Theoretical prediction of relative and absolute pKa values of aminopyridines

Caballero, Norma A.; Meléndez, Francisco J.; Muñoz‐Caro, Camelia; Niño, Alfonso

doi:10.1016/j.bpc.2006.06.007

Cited by 42 publications

(22 citation statements)

References 29 publications

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“…The role of the 2-F or 2-Cl substituent would be to remove electron density, and hence Lewis basicity, from the pyridine ring. And the observed trend is consistent with their measured and calculated p K a values (pyr ∼5.2, 3-Cl-pyr ∼2.8 and 2-Cl-pyr ∼0.7)41.…”

Section: Resultssupporting

confidence: 89%

Asymmetric Suzuki-Miyaura coupling of heterocycles via Rhodium-catalysed allylic arylation of racemates

et al. 2017

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Using asymmetric catalysis to simultaneously form carbon–carbon bonds and generate single isomer products is strategically important. Suzuki-Miyaura cross-coupling is widely used in the academic and industrial sectors to synthesize drugs, agrochemicals and biologically active and advanced materials. However, widely applicable enantioselective Suzuki-Miyaura variations to provide 3D molecules remain elusive. Here we report a rhodium-catalysed asymmetric Suzuki-Miyaura reaction with important partners including aryls, vinyls, heteroaromatics and heterocycles. The method can be used to couple two heterocyclic species so the highly enantioenriched products have a wide array of cores. We show that pyridine boronic acids are unsuitable, but they can be halogen-modified at the 2-position to undergo reaction, and this halogen can then be removed or used to facilitate further reactions. The method is used to synthesize isoanabasine, preclamol, and niraparib—an anticancer agent in several clinical trials. We anticipate this method will be a useful tool in drug synthesis and discovery.

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Section: Resultssupporting

confidence: 89%

Asymmetric Suzuki-Miyaura coupling of heterocycles via Rhodium-catalysed allylic arylation of racemates

et al. 2017

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“…The accuracy of approximation and calculation of new pK a values is characterized most frequently by mean absolute deviation (MAD) [42,50,55,68,74,75,77,83,84,89,92,96,104,108,153,157,203], coefficient of correlation between the calculated and experimental values (r 2 ) [20, 36, 50, 55, 57-60, 74, 76, 89, 104, 149, 152, 154, 155, 157, 159-160, 162-167, 214, 215], and mean-square error (RMSE) [20, 55, 56, 75, 76, 78, 87, 108, 113, 155, 157, 159-160, 162-167, 216]. In addition, the following criteria are used: maximal absolute deviation max(Δ pK a ) [42,50,74,84,92,154], maximal relative deviation max(ε pK a ) [159,160,210,2110], mean relative deviation MRD [153,159,160], sum of squared deviations SSD [104,155], standard deviation SD [51,58,60,74,75,83,96,149,155,…”

Section: Criteria Of the Accuracy And Validity Of The Calculation Modelmentioning

confidence: 99%

“…In addition, the following criteria are used: maximal absolute deviation max(Δ pK a ) [42,50,74,84,92,154], maximal relative deviation max(ε pK a ) [159,160,210,2110], mean relative deviation MRD [153,159,160], sum of squared deviations SSD [104,155], standard deviation SD [51,58,60,74,75,83,96,149,155,190], and Q 2 criterion [56,152,156,157,162,167]:…”

Section: Criteria Of the Accuracy And Validity Of The Calculation Modelmentioning

confidence: 99%

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Modern methods for estimation of ionization constants of organic compounds in solution

Zevatskii

Samoilov²

2011

Russ J Org Chem

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The review considers main up-to-date approaches to the calculation of ionization constants of organic compounds in solutions. Methods based on quantum-chemical calculations, continuum solvent models, cluster models, and quantitative structure-property relationships are discussed. The results of calculations of pK a values by different methods, obtained in the past decade, are compared. REVIEW ACID IONIZATION CONSTANTS AND THEIR SIGNIFICANCEA quantitative parameter of acid-base properties of an HA molecule is the equilibrium constant for proton transfer (K a ) from acid HA to solvent molecule M with formation of lyonium ion and acid anion [1-3] (if an acid is an onium ion, neutral base is formed).

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“…Therefore, they can exist in neutral and protonated for at physiological pH. Aminopyridines pharmacophore and one or more amine groups, being by positive charge on the protonated nitrogen, is suitable for hydrogen bonding 41 . Possible inhibiton mechanisms of the synthesized compounds can be similar to polyamines like spermine.…”

Section: Ca Inhibitionmentioning

confidence: 99%