2580-63-4Relevant articles and documents
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).
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%.
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
