Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 29
Filter
Add more filters










Publication year range
1.
Arch Esp Urol ; 77(3): 229-234, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38715162

ABSTRACT

BACKGROUND: This work aimed to investigate the potential role of abnormal lipid metabolism in the development of prostate cancer (PCa). METHODS: A retrospective study design was used. The clinical data of 520 patients who underwent rectal prostate biopsy in our hospital from January 2020 to June 2023 were analysed. The patients were enrolled and divided into the anterior PCa group including 112 patients and benign prostatic hyperplasia (BPH) group including 408 patients. Univariate and multivariate logistic regression analyses were performed for the two patient groups, and further comparisons were made according to the Gleason score and TNM staging. RESULTS: Low-density lipoprotein cholesterol (LDL-C) level may be an independent risk factor for PCa, and it was significantly associated with the risk of PCa (odds ratio (OR) = 1.363, p = 0.030). Patients with PCa were further divided into the low risk group and the high risk group according to the Gleason score. Univariate analysis (p = 0.047) and logistic regression analysis (OR = 2.249, p = 0.036) revealed that LDL-C was a significant factor influencing the Gleason score. Patients with PCa were categorised into four groups based on TNM staging. One-way analysis of variance (ANOVA) analysis (p = 0.015) and ordinal logistic regression analysis (OR = 2.414, p = 0.007) demonstrated that LDL-C was a significant factor influencing TNM staging. CONCLUSIONS: This study revealed the important role of LDL-C in the development of PCa, highlighting its influence as an independent risk factor. Thus, LDL-C may promote the proliferation and invasion of PCa cells.


Subject(s)
Cholesterol, LDL , Prostatic Neoplasms , Humans , Male , Retrospective Studies , Prostatic Neoplasms/blood , Prostatic Neoplasms/pathology , Aged , Cholesterol, LDL/blood , Middle Aged , Risk Factors , Neoplasm Grading , Neoplasm Staging
2.
Chem Commun (Camb) ; 59(47): 7255-7258, 2023 Jun 08.
Article in English | MEDLINE | ID: mdl-37222758

ABSTRACT

We developed an electrochemical strategy for the synthesis of quinones through direct oxidation of widely accessible arenes and heteroarenes under mild conditions. A variety of quinones and hetero quinones were prepared with moderate to good yields, without the involvement of the pre-functionalized substrates. In addition, this atom economic method also exhibits wide functional group tolerance, including C(sp2)-I bond, ester, aldehyde, and OTf groups. This synthetic approach provides a straightforward and atom economic method for the transformation of C(sp2)-H bonds.


Subject(s)
Quinones , Oxidation-Reduction
3.
Molecules ; 28(9)2023 Apr 26.
Article in English | MEDLINE | ID: mdl-37175145

ABSTRACT

Spin crossover complexes are a route toward designing molecular devices with a facile readout due to the change in conductance that accompanies the change in spin state. Because substrate effects are important for any molecular device, there are increased efforts to characterize the influence of the substrate on the spin state transition. Several classes of spin crossover molecules deposited on different types of surface, including metallic and non-metallic substrates, are comprehensively reviewed here. While some non-metallic substrates like graphite seem to be promising from experimental measurements, theoretical and experimental studies indicate that 2D semiconductor surfaces will have minimum interaction with spin crossover molecules. Most metallic substrates, such as Au and Cu, tend to suppress changes in spin state and affect the spin state switching process due to the interaction at the molecule-substrate interface that lock spin crossover molecules in a particular spin state or mixed spin state. Of course, the influence of the substrate on a spin crossover thin film depends on the molecular film thickness and perhaps the method used to deposit the molecular film.

4.
J Phys Condens Matter ; 35(36)2023 Jun 08.
Article in English | MEDLINE | ID: mdl-37216948

ABSTRACT

Using optical characterization, it is evident that the spin state of the spin crossover molecular complex [Fe{H2B(pz)2}2(bipy)] (pz = tris(pyrazol-1-1y)-borohydride, bipy = 2,2'-bipyridine) depends on the electric polarization of the adjacent polymer ferroelectric polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) thin film. The role of the PVDF-HFP thin film is significant but complex. The UV-Vis spectroscopy measurements reveals that room temperature switching of the electronic structure of [Fe{H2B(pz)2}2(bipy)] molecules in bilayers of PVDF-HFP/[Fe{H2B(pz)2}2(bipy)] occurs as a function of ferroelectric polarization. The retention of voltage-controlled nonvolatile changes to the electronic structure in bilayers of PVDF-HFP/[Fe{H2B(pz)2}2(bipy)] strongly depends on the thickness of the PVDF-HFP layer. The PVDF-HFP/[Fe{H2B(pz)2}2(bipy)] interface may affect PVDF-HFP ferroelectric polarization retention in the thin film limit.

5.
J Org Chem ; 88(9): 5248-5253, 2023 May 05.
Article in English | MEDLINE | ID: mdl-37023248

ABSTRACT

Direct para-selective C(sp2)-H alkylation of electron-deficient arenes based on the electroreduction-enabled radical addition of alkyl bromides has been developed under mild conditions. In the absence of any metals and redox agents, the simple electrolysis system tolerates a variety of primary, secondary, and tertiary alkyl bromides and behaves as an important complement to the directed alkylation of the C(sp2)-H bond and the classic Friedel-Crafts alkylation. This electroreduction process provides a more straightforward, environmentally benign, and effective alkylation method for electron-deficient arenes.

6.
Chemistry ; 29(29): e202300367, 2023 May 22.
Article in English | MEDLINE | ID: mdl-36905399

ABSTRACT

A straightforward synthesis approach to chiral 1-aryl-2-aminoethanols via the one-pot asymmetric hydrogenation catalyzed by Ir catalyst was developed. This tandem process involves the in situ generation of α-amino ketones via the nucleophilic substitution of α-bromoketones with amines and the Ir-catalyzed asymmetric hydrogenation of ketone intermediates to provide diverse enantiomerically enriched ß-amino alcohols. The excellent yields and enantioselectivities (up to 96 % yield and up to >99 % ee) with a wide substrate scope in this one-pot strategy were obtained.

7.
J Org Chem ; 88(5): 2942-2951, 2023 Mar 03.
Article in English | MEDLINE | ID: mdl-36787380

ABSTRACT

An iridium catalytic system with a ferrocene-based phosphine ligand bearing a modular and tunable unsymmetrical vicinal diamine scaffold was developed for the asymmetric hydrogenation of aryl ketones. This approach provided a powerful tool for the enantioselective synthesis of diverse chiral alcohols with excellent reactivity and enantioselectivity (up to 99% yield, up to 99% ee, and up to 50,000 turnover number). The substituents and chirality of unsymmetrical diamines in ligands played an important role in the satisfactory results.

8.
Nanoscale ; 15(5): 2044-2053, 2023 Feb 02.
Article in English | MEDLINE | ID: mdl-36597843

ABSTRACT

Future molecular microelectronics require the electronic conductivity of the device to be tunable without impairing the voltage control of the molecular electronic properties. This work reports the influence of an interface between a semiconducting polyaniline polymer or a polar poly-D-lysine molecular film and one of two valence tautomeric complexes, i.e., [CoIII(SQ)(Cat)(4-CN-py)2] ↔ [CoII(SQ)2(4-CN-py)2] and [CoIII(SQ)(Cat)(3-tpp)2] ↔ [CoII(SQ)2(3-tpp)2]. The electronic transitions and orbitals are identified using X-ray photoemission, X-ray absorption, inverse photoemission, and optical absorption spectroscopy measurements that are guided by density functional theory. Except for slightly modified binding energies and shifted orbital levels, the choice of the underlying substrate layer has little effect on the electronic structure. A prominent unoccupied ligand-to-metal charge transfer state exists in [CoIII(SQ)(Cat)(3-tpp)2] ↔ [CoII(SQ)2(3-tpp)2] that is virtually insensitive to the interface between the polymer and tautomeric complexes in the CoII high-spin state.

9.
Chem Commun (Camb) ; 58(96): 13345-13348, 2022 Dec 01.
Article in English | MEDLINE | ID: mdl-36373836

ABSTRACT

A three-component reductive coupling reaction of aldehydes, amines and cyanopyridines under electrochemical conditions has been developed. The in situ generated imine and cyanopyridine simultaneously undergo single-electron reduction at the cathode, and afford diarylmethylamines through radical coupling without the participation of reducing agents. The one-pot electrolysis method can modularly obtain various secondary and tertiary amines and exhibits broad functional group compatibility. Mechanistic experiments verify the pivotal reduction step from imine to α-amino radical and reveal the key role of benzoic acid in reducing the reduction potential of imine and cyanopyridine.


Subject(s)
Amines , Electricity , Catalysis , Amination , Imines
10.
J Org Chem ; 87(19): 12677-12687, 2022 Oct 07.
Article in English | MEDLINE | ID: mdl-36102897

ABSTRACT

A general method for the synthesis of phenols from electron-deficient aryl ammonium salts or heteroaryl ammonium salts under mild conditions was developed. Benzaldehyde oxime, acetohydroxamic acid, and hydroxylamine hydrochloride were investigated as hydroxide surrogates respectively. With these hydroxide surrogates, a series of phenols were prepared in yields of 20-98%.

11.
Nat Commun ; 13(1): 4138, 2022 07 16.
Article in English | MEDLINE | ID: mdl-35842447

ABSTRACT

By merging electricity with sulfate, the Ritter-type amination of C(sp3)-H bonds is developed in an undivided cell under room temperature. This method features broad substrate generality (71 examples, up to 93% yields), high functional-group compatibility, facile scalability, excellent site-selectivity and mild conditions. Common alkanes and electron-deficient alkylbenzenes are viable substrates. It also provides a straightforward protocol for incorporating C-deuterated acetylamino group into C(sp3)-H sites. Application in the synthesis or modification of pharmaceuticals or their derivatives and gram-scale synthesis demonstrate the practicability of this method. Mechanistic experiments show that sulfate radical anion, formed by electrolysis of sulfate, served as hydrogen atom transfer agent to provide alkyl radical intermediate. This method paves a convenient and flexible pathway for realizing various synthetically useful transformations of C(sp3)-H bonds mediated by sulfate radical anion generated via electrochemistry.


Subject(s)
Sulfates , Amination , Catalysis , Electrochemistry , Molecular Structure
12.
J Phys Condens Matter ; 34(29)2022 May 19.
Article in English | MEDLINE | ID: mdl-35508146

ABSTRACT

Compact domain features have been observed in spin crossover [Fe{H2B(pz)2}2(bipy)] molecular thin film systems via soft x-ray absorption spectroscopy and photoemission electron microscopy. The domains are in a mixed spin state that on average corresponds to roughly 2/3 the high spin occupation of the pure high spin state. Monte Carlo simulations support the presence of intermolecular interactions that can be described in terms of an Ising model in which interactions beyond nearest-neighbors cannot be neglected. This suggests the presence of short-range order to permit interactions between molecules beyond nearest neighbor that contribute to the formation of largely high spin state domains structure. The formation of a spin state domain structure appears to be the result of extensive cooperative effects.

13.
Org Biomol Chem ; 20(19): 3897-3901, 2022 05 18.
Article in English | MEDLINE | ID: mdl-35481827

ABSTRACT

A nucleophilic aromatic substitution (SNAr) reaction that allowed transition-metal-free C-P bond construction via C-N bond cleavage was developed. The coupling between aryltrimethylammonium salts and secondary phosphines from the in situ reduction of diarylphosphine oxides led to the formation of diverse triarylphosphines with various functional groups. This one-pot process was not only a pertinent SNAr precedent but also a favorable transition-metal-free alternative for C-P coupling.


Subject(s)
Phosphines , Transition Elements , Molecular Structure , Oxides/chemistry , Phosphines/chemistry , Salts/chemistry
14.
Org Lett ; 24(17): 3205-3210, 2022 05 06.
Article in English | MEDLINE | ID: mdl-35451304

ABSTRACT

A practical continuous flow protocol has been developed using readily accessible N-(tert-butylsulfinyl)-bromoimine and Grignard reagents, providing various functionalized piperidines (34 examples) in superior results (typically >80% yield and with >90:10 dr) within minutes. The high-performance scale-up is smoothly carried out, and efficient synthesis of the drug precursor further showcases its utility. This flow process offers rapid and scalable access to enantioenriched α-substituted piperidines.


Subject(s)
Piperidines , Indicators and Reagents , Stereoisomerism
15.
Chem Commun (Camb) ; 58(5): 661-664, 2022 Jan 13.
Article in English | MEDLINE | ID: mdl-34914817

ABSTRACT

The [Co(SQ)2(4-CN-py)2] complex exhibits dynamical effects over a wide range of temperature. The orbital moment, determined by X-ray magnetic circular dichroism (XMCD) with decreasing applied magnetic field, indicates a nonzero critical field for net alignment of magnetic moments, an effect not seen with the spin moment of [Co(SQ)2(4-CN-py)2].

16.
Commun Chem ; 5(1): 63, 2022 May 19.
Article in English | MEDLINE | ID: mdl-36697664

ABSTRACT

Chiral γ-amino alcohols are the prevalent structural motifs and building blocks in pharmaceuticals and bioactive molecules. Enantioselective hydrogenation of ß-amino ketones provides a straightforward and powerful tool for the synthesis of chiral γ-amino alcohols, but the asymmetric transformation is synthetically challenging. Here, a series of tridentate ferrocene-based phosphine ligands bearing modular and tunable unsymmetrical vicinal diamine scaffolds were designed, synthesized, and evaluated in the iridium-catalyzed asymmetric hydrogenation of ß-amino ketones. The system was greatly effective to substrates with flexible structure and functionality, and diverse ß-tertiary-amino ketones and ß-secondary-amino ketones were hydrogenated smoothly. The excellent reactivities and enantioselectivities were achieved in the asymmetric delivery of various chiral γ-amino alcohols with up to 99% yields, >99% ee values, and turnover number (TON) of 48,500. The gram-scale reactions with low catalyst loading showed the potential application in industrial synthesis of chiral drugs, such as (S)-duloxetine, (R)-fluoxetine, and (R)-atomoxetine.

17.
Org Lett ; 23(24): 9387-9392, 2021 12 17.
Article in English | MEDLINE | ID: mdl-34881901

ABSTRACT

We develop an electrochemical nickel-catalyzed aminomethylation of aryl bromides under mild conditions. The convergent paired electrolysis makes full use of anode and cathode processes, free of a terminal oxidant, a sacrificial anode, a metal reductant, and a prefunctionalized radical precursor. In addition, this method exhibits wide functional group tolerance (63 examples), including some sensitive substituents and aromatic heterocycles. This redox neutral cross coupling provides a more environmentally friendly and synthetic practical protocol for forging C(sp2)-C(sp3) bonds.

18.
ACS Omega ; 6(26): 16847-16853, 2021 Jul 06.
Article in English | MEDLINE | ID: mdl-34250344

ABSTRACT

The synthesis of gold nanoparticles is dependent on both the concentration of trisodium citrate dihydrate and the time that it interacts with tetrachloroauric acid. A wide range of gold nanoparticles with various sizes and dispersity can be produced based on control variables, such as time of reaction and acid concentration, using a similar approach to that of the Turkevich model. In this model, the pH of the solution decreases slightly throughout the reaction (0.005 unit/min) due to the chemical interactions between trisodium citrate dihydrate and tetrachloroauric acid. Dicarboxy acetone is formed during citrate oxidization, resulting in gold nuclei formation over time. In addition, gold nanoparticle nucleation causes pH fluctuation over time based on gold nanoparticle sizes. An inverse correlation (coefficient of smaller than -0.97) was calculated between the pH and reaction time at different ratios of trisodium citrate dihydrate to tetrachloroauric acid. Regression analysis was used to develop a model for the prediction of the size of gold nanoparticles ranging from 18 to 38 nm based on the concentration of trisodium citrate dihydrate and the reaction time.

20.
RSC Adv ; 11(31): 19021-19028, 2021 May 24.
Article in English | MEDLINE | ID: mdl-35478625

ABSTRACT

Aliphatic polyesters are biocompatible materials that can be used in biomedical applications. We report here the use of tetrabutylammonium phthalimide-N-oxyl catalyst (TBAPINO), as a thermally stable organocatalyst for the ring-opening polymerization (ROP) of cyclic esters under mild conditions. In the solution ROP of ε-caprolactone (ε-CL), quantitative conversion and M n of ∼20 000 g mol-1 are achieved in a wide temperature range from -15 to 60 °C. Under bulk condition, the conversion of ε-CL reaches over 85% at 120 °C within 2 h. The living ROP character of l-lactide (l-LA) catalyzed over TBAPINO is proved by multiple additions of monomer in the bulk polymerization. The catalyst shows comparable selectivity towards the ring-opening polymerization of l-LA and ε-CL. Their copolymerization over TBAPINO is carried out in one-pot bulk condition in terms of the reaction time, monomer feed ratio, and sequence of addition. The colorless poly(ε-caprolactone-co-lactide) (PCLA) is obtained with considerable conversion of both monomers with the M n over 22 000 g mol-1.

SELECTION OF CITATIONS
SEARCH DETAIL
...