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Katayev EA Boev NV Myshkovskaya E Khrustalev VN Ustynyuk YA 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(29):9065-9073
The anion-templated syntheses and binding properties of novel macrocyclic oligopyrrole receptors in which pyrrole rings are linked through amide or imine bonds are described. The efficient synthesis was accomplished by anion-templated [1+1] Schiff-base condensation and acylation macrocyclization reactions. Free receptors and their host-guest complexes with hydrochloric acid, acetic acid, tetrabutylammonium chloride, and hydrogen sulfate were analyzed by single-crystal X-ray diffraction analysis. Stability constants with different tetrabutylammonium salts of inorganic acids were determined by standard 1H NMR and UV/Vis titration techniques in [D6]DMSO/0.5% water solution. According to the titration data, receptors containing three pyrrole rings (10 and 12) exhibit high affinity (log Ka=5-7) for bifluoride, acetate, and dihydrogen phosphate, and interact weakly with chloride and hydrogen sulfate. The amido-bipyrrole receptors 11 and 13 with four pyrrole rings exhibit 10(4)- and 10(2)-fold selectivity for dihydrogen phosphate, respectively, as inferred from competitive titrations in the presence of tetrabutylammonium acetate. 相似文献
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Diiminodipyrromethane complexes of Ni, Pd, and Pt are able to activate O2, resulting in a metal-dependent autoxidation of the ligand. 相似文献
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Nadezhda V. Stoletova Andrey D. Moshchenkov Alexander F. Smol'yakov Zalina T. Gugkaeva Victor I. Maleev Dmitry Katayev Vladimir A. Larionov 《Helvetica chimica acta》2021,104(1):e2000193
Perfluoroalkylated α-amino acids (PFAAs) are a unique class of compounds for biochemistry and pharmaceutical science. In this context, we report the successful intermolecular coupling of the Belokon’s chiral dehydroalanine Ni(II) complex with a variety of perfluoroalkyl iodides. A 4-cyanopyridine/B2Pin2 catalytic system generates perfluoroalkyl radicals, which after trapping by the ligand sphere of a chiral Ni(II) complex provide the diastereomeric complexes with up to >20 : 1 dr (seven examples). The obtained major (S,S)-diastereomers were easily isolated by simple silica column chromatography in 33–54 % yields. The perfluoroalkylated α-AA was subsequently released from the obtained Ni(II) complex through aqueous HCl treatment. The chiral auxiliary ligand ((S)-BPB=(S)-2-(N-benzylprolyl)aminobenzophenone) can be easily recycled after the acidic complex decomposition and reused for the synthesis of the starting dehydroalanine Ni(II) complex. 相似文献
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A palladium‐catalyzed intramolecular α‐arylation of an amide in the presence of a bulky chiral N‐heterocyclic carbene ligand is the key step in the first catalytic synthesis of (3R)‐6‐chloro‐3‐(3‐chlorobenzyl)‐1,3‐dihydro‐3‐(3‐methoxyphenyl)‐2H‐indol‐2‐one ((R)‐ 5 ). This oxindole, in racemic form, had been shown previously to be an anticancer agent. (R)‐ 5 was obtained with an overall yield of 45% and with 96% enantioselectivity. 相似文献
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Roxan Calvo Aleix Comas‐Vives Antonio Togni Dmitry Katayev 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(5):1461-1466
Demonstrated herein is the construction of trifluoromethylated quaternary carbon centers by an asymmetric radical transformation. Enantioenriched trifluoromethylated oxindoles were accessed using a hypervalent iodine‐based trifluoromethyl transfer reagent in combination with a magnesium Lewis acid catalyst and PyBOX‐type ligands to achieve up to 99 % ee and excellent chemical yields. Mechanistic studies were performed by experimental and computational methods and suggest a single‐electron transfer induced SN2‐type mechanism. This example is thereby the first report on the construction of enantioenriched trifluoromethylated carbon centers using hypervalent iodine‐based reagents proceeding through such a reaction pathway. 相似文献
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Evgeny A. Katayev Yuri A. Ustynyuk Jonathan L. Sessler 《Coordination chemistry reviews》2006,250(23-24):3004
This review covers the field of anion recognition from the perspective of tetrahedral oxyanion recognition. The bulk of the attention is devoted to metal-free systems that are able to effect the recognition, binding or transport of phosphate and sulfate. Particular emphasis is devoted to design criteria that allow for discrimination and selectivity. In this context, a variety of recognition motifs are discussed and, within each receptor class, general paradigms that allow for the construction of receptor systems with high affinity and specificity are noted. 相似文献