1077-18-5Relevant academic research and scientific papers
Organic reactions catalyzed by methylrhenium trioxide: Reactions of ethyl diazoacetate and organic azides
Zhu, Zuolin,Espenson, James H.
, p. 9901 - 9907 (1996)
Methylrhenium trioxide (CH3ReO3 or MTO) catalyzes several classes of reactions of ethyl diazoacetate, EDA. It is the first high valent oxo complex for carbene transfer. Under mild conditions and in the absence of other substrates, EDA was converted to a 9:1 mixture of diethyl maleate and diethyl fumarate. In the presence of alcohols, α-alkoxy ethyl acetates were obtained in good yield. The yields dropped for the larger and more branched alcohols, the balance of material being diethyl maleate and fumarate. An electron-donating group in the para position of phenols favors the formation of α-phenoxy ethyl acetates. The use of EDA to form α-thio ethyl acetates and N-substituted glycine ethyl esters, on the other hand, is hardly affected by the size or structure of the parent thiol or amine, with all of these reactions proceeding in high yield. MTO-catalyzed cycloaddition reactions occur between EDA and aromatic imines, olefins, and carbonyl compounds. Three-membered ring products are formed: aziridines, cyclopropanes, and epoxides, respectively. The reactions favor the formation of trans products, and provide a convenient route for the preparation of aziridines. Intermediate carbenoid and nitrenoid species have been proposed. In the presence of an oxygen source such as an epoxide, ethyl diazoacetate and azibenzil are converted to an oxalic acid monoethyl ester and tobenzil; at the same time the epoxide was converted to an olefin. These results provide further support for the proposed intermediate, a cyclic species containing Re, O, and CHCO2Et (or, occasionally, CPhC(O)Ph)in a three-membered ring.
An in-depth analysis of the effect of substituents on imines in cycloaddition reactions with nitrosoalkenes
Marwaha, Alka,Singh, Parvesh,Mahajan, Mohinder P.
, p. 5474 - 5486 (2006)
An in-depth experimental and theoretical analysis of the reactions of simple acyclic imines with nitrosoalkenes is reported. The effect of the substituents on nitrogen as well as carbon atom of imines on the cycloaddition pathways followed is systematically explored. The reactions of various functionalized imines with nitrosoalkenes leading to the formation of imidazoles and imidazole-N-oxides have also been explored. The plausible mechanisms leading to various heterocycles have been proposed.
Crystal phase effect of iron oxides on the aerobic oxidative coupling of alcohols and amines under mild conditions: A combined experimental and theoretical study
Geng, Longlong,Jian, Wei,Jing, Pei,Zhang, Wenxiang,Yan,Bai, Fu-Quan,Liu, Gang
, p. 145 - 152 (2019)
Selective catalytic oxidation using air as the terminal oxidant is an ecofriendly route for the synthesis of fine and commodity chemicals. However, the catalyst generally faces the challenges of the inertness of molecular oxygen, limited substrate scope, poor selectivity, and high cost. Moreover, the toxicity of the catalyst should also be considered when the products are used in pharmaceutical or biotechnological areas. Here, upon investigating the dependence of catalytic oxidation on the crystal phases of iron oxides, we find that naked γ-Fe2O3 particles exhibit excellent catalytic activity, selectivity, and stability in a series of imine synthetic reactions. The performance of γ-Fe2O3 particles is significantly better than that of α-Fe2O3 and Fe3O4 under mild reaction conditions, and the γ-Fe2O3 catalyst can be separated from the reaction mixture magnetically. Both experimental and theoretical calculation results show that γ-Fe2O3 possesses supercapability for oxygen activation. The inverse spinel structure of γ-Fe2O3 has abundant cation vacancies, which confers unique electronic properties on surface Fe species. These Fe species tend to transfer electrons to molecular oxygen to form O2? or O22? species. These oxygen species are favorable for the dehydrogenation of alcohols, which is responsible for the high activity of γ-Fe2O3 in this coupling reaction.
Synthesis of [LAl(μ-S)2AlL] (L?=?HC(CMeNAr)2, Ar?=?2,6-Et2C6H3) with the insertion of sulfur into the Al–H bonds of LAlH2 and its application in catalysis
Zhong, Mingdong,Liu, Ying,Liu, Xin,Ma, Xiaoli,Yang, Zhi
, p. 182 - 185 (2017)
Two aluminum complexes [LAl(μ-S)2AlL] (1) and [LAl(SeH)2] (2) were synthesized in good yield by reacting one equivalent of LAlH2 (L?=?HC(CMeNAr)2, Ar?=?2,6-Et2C6H3) with one equivalent of S and with two equivalents of Se without any catalysts, respectively. Complexes 1 and 2 have been characterized by 1H and 13C NMR, elemental analyses, and single crystal X-ray structural analysis. Furthermore, the good catalytic activity of 1 as bimetallic Lewis acid catalyst for the addition reaction of TMSCN to aldehydes and aldimine condensation reactions, respectively, were investigated.
Silica functionalized Cu(II) acetylacetonate Schiff base complex: An efficient catalyst for the oxidative condensation reaction of benzyl alcohol with amines
Anbarasu,Malathy,Karthikeyan,Rajavel
, p. 305 - 312 (2017)
Silica functionalized Cu(II) acetylacetonate Schiff base complex via the one pot reaction of silica functionalized 3-aminopropyltriethoxysilane with acetyl acetone and copper acetate has been reported. The synthesized material was well characterized by analytical techniques such as FT-IR, UV-DRS, XRD, SEM-EDX, HR-TEM, EPR, ICP-AES and BET analysis. The characterization results confirmed the grafting of Cu(II) Schiff base complex on the silica surface. The catalytic activity of synthesized silica functionalized Cu(II) acetylacetonate Schiff base complex was evaluated through the oxidative condensation reaction of benzyl alcohol to imine.
Synthesis of organoaluminum chalcogenides and their applications in Lewis acid catalysis
Ding, Yi,Ma, Xiaoli,Liu, Yashuai,Liu, Wenqing,Ni, Congjian,Yan, Ben,Yan, Li,Yang, Zhi
, (2019)
Two chalcogenide bridged bi-aluminum compounds [LAl(NMe3)(μ-S)Al(NMe3)L] (1) and [LAl(NMe3)(μ-Se)Al(NMe3)L] (2) were synthesized by reacting LAlH(NMe3) (L = 4-methylbenzylidene-o-aminothiophenol) with
Direct and mild palladium-catalyzed aerobic oxidative synthesis of imines from alcohols and amines under ambient conditions
Jiang, Lan,Jin, Luolu,Tian, Haiwen,Yuan, Xueqin,Yu, Xiaochun,Xu, Qing
, p. 10833 - 10835 (2011)
By ligand, TEMPO, and base screening, we developed a mild and green one-pot imine synthesis from alcohols and amines via a low-loading palladium-catalyzed tandem aerobic alcohol oxidation-dehydrative condensation reaction that can be readily carried out in open air at room temperature.
A visible-light-responsive metal-organic framework for highly efficient and selective photocatalytic oxidation of amines and reduction of nitroaromatics
Chen, Peiqi,Guo, Zhifen,Liu, Xin,Lv, Hui,Che, Yan,Bai, Rong,Chi, Yanhong,Xing, Hongzhu
, p. 27074 - 27080 (2019)
Photocatalysis is a green synthetic method for organics transformation. We present here the synthesis of a novel visible-light-responsive metal-organic framework and its photocatalytic application. The prepared MOF is highly efficient for the self-coupling of primary amines and oxidative dehydrogenation of secondary amines to selectively produce imines assisted by the green and economic oxidant of molecular oxygen. Studies reveal that both energy transfer and electron transfer from the photoexcited MOF to molecular oxygen are important for amine oxidation, where the highly reactive species of superoxide radicals and singlet oxygen together account for the high catalytic performance. The photogenerated electrons of the MOF have also been utilized for the reduction of aromatic nitroarenes. Results show that they are highly selective for the reduction of nitroarenes to produce anilines in the presence of hydrazine hydrate. The work demonstrates the enormous potential of photoactive MOFs for converting organic substrates into valuable chemicals.
KOH-mediated transition metal-free synthesis of imines from alcohols and amines
Xu, Jian,Zhuang, Rongqiang,Bao, Lingling,Tang, Guo,Zhao, Yufen
, p. 2384 - 2387 (2012)
The various imines were prepared from alcohols and amines in moderate to good yields under an air atmosphere promoted by KOH, eliminating the need for toxic transition metal catalysts. Due to its simplicity, this protocol will have wide application in synthesis.
Reaction of Thioaldehydes with Amines
Okuma, Kentaro,Komiya, Yasuo,Ohta, Hiroshi
, p. 2402 - 2406 (1991)
The reaction of phosphonium ylides with elemental sulfur gave thioaldehydes, which changed to the corresponding thioamides in good yields when treated with amines.When thioaldehydes containing α-hydrogens were treated with secondary amines, the corresponding enamines or reduction products were obtained.
