874394-02-2Relevant academic research and scientific papers
Cobalt-Catalyzed Intermolecular C-H Amidation of Unactivated Alkanes
Lee, Jeonghyo,Jin, Seongho,Kim, Dongwook,Hong, Soon Hyeok,Chang, Sukbok
, p. 5191 - 5200 (2021)
Alkanes are an abundant and inexpensive source of hydrocarbons; thus, development of new methods to convert the hydrocarbon feedstocks to value-added chemicals is of high interest. However, it is challenging to achieve such transformation in a direct and selective manner mainly due to the intrinsic inertness of their C-H bonds. We herein report a tailored Cp*Co(III)(LX)-catalyzed efficient and site-selective intermolecular amidation of unactivated hydrocarbons including light alkanes. Electronic modulation of the cobalt complexes led to the enhanced amidation efficiency, and these effects were theoretically rationalized by the FMO analysis of presupposed cobalt nitrenoid species. Under the current cobalt protocol, a secondary C-H bond selectivity was observed in various nonactivated alkanes to reverse the intrinsic tertiary preference, which is attributed to the steric demands of the cobalt system that imposes difficulties in accessing tertiary C-H bonds. Experimental and computational studies suggested that the putative triplet Co nitrenoids are transferred to the C-H bonds of alkanes via a radical-like hydrogen abstraction pathway.
Nickel/Photoredox Dual Catalytic Cross-Coupling of Alkyl and Amidyl Radicals to Construct C(sp3)-N Bonds
Zhou, Shaofang,Lv, Kang,Fu, Rui,Zhu, Changlei,Bao, Xiaoguang
, p. 5026 - 5034 (2021/05/07)
The construction of C(sp3)-N bonds via direct radical-radical cross-coupling under benign conditions is a desirable but challenging approach. Herein, the cross-coupling of alkyl and amidyl radicals to build aliphatic C-N bonds in a concise, mild, and oxid
Catalytic Decarboxylative C?N Formation to Generate Alkyl, Alkenyl, and Aryl Amines
Zhang, Yipin,Ge, Xia,Lu, Hongjian,Li, Guigen
supporting information, p. 1845 - 1852 (2020/12/01)
Transition-metal-catalyzed sp2 C?N bond formation is a reliable method for the synthesis of aryl amines. Catalytic sp3 C?N formation reactions have been reported occasionally, and methods that can realize both sp2 and sp3 C?N formation are relatively unexplored. Herein, we address this challenge with a method of catalytic decarboxylative C?N formation that proceeds through a cascade carboxylic acid activation, acyl azide formation, Curtius rearrangement and nucleophilic addition reaction. The reaction uses naturally abundant organic carboxylic acids as carbon sources, readily prepared azidoformates as the nitrogen sources, and 4-dimethylaminopyridine (DMAP) and Cu(OAc)2 as catalysts with as low as 0.1 mol % loading, providing protected alkyl, alkenyl and aryl amines in high yields with gaseous N2 and CO2 as the only byproducts. Examples are demonstrated of the late-stage functionalization of natural products and drug molecules, stereospecific synthesis of useful α-chiral alkyl amines, and rapid construction of different ureas and primary amines.
Multi-functional aromatic amine compound as well as preparation method and application thereof
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Paragraph 0176-0182, (2021/08/14)
The invention belongs to the technical field of synthesis of aromatic amine compounds, and particularly relates to a multi-functional aromatic amine compound as well as a preparation method and application thereof. The invention provides a multi-functional aromatic amine compound and also provides a preparation method of the multi-functional aromatic amine compound. The amination reaction of aromatic carboxylic acid is catalyzed by DMAP at a relatively low temperature under the condition of no transition metal, and the method can be used for synthesizing a series of multi-functional aromatic amine compounds. The preparation method has not been reported in literature at present. The invention also provides a derivative product of arylamine and a preparation method thereof, and an application of the multi-functional aromatic amine compound in later modification of active molecules. The compound can be used for construction of optical active urea compounds and some important active molecules, and has a development prospect in synthesis of active drugs and natural products.
[RuIV(F20-TPP)Cl2]efficiently catalysed inter- and intra-molecular nitrene insertion into sp3 C-H bonds of hydrocarbons using phosphoryl azides as nitrene sources
Xiao, Wenbo,Wei, Jinhu,Zhou, Cong-Ying,Che, Chi-Ming
supporting information, p. 4619 - 4621 (2013/06/04)
[RuIV(F20-TPP)Cl2][H2(F 20-TPP) = meso-tetrakis(pentafluorophenyl)porphyrin] is an active catalyst for both inter- and intra-molecular nitrene insertion into sp 3 C-H bonds of hydrocarbons in good to high product yields using phosphoryl azides as nitrene sources. The Royal Society of Chemistry 2013.
N-tosyloxycarbamates as reagents in rhodium-catalyzed C-H amination reactions
Huard, Kim,Lebel, Helene
scheme or table, p. 6222 - 6230 (2009/05/27)
Metal nitrenes for use in C-H insertion reactions were obtained from N-tosyloxycarbamates in the presence of an inorganic base and a rhodium(II) dimer complex catalyst. The C-H amination reaction proceeds smoothly, and the potassium tosylate that forms as a byproduct is easily removed by filtration or an aqueous workup. This new methodology allows the amination of ethereal, benzylic, tertiary, secondary, and even primary C-H bonds. The intramolecular reaction provides an interesting route to various substituted oxazolidinones, whereas the intermolecular reaction gives trichloroethoxycarbonyl-protected amines that can be isolated with moderate to excellent yields and that cleave easily to produce the corresponding free amine. The development, scope, and limitations of the reactions are discussed herein. Isotopic effects and the electronic nature of the transition state are used to discuss the mechanism of the reaction.
De novo synthesis of troc-protected amines: Intermolecular rhodium-catalyzed C-H amination with N-tosyloxycarbamates
Lebel, Helene,Kim, Huard
, p. 639 - 642 (2008/02/03)
The rhodium-catalyzed intermolecular C-H insertion of the nitrene derived from 2,2,2-trichloroethyl-N-tosyloxycarbamate proceeded in good to excellent yields to produce a variety of Troc-protected amines. With cyclic aliphatic alkanes, it is possible to use only 2 equiv of substrate, whereas the reaction with aromatic alkanes is run neat. Not only does the nitrene insertion proceed in benzylic, secondary, and tertiary C-H bonds but also primary C-H insertion products were obtained in good yields. Finally, the use of chiral rhodium catalysts to provide an enantioselective version of this process is discussed.
A new practical method for the synthesis of unsymmetrical ureas via high-pressure-promoted condensation of 2,2,2-trichloroethyl carbamates (Troc-carbamates) with amines
Azad, Saleha,Kumamoto, Koji,Uegaki, Kaoru,Ichikawa, Yoshiyasu,Kotsuki, Hiyoshizo
, p. 587 - 590 (2007/10/03)
A new practical method for the synthesis of unsymmetrical ureas was achieved by condensation between 2,2,2-trichloroethyl carbamates (Troc-carbamates) and primary or secondary amines under high-pressure conditions.
