72538-32-0Relevant articles and documents
Kinetics and Mechanisms of Nucleophilic Displacements with Heterocycles as Leaving Groups. 3. N-(Substituted benzyl)-2,4,6-triphenylpyridiniums: Effects of Benzyl Substitution on First- and Second-Order Rates
Katritzky, Alan R.,Musumarra, Giuseppe,Sakizadeh, Kumars
, p. 3831 - 3835 (1981)
1-(p-Methoxybenzyl)- and 1-(2-furfuryl)-2,4,6-triphenylpyridiniums react with piperidine in chlorobenzene by SN1 and SN2 mechanisms, the proportion of SN1 increasing with temperature.Other 1-(substituted benzyl) derivative
Visible-Light-Induced Regioselective Deaminative Alkylation of Coumarins via Photoredox Catalysis
Tao, Maoling,Wang, An-Jun,Guo, Peng,Li, Weipiao,Zhao, Liang,Tong, Jie,Wang, Haoyang,Yu, Yanbo,He, Chun-Yang
supporting information, p. 24 - 29 (2021/10/19)
3-Alkylated coumarins have many applications in medicinal chemistry, however, methods access to such structures are still limited. Herein, we report a site-selective photocatalytic deaminative alkylation of coumarins utilizing pyridinium-activated aliphatic primary amines as alkylation reagents. The protocol was highlighted by its mild reaction conditions, operational simplicity, and broad functional group compatibility. Moreover, this strategy enables late-stage modification of some pharmaceuticals and natural products, thus providing an appealing approach to valuable molecules in medicinal chemistry. (Figure presented.).
C-H Alkylation of Aldehydes by Merging TBADT Hydrogen Atom Transfer with Nickel Catalysis
Murugesan, Vetrivelan,Ganguly, Anirban,Karthika, Ardra,Rasappan, Ramesh
, p. 5389 - 5393 (2021/07/21)
Catalyst controlled site-selective C-H functionalization is a challenging but powerful tool in organic synthesis. Polarity-matched and sterically controlled hydrogen atom transfer (HAT) provides an excellent opportunity for site-selective functionalization. As such, the dual Ni/photoredox system was successfully employed to generate acyl radicals from aldehydes via selective formyl C-H activation and subsequently cross-coupled to generate ketones, a ubiquitous structural motif present in the vast majority of natural and bioactive molecules. However, only a handful of examples that are constrained to the use of aryl halides are developed. Given the wide availability of amines, we developed a cross-coupling reaction via C-N bond cleavage using the economic nickel and TBADT catalyst for the first time. A range of alkyl and aryl aldehydes were cross-coupled with benzylic and allylic pyridinium salts to afford ketones with a broad spectrum of functional group tolerance. High regioselectivity toward formyl C-H bonds even in the presence of α-methylene carbonyl or α-amino/oxy methylene was obtained.
The Formal Cross-Coupling of Amines and Carboxylic Acids to Form sp3–sp3 Carbon–Carbon Bonds
Cernak, Tim,Zhang, Zirong
supporting information, p. 27293 - 27298 (2021/11/22)
We have developed a deaminative–decarboxylative protocol to form new carbon(sp3)–carbon(sp3) bonds from activated amines and carboxylic acids. Amines and carboxylic acids are ubiquitous building blocks, available in broad chemical diversity and at lower cost than typical C?C coupling partners. To leverage amines and acids for C?C coupling, we developed a reductive nickel-catalyzed cross-coupling utilizing building block activation as pyridinium salts and redox-active esters, respectively. Miniaturized high-throughput experimentation studies were critical to our reaction optimization, with subtle experimental changes such as order of reagent addition, composition of a binary solvent system, and ligand identity having a significant impact on reaction performance. The developed protocol is used in the late-stage diversification of pharmaceuticals while more than one thousand systematically captured and machine-readable reaction datapoints are reposited.
Photocatalytic deaminative benzylation and alkylation of tetrahydroisoquinolines with N-alkylpyrydinium salts
No?l, Timothy,Sambiagio, Carlo,Sch?nbauer, David,Schnürch, Michael
, p. 809 - 817 (2020/05/18)
A ruthenium-catalyzed photoredox coupling of substituted N-aryltetrahydroisoquinolines (THIQs) and different bench-stable pyridinium salts was successfully developed to give fast access to 1-benzyl-THIQs. Furthermore, secondary alkyl and allyl groups were also successfully introduced via the same method. Additionally, the typically applied N-phenyl group in the THIQ substrate could be replaced by the cleavable p-methoxyphenyl (PMP) group and successful N-deprotection was demonstrated.
Visible Light-Driven α-Alkylation of N-Aryl tetrahydroisoquinolines Initiated by Electron Donor-Acceptor Complexes
Dai, Peng,Deng, Hongping,Li, Yufei,Wang, Xinmin,Xia, Qing,Zhang, Wei-Hua
supporting information, p. 7290 - 7294 (2020/10/12)
The visible light-driven α-alkylation of N-aryl tetrahydroisoquinolines was initiated through electron donor-acceptor complex photochemistry. The reaction can proceed smoothly without the addition of any photocatalysts, transition-metal catalysts, or additional oxidants. The proposed mechanism was supported by various mechanistic studies, and the reactive open-shell alkyl radicals were generally produced from an alkylamine and underwent radical coupling for alkylating a wide range of N-aryl tetrahydroisoquinolines.
Method for difluoroalkylation after fatty amine deamination
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Page/Page column 0179; 0180; 0181, (2020/11/23)
The invention discloses a method for difluoroalkylation after fatty amine deamination in the field of organic synthesis. Particularly the method comprises the following steps: by taking simple and easily available fatty amine represented by a formula A as a raw material, reacting the fatty amine with pyranyl tetrafluoroborate represented by a formula B under a heating or room temperature conditionto obtain alkyl pyridinium represented by a formula C; and under the illumination condition, obtaining various difluoroalkyl substituted alkanes, cycloalkanes and derivatives thereof with high yieldby selecting commercially available [Ir(dtbbpy)(ppy)2]PF6 as a catalyst and difluoroenol silyl ether D as a difluoroalkylation reagent. According to the invention, the method is simple and convenientto operate, simple and mild in reaction condition, excellent in functional group compatibility and suitable for large-scale production and synthesis; and fluorine-containing amino acid with potentialapplication value can be obtained through the catalytic synthesis method, and various difluoroalkyl-containing compounds with novel structures and important significance in the fields of medicines, pesticides and materials can be easily obtained through further conversion of the obtained product.
Method of using calcilytic compounds
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, (2008/06/13)
The present invention features calcilytic compounds. "Calcilytic compounds" refer to compounds able to inhibit calcium receptor activity. Also described are the use of calcilytic compounds to inhibit calcium receptor activity and/or achieve a beneficial effect in a patient; and techniques which can be used to obtain additional calcilytic compounds.
The Synthesis and Reactions of Sterically Constrained Pyrylium and Pyridinium Salts
Katritzky, Alan R.,Thind, Sukhpal S.
, p. 1895 - 1900 (2007/10/02)
Efficient syntheses are developed for several pyrylium cations with substitution patterns more sterically demanding than 2,4,6-triphenyl and these are examined as reagents for the conversion of primary amino into a leaving group.The 2-mesityl-4,6-diphenyl derivative did not react smoothly with amines.The 2,6-di-t-butyl-4-phenyl-pyrylium cation gave the corresponding pyridinium derivatives, but they resisted nucleophilic attack. 2-t-Butyl-4,6-diphenylpyridinium cations suffer nucleophilic attack with about the same ease as the 2,4,6-triphenyl analogues.Dihydrobenzopyrylium (6) and tetrahydrodibenzoxanthylium cations (7) gave pyridinium cations which underwent much easier nucleophilic attack: thus they alkylate xanthate anion in ethanol solution and acetate anion in acetic acid.
