27151-57-1Relevant academic research and scientific papers
Borane-Trimethylamine Complex as a Reducing Agent for Selective Methylation and Formylation of Amines with CO2
Zhang, Yanmeng,Zhang, He,Gao, Ke
supporting information, p. 8282 - 8286 (2021/10/25)
We report herein that a borane-trimethylamine complex worked as an efficient reducing agent for the selective methylation and formylation of amines with 1 atm CO2 under metal-free conditions. 6-Amino-2-picoline serves as a highly efficient catalyst for the methylation of various secondary amines, whereas in its absence, the formylation of primary and secondary amines was achieved in high yield with high chemoselectivity. Mechanistic studies suggest that the 6-amino-2-picoline-borane catalytic system operates like an intramolecular frustrated Lewis pair to activate CO2.
Visible-Light-Enabled Direct Decarboxylative N-Alkylation
Arman, Hadi D.,Dang, Hang T.,Haug, Graham C.,Larionov, Oleg V.,Nguyen, Viet D.,Nguyen, Vu T.,Vuong, Ngan T. H.
supporting information, p. 7921 - 7927 (2020/04/10)
The development of efficient and selective C?N bond-forming reactions from abundant feedstock chemicals remains a central theme in organic chemistry owing to the key roles of amines in synthesis, drug discovery, and materials science. Herein, we present a dual catalytic system for the N-alkylation of diverse aromatic carbocyclic and heterocyclic amines directly with carboxylic acids, by-passing their preactivation as redox-active esters. The reaction, which is enabled by visible-light-driven, acridine-catalyzed decarboxylation, provides access to N-alkylated secondary and tertiary anilines and N-heterocycles. Additional examples, including double alkylation, the installation of metabolically robust deuterated methyl groups, and tandem ring formation, further demonstrate the potential of the direct decarboxylative alkylation (DDA) reaction.
Diverse catalytic reactivity of a dearomatized PN3P?-nickel hydride pincer complex towards CO2 reduction
Li, Huaifeng,Gon?alves, Théo P.,Zhao, Qianyi,Gong, Dirong,Lai, Zhiping,Wang, Zhixiang,Zheng, Junrong,Huang, Kuo-Wei
supporting information, p. 11395 - 11398 (2018/10/20)
A dearomatized PN3P?-nickel hydride complex has been prepared using an oxidative addition process. The first nickel-catalyzed hydrosilylation of CO2 to methanol has been achieved, with unprecedented turnover numbers. Selective methylation and formylation of amines with CO2 were demonstrated by such a PN3P?-nickel hydride complex, highlighting its versatile functions in CO2 reduction.
Expanding the Ligand Framework Diversity of Carbodicarbenes and Direct Detection of Boron Activation in the Methylation of Amines with CO2
Chen, Wen-Ching,Shen, Jiun-Shian,Jurca, Titel,Peng, Chun-Jung,Lin, Yen-Hsu,Wang, Yi-Ping,Shih, Wei-Chih,Yap, Glenn P. A.,Ong, Tiow-Gan
supporting information, p. 15207 - 15212 (2016/01/25)
A simple and convergent synthetic strategy used to increase the diversity of the carbodicarbene ligand framework through incorporation of unsymmetrical pendant groups is reported. Structural analysis and spectroscopic studies of ligands and their Rh complexes are reported. Reactivity studies reveal carbodicarbenes as competent organocatalysts for amine methylation using CO2 as a synthon. A unique B-H-activated boron-carbodicarbene complex was isolated as a reaction intermediate, providing mechanistic insight into the CO2 functionalization process.
Direct Methylation of Amines with Carbon Dioxide and Molecular Hydrogen using Supported Gold Catalysts
Du, Xian-Long,Tang, Gao,Bao, Hong-Liang,Jiang, Zheng,Zhong, Xin-Hua,Su, Dang Sheng,Wang, Jian-Qiang
, p. 3489 - 3496 (2015/11/02)
The N-methylation of amines with CO2 and H2 is an important step in the synthesis of bioactive compounds and chemical intermediates. The first heterogeneous Au catalyst is reported for this methylation reaction with good to excellent yields. The average turnover frequency (TOF) based on surface Au atoms is 45 h-1, which is the highest TOF value ever reported for the methylation of aniline with CO2 and H2. Furthermore, the catalyst is tolerant toward a variety of amines, which includes aromatic, aliphatic, secondary, and primary amines. Preliminary mechanistic studies suggest that the N-alkyl formamide might be an intermediate in the N-methylation of amine process. Moreover, through a one-pot process, it is possible to convert primary amines, aldehydes, and CO2 into unsymmetrical tertiary amines with H2 as a reductant in the presence of the Au catalyst.
Metal-free catalyst for the chemoselective methylation of amines using carbon dioxide as a carbon source
Das, Shoubhik,Bobbink, Felix D.,Laurenczy, Gabor,Dyson, Paul J.
supporting information, p. 12876 - 12879 (2016/02/18)
N-methylation of amines is an important step in the synthesis of many pharmaceuticals and has been widely applied in the preparation of other key intermediates and chemicals. Therefore, the development of efficient methylation methods has attracted considerable attention. In this respect, carbon dioxide is an attractive C1 building block because it is an abundant, renewable, and nontoxic carbon source. Consequently, we developed a highly chemoselective, metal-free catalytic system that operates under ambient conditions for the N-methylation of amines. The methylation of amines with CO2 as C1 source and Ph2SiH2 as reducing agent was achieved with an N-heterocyclic carbene (NHC) as the catalyst. The catalyst is tolerant toward a variety of functional groups (including esters and ethers, nitro, nitrile, and carbonyl groups, and unsaturated C-C bonds); the reaction uses commercially available reagents and can be performed on a gram scale.
Promising core structure for nuclear receptor ligands: Design and synthesis of novel estrogen receptor ligands based on diphenylamine skeleton
Ohta, Kiminori,Chiba, Yuki,Ogawa, Takumi,Endo, Yasuyuki
scheme or table, p. 5050 - 5053 (2009/05/26)
Novel diphenylamine-type estrogen receptor ligands were designed and synthesized, and their biological activities were evaluated by means of binding assays for estrogen receptor-α and -β and cell proliferation assay using MCF-7 cells. Compounds 4f, 11b, 12c, and 8 showed moderate estrogenic activities. We propose that the diphenylamine skeleton may be a privileged structure for various nuclear receptor ligands, including RAR, RXR, and AR ligands.
A highly active catalyst for Pd-catalyzed amination reactions: Cross-coupling reactions using aryl mesylates and the highly selective monoarylation of primary amines using aryl chlorides
Fors, Brett P.,Watson, Donald A.,Biscoe, Mark R.,Buchwald, Stephen L.
supporting information; body text, p. 13552 - 13554 (2009/02/06)
A catalyst system based on a new biarylmonophosphine ligand (BrettPhos) that shows excellent reactivity for C-N cross-coupling reactions is reported. This catalyst system enables the use of aryl mesylates as a coupling partner in C-N bond-forming reactions. Additionally, the use of BrettPhos permits the highly selective monoarylation of an array of primary aliphatic amines and anilines at low catalyst loadings and with fast reaction times, including the first monoarylation of methylamine. Lastly, oxidative addition complexes of BrettPhos are included, which provide insight into the origin of reactivity for this system. Copyright
PURINE DERIVATIVES AS A2A RECEPTOR AGONISTS
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, (2008/06/13)
A compound of formula (I) or stereoisomers or pharmaceutically acceptable salts thereof.and their preparation and use as A2A receptor agonists
ORGANIC COMPOUNDS
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Page/Page column 47-48, (2008/06/13)
A compound of formula (I) or stereoisomers or pharmaceutically acceptable salts thereof, and their preparation and use as pharmaceuticals wherein Rl, R2 and R3 are as defined herein.
