95725-08-9Relevant academic research and scientific papers
Room temperature copper-catalyzed oxidative amidation of terminal alkynes for the synthesis of α-ketoamides using: O -benzoyl hydroxylamines as aminating reagent and oxidant
Shen, Guodong,Zhao, Lingyu,Wang, Yichen,Zhang, Tongxin
, p. 78307 - 78310 (2016)
A novel and convenient copper-catalyzed oxidative amidation for the synthesis of α-ketoamides has been successfully developed, which uses easily available O-benzoyl hydroxylamines as aminating reagent and oxidant. The reaction proceeds smoothly at room temperature and is compatible with a range of substrates to give the desired products in moderate to good yields.
C-H/C-C Functionalization Approach to N-Fused Heterocycles from Saturated Azacycles
Ham, Jin Su,Park, Bohyun,Son, Mina,Roque, Jose B.,Jurczyk, Justin,Yeung, Charles S.,Baik, Mu-Hyun,Sarpong, Richmond
supporting information, p. 13041 - 13050 (2020/09/01)
Herein we report the synthesis of substituted indolizidines and related N-fused bicycles from simple saturated cyclic amines through sequential C-H and C-C bond functionalizations. Inspired by the Norrish-Yang Type II reaction, C-H functionalization of azacycles is achieved by forming α-hydroxy-β-lactams from precursor α-ketoamide derivatives under mild, visible light conditions. Selective cleavage of the distal C(sp2)-C(sp3) bond in α-hydroxy-β-lactams using a Rh-complex leads to α-acyl intermediates which undergo sequential Rh-catalyzed decarbonylation, 1,4-addition to an electrophile, and aldol cyclization, to afford N-fused bicycles including indolizidines. Computational studies provide mechanistic insight into the observed positional selectivity of C-C cleavage, which depends strongly on the groups bound to Rh trans to the phosphine ligand.
Aerobic oxidative amidation of alkynes using titanium oxide encapsulated cuprous iodide nanoparticles (CuI@TiO2)
Dutta, Pratip Kumar,Dhar, Basabbijayi,Sen, Subhabrata
, p. 12062 - 12071 (2018/07/24)
A catalyst consisting of titanium oxide encapsulated cuprous iodide nanoparticles was prepared via a sol-gel method using inexpensive raw materials and was harnessed successfully in the oxidative amidation of alkynes via an environmentally benign and sustainable protocol. The mechanism of action of this transformation was thoroughly discussed. The robustness of the catalyst was elucidated by the synthesis of diverse analogues of α-ketoarylamide from a variety of electron rich and poor substrates via a simple procedure in moderate to high yields, with no generation of toxic by-products, in good recyclability up to five cycles, under solvent free and aerobic conditions. The chemical nature, morphology and loading of the CuI@TiO2 nanocatalyst were investigated by TEM, SEM, XPS, EDX, powder XRD, BET, TGA and ICP-MS.
Palladium-Catalysed Double Carbonylation of Aryl Halides To Give α-Keto Amides. Mechanistic Studies
Ozawa, Fumiyuki,Soyama, Hidehiko,Yanagihara, Hisayoshi,Aoyama, Issei,Takino, Hiroaki,et al.
, p. 3235 - 3245 (2007/10/02)
Various aryl halides are catalytically converted into α-keto amides and amides on treatment with secondary amines and carbon monoxide.Palladium complexes containing tertiary phosphine ligands, particularly diphenylmethylphosphine and 1,4-bis(diphenylphosphino)butane, are most effective among other transition-metal complexes.Detailed examination of factors controlling the reaction rates and selectivity for α-keto amide formation revealed the following characteristics of the reactions. (a) Reactivity of phenyl halide decreases in the order PhI > PhBr >> PhCl. (b) Oxidative addition of phenyl bromide constitutes the rate-determining step in double carbonylation of phenyl bromide, whereas in the reaction of phenyl iodide the rate determinig step is associated with the reaction of a catalitically active palladium species with carbon monoxide. (c) Introduction of an electron-withdrawing substituent into the para position of phenyl halide enhances the reactivity but decreases the selectivity for α-keto amide. (d) Employment of amines of high basicity (pKb Et2NH > piperidine > hexamethyleneimine > Me2NH > pyrrolidine probably reflects the decrease in steric bulkiness of amines. (f) Although primary amines are in general not suitable for the double carbonylation, tert-butylamine can be used because of its inertness to the product α-keto amide.Reactivity of trans-PdPh(I)(PMePh2)2 and trans-Pd(COPh)I(PMePh2)2, supposed intermediates in the catalytic reaction of PhI, toward amines and CO was examined.The relative reactivity of six secondary amines with the benzoylpalladium complex increasing in the order Pr2NH Et2NH piperidine Me2NH hexamethyleneimine pyrrolidine was found to be inversely correlated with decreasing selectivity order for α-keto amide formation in the catalytic systems.On the basis of the experimental results, a mechanism consisting of two catalytic cycles to produce α-keto amides and amides has been proposed.
