2580-63-4Relevant academic research and scientific papers
Thioether-Directed NiH-Catalyzed Remote γ-C(sp3)-H Hydroamidation of Alkenes by 1,4,2-Dioxazol-5-ones
Chen, Qishu,Du, Bingnan,Ouyang, Yuxin,Yu, Wing-Yiu
supporting information, p. 14962 - 14968 (2021/09/29)
A NiH-catalyzed thioether-directed cyclometalation strategy is developed to enable remote methylene C-H bond amidation of unactivated alkenes. Due to the preference for five-membered nickelacycle formation, the chain-walking isomerization initiated by the NiH insertion to an alkene can be terminated at the γ-methylene site remote from the alkene moiety. By employing 2,9-dibutyl-1,10-phenanthroline as the ligand and dioxazolones as the reagent, the amidation occurs at the γ-C(sp3)-H bonds to afford the amide products in up to 90% yield (>40 examples) with remarkable regioselectivity (up to 24:1 rr).
Photoorganocatalytic One-Pot Synthesis of Hydroxamic Acids from Aldehydes
Papadopoulos, Giorgos N.,Kokotos, Christoforos G.
, p. 6964 - 6967 (2016/05/11)
An efficient one-pot synthesis of hydroxamic acids from aldehydes and hydroxylamine is described. A fast, visible-light-mediated metal-free hydroacylation of dialkyl azodicarboxylates was used to develop the subsequent addition of hydroxylamine hydrochloride. A range of aliphatic and aromatic aldehydes were employed in this reaction to give hydroxamic acids in high to excellent yields. Application of the current methodology was demonstrated in the synthesis of the anticancer medicine vorinostat.
Production of hydroxamic acids by immobilized Pseudomonas aeruginosa cells: Kinetic analysis in reverse micelles
Bernardo, Marisa,Pacheco, Rita,Serralheiro, Maria Luisa M.,Karmali, Amin
, p. 28 - 33 (2013/07/19)
Intact cells from Pseudomonas aeruginosa strain L10 containing amidase were used as biocatalysts both free and immobilized in a reverse micellar system. The apparent kinetic constants for the transamidation reaction in hydroxamic acids synthesis, were determined using substrates such as aliphatic, amino acid and aromatic amides and esters, in both media. In reverse micelles, K m values decreased 2-7 fold relatively to the free biocatalyst using as substrates acetamide, acrylamide, propionamide and glycinamide ethyl ester. We have concluded that overall the affinity of the biocatalyst to each substrate increases when reactions are performed in the reversed micellar system as opposed to the buffer system. The immobilized biocatalyst in general, exhibits higher stability and faster rates of reactions at lower substrates concentration relatively to the free form, which is advantageous. Additionally, the immobilization revealed to be suitable for obtaining the highest yields of hydroxamic acids derivatives, in some cases higher than 80%.
An enthalpic basis of additivity in biphenyl hydroxamic acid ligands for stromelysin-1
Wilfong, Erin M.,Du, Yu,Toone, Eric J.
supporting information, p. 6521 - 6524 (2012/11/07)
Fragment based drug discovery remains a successful tool for pharmaceutical lead discovery. Although based upon the principle of thermodynamic additivity, the underlying thermodynamic basis is poorly understood. A thermodynamic additivity analysis was performed using stromelysin-1 and a series of biphenyl hydroxamate ligands identified through fragment additivity. Our studies suggest that, in this instance, additivity arises from enthalpic effects, while interaction entropies are unfavorable; this thermodynamic behavior is masked by proton transfer. Evaluation of the changes in constant pressure heat capacities during binding suggest that solvent exclusion from the binding site does not account for the dramatic affinity enhancements observed.
Synthesis and Reactions of α-Bromo-N-alkoxyimidates
Shatzmiller, Shimon,Bercovici, Sorin
, p. 997 - 1004 (2007/10/02)
The reaction of alkyl hydroxamates 2 with (C2H5)3O*BF4 in CH2Cl2 affords N-alkoxyimidates 3.The direct alkylation of hydroxamic acids 1 with 1,2-dibromoethane gives the 5,6-dihydro-1,4,2-dioxazine derivatives 4.The reactions of the acyclic imidates 3 as well as the cyclic N-alkoxyimidates 4 with N-bromosuccinimide in CCl4 produces the α-bromoimidates 5a-d and 6a-d.The α-bromine atom in the bromides 5b, d and 6a, b, d can be displaced by fluorine and azido substituents to yield the α-fluoro-N-alkoxyimidates 7b, d and 10a, b, d and the α-azido compounds 8b, d and 11a, b, d, respectively.The reduction of the azides 8b, d and 11a, b, d affords the α-aminoimidates 9b, d and 12a, b, d, respectively.The reaction of the bromides 6a-d with benzene derivatives 14a-d in the presence of AgBF4 affords the aromatic substitution products 15a-d.Acid-catalyzed hydrolysis of 15a, c gives the arylsubstituted carboxylic acids 16 and 17. Key Words: Imidates, α-bromo- / 1,4,2-Dioxazines
cis-trans Isomerism in Monoalkylhydroxamic Acids by 1H, 13C and 15N NMR spectroscopy
Brown, David A.,Glass, William K.,Mageswaran, Rajeswary,Girmay, Berhane
, p. 970 - 973 (2007/10/02)
The first example of cis-trans isomerism in monoalkylhydroxamic acids, detected by 1H, 13C and 15N NMR spectroscopy, is reported.The 15N NMR spectrum of CH3CO(15)NHOH gave a clear assignment of the OH and NH protons of both Z and E isomers.The assignment was confirmed by 1H and 13C NMR spectroscopy.A rotational barrier of isomerization (ΔG++c) of 17.8 kcal mol -1 was calculated from the variable-temperature 1H NMR spectra using the method of Shanan-Atidi and Bar-Eli.KEY WORDS cis-trans Isomerism 1H, 13C and 15N NMR Monoalkylhydroxamic acids Rotational barrier
A FACILE PREPARATION OF ALIPHATIC HYDROXAMIC ACID FROM N,N,O-TRIS(TRIMETHYLSILYL)HYDROXYLAMINE AND ACID CHLORIDE
Ando, Wataru,Tsumaki, Hidetoshi
, p. 1053 - 1056 (2007/10/02)
N,N,O-Tris(trimethylsilyl)hydroxylamine reacts readily with various aliphatic acid chlorides under mild conditions to afford the corresponding hydroxamic acids in good yields.
