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1.
Org Biomol Chem ; 21(31): 6307-6311, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37492010

RESUMO

A new method has been successfully developed that offers a facile and reliable approach for synthesizing (E)-2-(1-(methoxyimino)ethyl)-2-phenylbenzofuran-3(2H)-one, providing 28 compounds. This optimized process enables efficient preparation of a wide range of compounds using readily available (E)-1-(benzofuran-2-yl)ethan-1-one O-methyl oxime and iodobenzene, and provides alternative ideas for the structural modification of benzofuran ketones.

2.
Dalton Trans ; 52(26): 8964-8974, 2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37326416

RESUMO

A novel bis-bidentate nitronyl nitroxide radical based on triazolopyrimidine, NIT-2-TrzPm (NIT-2-TrzPm = (2-(2'-triazolopyrimidine)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxy-3-oxide)) and six new transition metal complexes of this ligand, namely [M(hfac)2(NIT-2-TrzPm)]·CH2Cl2 (M = Mn (1Mn) and Co (2Co)), [M(hfac)2]2(NIT-2-TrzPm) (M = Mn (3Mn) and Co (4Co)), [Mn(NIT-2-TrzPm)2(MeOH)2](ClO4)2·MeOH (5Mn), and [Co(NIT-2-TrzPm)2(MeOH)2]2(ClO4)4·4MeOH (6Co) were prepared and characterized structurally and magnetically. These complexes can be selectively synthesized by controlling the reaction ratio of M(hfac)2·2H2O to the radical ligand (for 1Mn to 4Co) or using metal perchlorates as the starting materials (for 5Mn and 6Co). Single crystal X-ray crystallographic analyses confirmed that 1Mn and 2Co are isostructural 3d-2p MII-radical complexes, in which the NIT-2-TrzPm radical acts as a terminal bidentate ligand chelating to one 3d ion, while 3Mn and 4Co are isostructural 3d-2p-3d MII-radical-MII complexes with the NIT-2-TrzPm radical acting as a bridging ligand between two 3d ions. For complexes 5Mn and 6Co, two NIT-2-TrzPm ligands from the equatorial positions coordinate with the metal center to form the 2p-3d-2p structures with the axial positions occupied by two methanol molecules. Magnetic analysis on the MnII complexes revealed the existence of a strong antiferromagnetic interaction between the MnII and the NIT radical spin, while weak ferromagnetic coupling for Mn⋯Mn and Rad⋯Rad in the Mn-NIT-Mn and Rad-Mn-Rad spins was confirmed. Interestingly, although the NIT-bridged complexes 3Mn and 4Co possess significantly different magnetic anisotropy, field-induced slow magnetic relaxation can be observed in both complexes, which was assigned to the phonon bottleneck effect for 3Mn and field-induced SMM behavior for 4Co. To the best of our knowledge, 3Mn is the first example of the NIT-bridged binuclear MnII complex undergoing slow magnetic relaxation.

3.
Inorg Chem ; 61(32): 12726-12735, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35905478

RESUMO

Four iron(III) complexes, [Fe(qsal-4-F)2]Y·sol (Hqsal-4-F = 4-fluoro-N-(8-quinolyl)salicylaldimine; Y = NO3-, sol = 0.91MeOH·0.57H2O (1NO3); Y = PF6- (2PF6); Y = BF4- (3BF4); Y = OTf-, sol =1.5MeOH (4OTf)), with a new 4-position substituted qsal type ligand Hqsal-4-F have been synthesized and structurally and magnetically characterized. Complexes 1NO3-3BF4 consist of 1D chains formed by the [Fe(qsal-4-F)2]+ cations connected by π-π and C-H···O interactions, which are further linked by more weak interactions to form 2D layers and 3D networks. On the other hand, complex 4OTf has a structure of nearly isolated 1D column where the [Fe(qsal-4-F)2]+ cations are connected by π-π, C-H···π, and C-F···π interactions. Magnetic studies revealed the occurrence of two-step symmetry-breaking SCO in 1NO3 and two-step gradual SCO in 2PF6. Complex 3BF4 undergoes a gradual SCO, whereas 4OTf remains almost high-spin. The smaller anions tend to stabilize the low-spin state, while larger anions tend to stabilize the high-spin state. In addition, the intermediate spin state of 1NO3 could be thermally trapped by quenching from the high temperature, thereby kinetically suppressing the spin transition to the full low-spin state. This work represents a good example that the position of the substituent and the anions plays critical roles in the preparation of SCO materials with tunable properties.

4.
Dalton Trans ; 51(32): 12362-12372, 2022 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-35904351

RESUMO

Two new bis-bidentate imidazole-substituted nitronyl nitroxide biradicals, BNITIm-C2 (BNITIm-C2 = 1,1'-(1,2-ethanediyl)bis(1H-imidazole-2-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxy-3-oxide)) and BNITIm-C4 (BNITIm-C4 = 1,1'-(1,4-butanediyl)bis(1H-imidazole-2-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxy-3-oxide)), and two series of lanthanide complexes, namely [(BNITIm-C2)Ln(NO3)3](MeOH) (Ln = Gd (1Gd) and Tb (2Tb)), (BNITIm-C2)Dy(NO3)3 (3Dy) and (BNITIm-C4)[Ln(hfac)3]2(C7H8)2 (Ln = Gd (4Gd), Tb (5Tb) and Dy (6Dy), hfac = hexafluoroacetylacetonate), have been prepared and characterized structurally and magnetically. Single crystal X-ray crystallographic analyses revealed that complexes 1Gd-3Dy exhibit 1D chain structures where the Ln(NO3)3 units are bridged by the BNITIm-C2 bis-bidentate biradical, while complexes 4Gd-6Dy exhibit binuclear structures with two Ln(hfac)3 units bridged by the BNITIm-C4 biradical. The bulky hfac anions prohibit the further coordination of LnIII to another NIT ligand and the formation of a similar 1D chain structure. Due to the very long intra- and intermolecular distances of the spin centers, complexes 1Gd-3Dy can be magnetically regarded as an isolated 2p-4f-2p tri-spin system while complex 4Gd-6Dy can be regarded as an isolated 2p-4f bi-spin system. Magnetic analyses on the two GdIII compounds revealed the ferromagnetic GdIII-NIT interactions and antiferromagnetic NIT-NIT interactions through the GdIII ion in 1Gd. Alternating-current (ac) magnetic susceptibility investigations revealed that complex 5Tb exhibits the typical SMM behavior under a zero dc field while complex 6Dy was proved to be a field-induced SMM. Ab initio calculations were performed on complexes 2Tb and 5Tb to understand their magnetic anisotropy together with their different magnetic dynamics.

5.
Org Biomol Chem ; 18(39): 7922-7931, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33001107

RESUMO

A novel method for the Rh(iii)-catalyzed oxime-directed C-H amidation of indoles with dioxazolones has been developed. This strategy provides an exclusive site selectivity and the directing group can be easily removed. This transformation features a wide substrate scope, good functional group tolerance and excellent yields, and may serve as a significant tool to construct structurally diverse indole derivatives for the screening of potential pharmaceuticals in the future.

6.
RSC Adv ; 10(67): 41041-41046, 2020 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-35519175

RESUMO

Herein we report an oxidative coupling reaction for N-S/S-S bond formation from (E)-N'-benzylideneacetohydrazide and S8 to furnish substituted N,N'-disulfanediyl-bis(N'-((E)-benzylidene) acetohydrazide). It provides a direct approach for the synthesis of disulfides with good yields.

7.
Org Biomol Chem ; 17(29): 7055-7065, 2019 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-31304943

RESUMO

An efficient copper-mediated ortho-C(sp2)-H thiolation of aromatic amides directed by a novel directing group [4-chloro-2-(1H-pyrazol-1-yl)phenyl]amine has been developed without the need of other additives or oxidants, allowing for an increased usefulness. With the high compatibility of sterically demanding substrates, this reaction is scalable and can tolerate a wide scope of functional groups to provide alkyl and aryl thioethers in good to excellent yields (up to 93%). Furthermore, the protocol has been successfully implemented for the selenylation as well.

8.
World J Gastroenterol ; 22(43): 9525-9533, 2016 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-27920473

RESUMO

AIM: To determine the expression and localization of the electrogenic Na+/HCO3- cotransporter (NBC1) in rat pancreas during development. METHODS: The rat pancreas from postnatal and embryos removed from the uterus of pregnant rats that had been sacrificed by CO2 asphyxiation were used. Rat pancreas from embryonic day (E) 15.5 and E18.5 rat embryos was isolated under a stereomicroscope. Rat pancreas from postnatal (P) days 0, 7, 14, 21 and adult was directly isolated by the unaided eye. The RT-PCR analysis of the NBC1 specific region on rat pancreas tissues from different developmental stages. The two antibodies which target the NBC1 common COOH-terminal region and NH2-terminal region detected a clear band of about 145 kDa in the Western blot analysis. The localization of NBC1 was examined by immuno-fluorescence detection. RESULTS: The results revealed the first peak of NBC1 expression at E18.5 and the second peak at P14. Meanwhile, the low NBC1 expression occurred at P7 and adult stages. Our results demonstrated, for the first time, the presence of NBC1 in the plasma membrane of ß and α cells, as well as in the basolateral membrane of acinar cells of the rat pancreas at different stages of development. CONCLUSION: The data strongly suggests that NBC1 is diversely expressed in the pancreas at different developmental stages, where it may exert its functions in pancreatic development especially islet cell growth through HCO3- transport and pH regulation.


Assuntos
Células Secretoras de Glucagon/metabolismo , Células Secretoras de Insulina/metabolismo , Pâncreas/metabolismo , Simportadores de Sódio-Bicarbonato/metabolismo , Fatores Etários , Animais , Animais Recém-Nascidos , Western Blotting , Imunofluorescência , Regulação da Expressão Gênica no Desenvolvimento , Idade Gestacional , Morfogênese , Pâncreas/embriologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Simportadores de Sódio-Bicarbonato/genética
9.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 10): o2580, 2010 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-21587562

RESUMO

In the title compound, C(11)H(13)NO(4), the two fused rings are almost coplanar, making a dihedral angle of 3.02 (8)°. In the crystal, chains are formed parallel to [010] through N-H⋯O hydrogen bonds between the amine and carbonyl groups.

10.
Yao Xue Xue Bao ; 44(5): 486-90, 2009 May.
Artigo em Chinês | MEDLINE | ID: mdl-19618723

RESUMO

Quantitative structure-property relationships (QSPR) were developed to predict the pK(a) values of sulfa drugs via heuristic method (HM) and gene expression programming (GEP). The descriptors of 31 sulfa drugs were calculated by the software CODESSA, which can calculate constitutional, topological, geometrical, electrostatic, and quantum chemical descriptors. HM was also used for the preselection of 4 appropriate molecular descriptors. Linear and nonlinear QSPR models were developed based on the HM and GEP separately and two prediction models lead to a good correlation coefficient (R) of 0.90 and 0.95. The two QSPR models are tseful in predicting pK(a) during the discovery of new drugs and providing theory information for studying the new drugs.


Assuntos
Algoritmos , Modelos Químicos , Software , Sulfonamidas/química , Expressão Gênica , Relação Quantitativa Estrutura-Atividade
11.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 3): o456, 2009 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-21582128

RESUMO

The title compound, C(21)H(33)NO, crystallizes with three independent mol-ecules in the asymmetric unit. The cyclo-hexane and piperidine rings adopt chair conformations. The crystal packing is stabilized by inter-molecular O-H⋯N and C-H⋯O hydrogen bonds, and by weak π-π stacking inter-actions [centroid-centroid distance = 3.876 (2) Å].

12.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 1): o116, 2008 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-21581578

RESUMO

In the title compound, C(8)H(12)N(4)O(4), the essentially planar methyl-carbamoyloxymethyl group [maximum deviation 0.038 (3) Å] and the imidazole ring make a dihedral angle of 48.47 (3)°. The crystal packing is stabilized by inter-molecular N-H⋯N and C-H⋯O hydrogen bonds, which link the mol-ecules into infinite ribbons running along the a axis, and by weak π-π stacking inter-actions [centroid-centroid distance = 3.894 (2) Å].

13.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 1): o182, 2007 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-21200746

RESUMO

In the title compound, C(11)H(8)N(2)O(2), the packing is consolidated by C-H⋯N and C-H⋯O inter-actions.

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