5625-90-1Relevant articles and documents
N-Heterocyclic Carbene-Stabilized Germa-acylium Ion: Reactivity and Utility in Catalytic CO2Functionalizations
Sarkar, Debotra,Weetman, Catherine,Dutta, Sayan,Schubert, Emeric,Jandl, Christian,Koley, Debasis,Inoue, Shigeyoshi
supporting information, p. 15403 - 15411 (2020/10/20)
The first acceptor-free heavier germanium analogue of an acylium ion, [RGe(O)(NHC)2]X (R = MesTer = 2,6-(2,4,6-Me3C6H2)2C6H3; NHC = IMe4 = 1,3,4,5-tetramethylimidazol-2-ylidene; X = (Cl or BArF = {(3,5-(CF3)2C6H5)4B}), was isolated by reacting [RGe(NHC)2]X with N2O. Conversion of the germa-acylium ion to the first solely donor-stabilized germanium ester [(NHC)RGe(O)(OSiPh3)] and corresponding heavier analogues ([RGe(S)(NHC)2]X and [RGe(Se)(NHC)2]X) demonstrated its classical acylium-like behavior. The polarized terminal GeO bond in the germa-acylium ion was utilized to activate CO2 and silane, with the former found to be an example of reversible activation of CO2, thus mimicking the behavior of transition metal oxides. Furthermore, its transition-metal-like nature is demonstrated as it was found to be an active catalyst in both CO2 hydrosilylation and reductive N-functionalization of amines using CO2 as the C1 source. Mechanistic studies were undertaken both experimentally and computationally, which revealed that the reaction proceeds via an N-heterocyclic carbene (NHC) siloxygermylene [(NHC)RGe(OSiHPh2)].
In situ generated amine as a Lewis base catalyst in the reaction of 3,7-dinitro-1,3,5,7-tetraazabicyclo[3.3.1]nonane in nitric acid: Experimental and DFT study
Zhang, Yu,Chi, Guoli,He, Ying,Xu, Zishuai,Zhang, Luyao,Luo, Jun,Zhou, Baojing
supporting information, (2019/04/08)
The problem how ammonium nitrate affects the nitrolysis of 3,7-dinitro-1,3,5,7-tetraazabicyclo[3.3.1]nonane (DPT) in nitric acid to prepare 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) has puzzled chemists for decades. In this paper, experimental work and theoretical calculation are described to investigate the long-standing challenge. The experiment results showed that ammonium nitrate or alkylammonium chlorides were in favor of the formation of 1-nitroso-3,5,7-trinitro-1,3,5,7-tetraazacyclooctane (MNX) but hindered the conversion of MNX to HMX. A plausible catalytic mechanism was proposed. In which ammonia or amines, in situ generated from the unfavorable balance with their salts, act as Lewis base catalysts. At the same time, the DFT computation results reveal that rigid bicyclic transition states established with 1-hydroxymethyl-3,5,7-trinitro-1,3,5,7-tetraazacyclooctane, ammonia (or amines) and three water molecules lead to very low activation energies. Then, a novel process for the preparation of MNX with excellent yield up to 78.5% was developed, which is free of the use of NaNO2 or N2O4 as nitroso resources.
Supported nano-gold-catalyzed N-formylation of amines with paraformaldehyde in water under ambient conditions
Ke, Zhengang,Zhang, Yan,Cui, Xinjiang,Shi, Feng
, p. 808 - 816 (2016/02/12)
A simple and efficient Au/Al2O3 catalyst was prepared by the co-precipitation method for the oxidative N-formylation of amines with paraformaldehyde. Under the optimized reaction conditions, excellent amine conversion and N-formamide selectivity can be obtained with up to 97% yield with water as the solvent under ambient conditions. This catalyst tolerated a wide range of primary amines and second amines, and it can be reused for at least five runs without obvious deactivation.
Method for preparing kakonein derivatives
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Paragraph 0037-0039, (2017/03/17)
The invention discloses a puerarin derivative preparation method. Puerarin derivative has the structural formula as shown in the specification, and the puerarin derivative is obtained by that puerarin reacts with CH2(R)2, wherein R is a tertiary amine gene. The puerarin derivative preparation method is characterized in that reaction is carried out under hydrochloric acid catalysis. Compared with the prior art, the puerarin derivative preparation method is characterized in that the yield of a puerarin derivative product can be obviously improved after the class of reaction adopts hydrochloric acid catalysis.
(E)-α,β-unsaturated amides from tertiary amines, olefins and CO via Pd/Cu-catalyzed aerobic oxidative N-dealkylation
Shi, Renyi,Zhang, Hua,Lu, Lijun,Gan, Pei,Sha, Yuchen,Zhang, Heng,Liu, Qiang,Beller, Matthias,Lei, Aiwen
supporting information, p. 3247 - 3250 (2015/06/16)
A novel Pd/Cu-catalyzed chemoselective aerobic oxidative N-dealkylation/carbonylation reaction has been developed. Tertiary amines are utilized as a "reservoir" of "active" secondary amines in this transformation, which inhibits the formation of undesired by-products and the deactivation of the catalysts. This protocol allows for an efficient and straightforward construction of synthetically useful and bioactive (E)-α,β-unsaturated amide derivatives from easily available tertiary amines, olefins and CO. This journal is
Nonstabilised azomethine ylids from n-oxides: Unravelling the deprotonation of n-methylmorpholine n-oxide
Mirzayans, Paul Malek,Krenske, Elizabeth H.,Williams, Craig M.
, p. 1309 - 1317 (2014/11/07)
Nonstabilised azomethine ylids (NAYs) are useful 1,3-dipoles, but their synthetic applications are restricted by the high temperatures often needed for their generation, and by an incomplete understanding of the effect of heteroatoms in cyclic systems. We have examined the behaviour of N-methylmorpholine N-oxide (NMO) as a NAY precursor in the Roussi reaction (low-temperature reaction of an N-oxide with strong base). The choice of base is critical to achieving cycloadduct formation. We report synthetic and computational (density functional theory) investigations of the products obtained with different bases and their mechanisms of formation.
Synthesis and aminomethylation of 7-hydroxy-5-methoxyisoflavones
Mrug,Bondarenko,Khilya,Frasinyuk
, p. 235 - 241 (2013/07/26)
A synthetic method for 7-hydroxy-5-methoxyisoflavones starting from 5,7-dihydroxyisoflavones was developed. Dimethylcarbamoylchloride was proposed for protection of the 7-hydroxy group. Aminomethylation of the synthesized 7-hydroxy-5-methoxyisoflavones by formaldehyde aminals was studied.
Cooperative catalysis with aldehydes and copper: Development and application in aerobic oxidative C-H amination at room temperature
Xie, Yinjun,Qian, Bo,Xie, Pan,Huang, Hanmin
supporting information, p. 1315 - 1322 (2013/06/27)
A conceptually new cooperative catalytic system via a synergistic combination of aldehyde and copper catalysis has been established based on systemic mechanistic studies. This new cooperative catalysis has been successfully applied in the direct aerobic oxidative C-H amination of azoles at room temperature, which was previously realized under harsh conditions. Mechanistic studies including isotopic labeling experiments and kinetic isotope effect (KIE) experiments support a reaction pathway that involves formation of an aminal, hydrolysis of the aminal to generate the copper-amide species, subsequent C-H amination and re-oxidation of copper(I) to copper(II) by oxygen. It not only provides an efficient method to realize the oxidative C-H amination of benzoxazoles with free amines at room temperature, but also paves the way for establishing new C-N bond formation reactions by using this efficient cooperative catalysis. Copyright
Copper-catalyzed aerobic oxidative amination of arylboronic acid with aminal under base-free conditions
Zhou, Yanping,Xie, Yinjun,Yang, Lei,Xie, Pan,Huang, Hanmin
supporting information, p. 2713 - 2716 (2013/06/05)
A new process involving copper-catalyzed oxidative amination reaction of various arylboronic acids with aminals under mild conditions has been developed. The key copper-amide species involved in the C-N bond-forming process was generated via C-N bond cleavage of aminal under base-free conditions. Moderate yields of desired amination products can be obtained under mild conditions when air was served as oxidant and PhCO2H was used as an additive.
Synthesis of amino sulfides in the presence of rare-earth and transition metal catalysts
Khairullina, R. R.,Akmanov, B. F.,Kunakova, R. V.,Ibragimov, A. G.
, p. 902 - 907,6 (2020/08/31)
Efficient procedures have been developed for the synthesis of amino sulfides by aminomethylation of thiols with higher geminal diamines, thiomethylation of secondary amines with N,N-dimethylaminomethyl sulfides, and decyclization of 1,3,6-oxadithiepane or
