- Muscarinic agonist, (±)-quinuclidin-3-yl-(4-fluorophenethyl)(phenyl)carbamate: High affinity, but low subtype selectivity for human M1 – M5 muscarinic acetylcholine receptors
-
Novel quinuclidinyl N-phenylcarbamate analogs were synthesized, and binding affinities at M1-M5 muscarinic acetylcholine receptor (mAChR) subtypes were determined using Chinese hamster ovary (CHO) cell membranes stably expressing one
- Lee, Na-Ra,Gujarathi, Satheesh,Bommagani, Shobanbabu,Siripurapu, Kiranbabu,Zheng, Guangrong,Dwoskin, Linda P.
-
-
Read Online
- Atomic Pt-Catalyzed Heterogeneous Anti-Markovnikov C-N Formation: Pt10Activating N-H for Pt1δ+-Activated C-C Attack
-
C-N formation is of great significance to synthetic chemistry, as N-containing products are widely used in chemistry, medicine, and biology. Addition of an amine to an unsaturated carbon-carbon bond is a simple yet effective route to produce new C-N bonds. But how to effectively conduct an anti-Markovnikov addition with high selectivity has been a great challenge. Here, we proposed a strategy for highly regioselective C-N addition via hydroamination by using supported Pt. It has been identified that atomic-scale Pt is the active site for C-N addition with Pt12+ for Markovnikov C-N formation and atomic Pt (Pt1δ+ and Pt10) contributing to anti-Markovnikov C-N formation. A selectivity of up to 92% to the anti-Markovnikov product has been achieved with atomic Pt in the addition of styrene and pyrrolidine. A cooperating catalysis for the anti-Markovnikov C-N formation between Pt1δ+ and Pt10 has been revealed. The reaction mechanism has been studied by EPR spectra and in situ FT-IR spectra of adsorption/desorption of styrene and/or pyrrolidine. It has been demonstrated that Pt10 activates amine to be electrophilic, while Pt1δ+ activates C-C by π-bonding to make β-C nucleophilic. The attack of nucleophilic β-C to electrophilic amine affords the anti-Markovnikov addition. This strategy proves highly effective to a variety of substrates in anti-Markovnikov C-N formation, including aromatic/aliphatic amines reacting with aromatic olefins, aromatic/aliphatic olefins with aromatic amines, and linear aliphatic olefins with secondary aliphatic amines. It is believed that the results provide evidence for the function of varied chemical states in monatomic catalysis.
- Ma, Xiaodan,An, Zhe,Song, Hongyan,Shu, Xin,Xiang, Xu,He, Jing
-
p. 9017 - 9027
(2020/12/23)
-
- Use of (cyclopentadienone)iron tricarbonyl complexes for c-n bond formation reactions between amines and alcohols
-
The application of a series of (cyclopentadienone)iron tricarbonyl complexes to "borrowing hydrogen" reactions between amines and alcohols was completed in order to assess their catalytic activity. The electronic variation of the aromatic groups flanking the C?O of the cyclopentadienone influenced the efficiency of the reactions; however, in other cases, the Kn?lker catalyst 1, containing trimethylsilyl groups flanking the cyclopentadienone ketone, gave the best results. In some cases, the change of the ratio of amine to alcohol improves the conversion significantly. The application of iron catalysts to the synthesis of a range of amines, including unsaturated amines, was investigated.
- Brown, Thomas J.,Cumbes, Madeleine,Diorazio, Louis J.,Clarkson, Guy J.,Wills, Martin
-
p. 10489 - 10503
(2018/05/31)
-
- A ruthenium-based catalytic system for a mild borrowing-hydrogen process
-
The alkylation of arylamines using stoichiometric amounts of aliphatic and benzylic alcohols in the presence of tBuOK was carried out at 55 °C using a low catalyst loading of [Ru(cod)-Cl2]n/PTA (1,3,5-triaza-7-phosphaadamantane). The overall borrowing-hydrogen process does not require a controlled nitrogen atmosphere, and it could also be carried out at room temperature using higher loading of base. A wide range of substrates can be used in this transformation, and it has a good tolerance of different substituents. This catalytic system proved also to be efficient for other hydrogen-transfer reactions such as a tandem oxidation/C-C coupling between 1-phenylethanol and primary alcohols.
- Jumde, Varsha R.,Gonsalvi, Luca,Guerriero, Antonella,Peruzzini, Maurizio,Taddei, Maurizio
-
p. 1829 - 1833
(2015/05/27)
-
- A highly active bifunctional iridium complex with an alcohol/alkoxide- tethered N-heterocyclic carbene for alkylation of amines with alcohols
-
A series of new iridium(III) complexes containing bidentate N-heterocyclic carbenes (NHC) functionalized with an alcohol or ether group (NHC-OR, R=H, Me) were prepared. The complexes catalyzed the alkylation of anilines with alcohols as latent electrophiles. In particular, biscationic IrIII complexes of the type [Cp*(NHC-OH)Ir(MeCN)]2+2[BF4 -] afforded higher-order amine products with very high efficiency; up to >99 % yield using a 1:1 ratio of reactants and 1-2.5 mol % of Ir, in short reaction times (2-16 h) and under base-free conditions. Quantitative yields were also obtained at 50 °C, although longer reaction times (48-60 h) were needed. A large variety of aromatic amines have been alkylated with primary and secondary alcohols. The reactivity of structurally related iridium(III) complexes was also compared to obtain insights into the mechanism and into the structure of possible catalytic intermediates. The IrIII complexes were stable towards oxygen and moisture, and were characterized by NMR, HRMS, single-crystal X-ray diffraction, and elemental analyses. Copyright
- Bartoszewicz, Agnieszka,Marcos, Rocio,Sahoo, Suman,Inge, A. Ken,Zou, Xiaodong,Martin-Matute, Belen
-
supporting information
p. 14510 - 14519
(2013/01/15)
-
- Amination of aromatic olefins with anilines: A new domino synthesis of quinolines
-
A new catalytic amination of aromatic olefins with anilines is presented. In a domino reaction, substituted quinoline derivatives are obtained in the presence of cationic rhodium complexes, such as [Rh(cod)2]BF4, and PPh3. Ethylbenzene is formed as a by-product in this new oxidative reaction. The first transition metal catalyzed anti-Markovnikov hydroamination of styrene with anilines occurs as a side reaction. Mechanistic investigations strongly support the regioselective oxidative amination of styrene as the key reaction step.
- Beller, Matthias,Thiel, Oliver R.,Trauthwein, Harald,Hartung, Christian G.
-
p. 2513 - 2522
(2007/10/03)
-
- Kinetics and Mechanism of Reactions between 2-Phenylethyl Benzenesulphonates and Anilines in Methanol
-
Kinetics of reactions between 2-phenylethyl benzenesulphonates and anilines in methanol at 65.0 deg C have been studied; the mechanism is discussed on the basis of cross interaction constants, ρij.The overall reaction was found to proceed by a dissociative SN2 mechanism with a relatively small degree of aryl participation.The fraction of the phenonium ion intermediate captured by the nucleophile, aniline, in the aryl-assisted pathway has been shown to increase with a stronger nucleophile, and a four-centre transition state in an intermolecular SNi mechanism is suggested for the aryl-unassisted pathway.
- Lee, Ikchoon,Choi, Yong Hoon,Lee, Hai Whang,Lee, Byung Choon
-
p. 1537 - 1540
(2007/10/02)
-
- Antiimplantation Agents: Part II - 1,2-Diaryl-1,2,3,4-tetrahydroisoquinolines
-
1,2-Diaryl-3,4-dihydroisoquinolinium derivatives (5) have been synthesised from N-aryl-N-aroyl-β-phenethylamines (4) and found to exhibit no antiimplantation activity in the rat whereas many of the corresponding tetrahydroisoquinolines (6) are active.Structure-activity relationships have also been studied. 1-(p-Fluorophenyl)-6-methoxy-2-phenyl-1,2,3,4-tetrahydroisoquinoline (6u) and its nor derivative (6v) are very potent, while the ortho (6g) and the meta (6n) fluoro analogues as well as the des-fluoro derivative (6d) are quite active.Extensive biological tests have been carried out on 6g.The enantiomers (+)-6p*HCl and (-)-6q*HCl of 6n have similar activity profiles as that of 6n showing no separation of antiimplantation and estrogenic properties.Diastereomeric 2-(2-methyl-2-phenethyl)-1-phenyl-1,2,3,4-tetrahydroisoquinolines (13a and 13b) show similar properties, while the tetracyclic derivative 19 is inactive. 2-Phenoxyethyl-1-phenyl-1,2,3,4-tetrahydroisoquinoline (26) shows moderate activity, but 1-(β-phenethyl)-2-phenyl-1,2,3,4-tetrahydroisoquinoline 29 is inactive.
- Nagarajan, K.,Talwalker, P. K.,Kulkarni, C. L.,Shah, R. K.,Shenoy, S. J.,Prabhu, S. S.
-
-