56542-89-3Relevant academic research and scientific papers
Palladium-catalyzed regioselective arylation of 1,1,3-triaryl-2-azaallyl anions with aryl chlorides
Li, Minyan,Berritt, Simon,Walsh, Patrick J.
, p. 4312 - 4315 (2014)
A regioselective arylation of 1,1,3-triaryl-2-azaallyl anions with aryl chlorides is described. The palladium-NIXANTPHOS-based catalyst affords diarylmethylamine derivatives in good yield and without product isomerization. A gram scale sequential one-pot ketimine synthesis/arylation protocol was also developed.
Synthesis of diarylmethylamines via palladium-catalyzed regioselective arylation of 1,1,3-triaryl-2-azaallyl anions
Li, Minyan,Yuecel, Baris,Adrio, Javier,Bellomo, Ana,Walsh, Patrick J.
, p. 2383 - 2391 (2014/05/20)
Diarylmethylamines are of great interest due to their prevalence in pharmaceutical chemistry. As a result, new methods for their synthesis are in demand. Herein, we report a versatile protocol for the synthesis of diarylmethylamine derivatives involving palladium-catalyzed arylation of in situ generated 2-azaallyl anion intermediates. The 2-azaallyl anions are generated by reversible deprotonation of readily available aldimine and ketimine precursors. Importantly, the arylated aldimine and ketimine products do not undergo isomerization under the reaction conditions. Scale-up of the arylation and hydrolysis of the resulting products to furnish diarylmethylamines were also successfully performed. This journal is the Partner Organisations 2014.
Metal 4-alkylidene-4H-pyridin-1-ides and 2H-imidazol-4-ones from novel highly N-(pyridin-4-yl)methyl-substituted azomethines
Hampe, Diana,Guenther, Wolfgang,Goerls, Helmar,Anders, Ernst
, p. 4357 - 4372 (2007/10/03)
Novel azomethines 3 synthesized from 4-(aminomethyl)pyridine (1) and various ketones 2 exhibit a higher acidity of the Ca-protons compared with other 4-alkylpyridines like 4-benzylpyridine or 4-(tosylmethyl)pyridine. Therefore, they can easily be metalated to give a variety of specific anions 3(-), which deserve interest for further synthetic applications. Important properties of compounds 3 and their lithiated derivatives 4 (lithium 4H-pyridin-1-ides, synthesized by deprotonation of the α-CH2 group in 3) can be controlled by the carbonyl reactant 2. These carbanions 3(-) are remarkable intermediates regarding their NMR properties. Comparing the NMR spectra of the lithium 4H-pyridin-1-ides 4 with their parent azomethines 3 reveal very distinct changes in the chemical shifts from which important structural and electronic properties of the carbanions can be deduced. The observation of E/Z isomers in the case of 3c and their mutual conversion at higher temperature inspire DFT calculations on the B3LYP/6-311++G(d,p) level of theory to get insight into the energetic demand of such isomerization processes. Moreover, calculations on the same level of theory were carried out on the model azomethine anion 5 and different monomeric lithium coordination isomers 6a-d. Experimentally, two selected examples will exemplify the reactivity of 4H-pyridin-1-ide anions towards heterocumulenes. The 2-(pyridin-4-yl)acetate 7 obtained from the reaction of 4e with carbon dioxide appears to be a CO2 storage molecule as it easily releases CO2 under protolysis conditions comparable with the vitamin B6 reaction mode. Interesting five-membered heterocycles were isolated after reaction of 4 with isocyanates followed by hydrolysis and oxidation. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
