as well as solution phase peptide synthesis is also demonstrated and a mechanistic investigation is discussed. Boc-Oxyma is similar to the well known coupling agent COMU {1-[1-cyano-2-ethoxy-2-oxoethylideneaminooxy)- dimethylaminomorpholino] uronium hexafluorophosphate} in terms of its high reactivity and mechanism of action. However, it is not only much easier to prepare, but also to recover and reuse, thereby generating far less chemical waste.
Catalyst and solvent-free amidation of inactive esters of N-protected amino acids
Nadimpally, Krishna Chaitanya,Thalluri, Kishore,Palakurthy, Nani Babu,Saha, Abhijit,Mandal, Bhubaneswar
supporting information; experimental part, p. 2579 - 2582 (2011/06/21)
A catalyst free procedure for the preparation of amides from inactive esters of N-protected amino acids and various amines is demonstrated under mild reaction conditions. Our effort to recover excess amine and generated alcohol is an approach towards environment friendly and cost effective synthesis under easy operational conditions.
Synthesis, physical-chemical characterisation and biological evaluation of novel 2-amido-3-hydroxypyridin-4(1H)-ones: Iron chelators with the potential for treating Alzheimer's disease
Gaeta, Alessandra,Molina-Holgado, Francisco,Kong, Xiao L.,Salvage, Sarah,Fakih, Sarah,Francis, Paul T.,Williams, Robert J.,Hider, Robert C.
experimental part, p. 1285 - 1297 (2011/03/23)
A novel class of 2-amido-3-hydroxypyridin-4-one iron chelators is described. These compounds have been designed to behave as suitable molecular probes which will improve our knowledge of the role of iron in neurodegenerative conditions. Neurodegenerative disorders, such as Alzheimer's disease (AD) and Parkinson disease (PD), can be considered as diverse pathological conditions sharing critical metabolic processes such as protein aggregation and oxidative stress. Interestingly, both these metabolic alterations seem to be associated with the involvement of metal ions, including iron. Iron chelation is therefore a potential therapeutic approach. The physico-chemical (pKa, pFe 3+ and log P) and biological properties (inhibition of iron-containing enzymes) of these chelators have been investigated in order to obtain a suitable profile for the treatment of neurodegenerative conditions. Studies with neuronal cell cultures confirm that the new iron chelators are neuroprotective against β-amyloid-induced toxicity.
Stereoselective palladium-catalyzed allylic alkylations of peptide amide enolates
Datta, Swarup,Kazmaier, Uli
supporting information; experimental part, p. 872 - 880 (2011/04/16)
Pd-catalyzed allylations are an excellent tool for stereoselective peptide modifications, being clearly superior to normal alkylations. The reactions proceed not only in high yield, but also high regio- and diastereoselectivities, and trans-products are f
IRON MODULATORS
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Page/Page column 15; Figure 3, (2010/11/24)
Iron modulator compounds of formula (I) are provided for treating amyloidoses wherein R1 is selected from H, C1-6 alkyl, C1-6 alkenyl, C1-6 hydroxyalkyl, C1-6 hydroxyalkenyl, R2 is selected from H, C1-6 alkyl, C1-6 alkenyl, C1-6 hydroxyalkyl, C1-6 hydroxyalkenyl and C6-10 aralykyl in which the aryl group of the aralkyl group is optionally substituted by hydroxy, halo or C1-4 alkyl R3 is selected from H, C1-6 alkyl, C1-6 alkenyl and C1-12 acyl; R4 is selected from H and C1-3 alkyl R5, R6 and R7 are independently selected from H, C1-6 alkyl, C3-7 aryl, and C1-10 aralkyl; the alkyl, aryl and aralkyl groups being optionally substituted by one or more halo, hydroxy and nitro groups or R5 and R7 together with the nitrogen atom to which they are bonded form a heterocyclic ring optionally substituted by one or more hydroxyl groups or a pharmaceutically acceptable tautomer, ester or addition salt thereof.
The direct conversion of carbamates to ureas using aluminum amides
Lee, Sang-Hyuep,Matsushita, Hana,Clapham, Bruce,Janda, Kim D.
, p. 3439 - 3443 (2007/10/03)
The conversion of carbamates into ureas using aluminum amide complexes is reported. This reaction is a convenient method to prepare bi-, tri- and tetra-substituted ureas from carbamate-protected primary or secondary amines by reaction with primary or secondary amines in the presence of stoichometric quantities of trimethylaluminum. A reactivity trend of the various carbamates was observed and methyl and benzyl carbamates were reacted selectively in the presence of t-butyl carbamates.
Enol esters as intermediates for the facile conversion of amino acids into amides and dipeptides
Kabouche,Bruneau,Dixneuf
, p. 5359 - 5362 (2007/10/02)
N-Protected amino enol esters are easily transformed at room temperature into amino amides, and in the presence of potassium cyanide as catalyst, into tertiary amides and dipeptides.
