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1.
Polymers (Basel) ; 16(5)2024 Feb 21.
Article in English | MEDLINE | ID: mdl-38475262

ABSTRACT

A family of pyridine-oxazoline-ligated cobalt complexes L2CoCl23a-h were synthesized and characterized. Determined via single-crystal X-ray diffraction, complexes 3a and 3d, ligated by two ligands, displayed a distorted tetrahedral coordination of a cobalt center. The X-ray structure indicated the pyridine-oxazoline ligands acted as unusual mono-dentate ligands by coordinating only to Noxazoline. Upon activation with AlEt2Cl (diethylaluminum chloride), these cobalt complexes all exhibited high catalytic activity (up to 2.5 × 106 g·molCo-1·h-1), affording cis-1,4-co-3,4-polyisoprene with molecular weights of 4.4-176 kg mol-1 and a narrow Ð of 1.79-3.42, suggesting a single-site nature of the active sites. The structure of cobalt catalysts and reaction parameters, especially co-catalysts and the reaction temperature, all have significant influence on the polymerization activity but not on the microstructure of polyisoprene.

2.
Medicine (Baltimore) ; 102(42): e35745, 2023 Oct 20.
Article in English | MEDLINE | ID: mdl-37861521

ABSTRACT

To evaluate the safety and efficacy of modified Ahmed glaucoma valve (AGV) implantation (long scleral tunnel technique) in the treatment of neovascularization glaucoma (NVG). This retrospective observational case series included 23 patients (23 eyes) diagnosed with NVG secondary to proliferative diabetic retinopathy from January 2020 to June 2021. All 23 cases received anti-vascular endothelial growth factor treatment. Then, after 3 to 7 days, these cases were treated with modified AGV implantation (long scleral tunnel technique) and were followed up for at least 6 months. The best corrected visual acuity, intraocular pressure, numbers of antiglaucoma medications used, and postoperative complications were observed at 1 week and 1, 3, and 6 months after treatment. With treatment, the mean best corrected visual acuity improved significantly (P < .001) from 1.62 ±â€…0.52 logMAR preoperatively to 1.29 ±â€…0.36 logMAR at the 6-month follow-up. The mean postoperative intraocular pressure was significantly lower than that before modified AGV implantation during follow-up period, decreasing from 45.48 ±â€…7.86 mm Hg preoperatively to 14.87 ±â€…1.96 mm Hg at 1 week, 18.39 ±â€…2.25 mm Hg at 1 month, 16.61 ±â€…1.47 mm Hg at 3 months, and 17.48 ±â€…1.38 mm Hg at 6 months (F = 256.646, P < .001). The median number of antiglaucoma medications used by patients also significantly decreased from 3 (3-4) preoperatively to 0 (0-1) at the 6-month follow-up after surgery (Z = -4.248, P < .001). Postoperative complications included hyphema in 2 cases and vitreous hemorrhage in 1 case, and all 3 patients achieved satisfactory recovery with treatment. No drainage tube-related complications occurred among our patients. Long scleral tunnel technique is a safe and effective surgical treatment for NVG with fewer drainage tube-related complications.


Subject(s)
Glaucoma Drainage Implants , Glaucoma , Humans , Glaucoma Drainage Implants/adverse effects , Antiglaucoma Agents , Retrospective Studies , Intraocular Pressure , Treatment Outcome , Postoperative Complications/epidemiology , Postoperative Complications/prevention & control , Postoperative Complications/etiology , Prosthesis Implantation/adverse effects , Prosthesis Implantation/methods , Drainage , Follow-Up Studies
3.
Eur J Med Chem ; 244: 114859, 2022 Dec 15.
Article in English | MEDLINE | ID: mdl-36308778

ABSTRACT

Eleven novel NNN Cu(II) complexes supported by a tridentate bis(imidazo[1,2-α]pyridin-2-yl)pyridine ligand were synthesized and characterized by elemental analysis, HRMS, and X-ray determination. Target prediction and docking studies indicated that these pincer complexes formed hydrogen bonds with Asp33 and Gly35 of Cathepsin D protein, which is highly associated with prognosis of advanced prostate cancer. Furthermore, they exhibited anti-proliferation activity in both androgen-sensitive and androgen-insensitive prostate cancer cells according to WST-1 assay results. Mechanistic study showed that pincer complexes arrested cell cycle progression at G0/G1 phase and inhibited Cathepsin D regulated signaling pathways. Most importantly, new pincer copper complexes significantly inhibited xenograft prostate cancer growth along with a promising in vivo safety profile. In summary, these results suggest the applicability of the developed novel pincer copper complexes as promising anticancer agents for prostate cancer treatment.


Subject(s)
Antineoplastic Agents , Coordination Complexes , Neoplasms , Humans , Copper/chemistry , Cathepsin D , Androgens , Crystallography, X-Ray , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Coordination Complexes/pharmacology , Coordination Complexes/chemistry
4.
Org Biomol Chem ; 20(23): 4815-4825, 2022 06 15.
Article in English | MEDLINE | ID: mdl-35648132

ABSTRACT

A copper-catalyzed, pyrimidine directed regioselective C-H chlorination of indoles with para-toluenesulfonyl chloride (TsCl) has been developed. The reactions proceeded smoothly in the presence of 20 mol% of Cu(OAc)2 as the catalyst and TsCl as the chlorine source, delivering C2-chlorinated indoles with structural diversity in moderate to excellent yields. Mechanistic studies suggested that single electron transfer (SET) from Cu(II) to TsCl accompanied by the release of the p-toluenesulfonyl radical and the related Cu(III)Cl species might be involved in the reactions.


Subject(s)
Copper , Halogenation , Catalysis , Chlorides , Copper/chemistry , Indoles/chemistry
5.
Molecules ; 27(10)2022 May 12.
Article in English | MEDLINE | ID: mdl-35630591

ABSTRACT

We report that the pincer nickel complexes display prostate cancer antitumor properties through inhibition of cell proliferation. Notably, they display better antitumor properties than cisplatin. Mechanistic studies reveal that these pincer nickel complexes trigger cell apoptosis, most likely due to cell cycle arrest. Interestingly, these complexes also inhibit androgen receptor (AR) and prostate-specific antigen (PSA) signaling, which are critical for prostate cancer survival and progression. Our study reveals a novel function of pincer nickel complexes as potential therapeutic drugs in prostate cancer.


Subject(s)
Antineoplastic Agents , Prostatic Neoplasms , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Cell Line, Tumor , Humans , Male , Nickel , Pelvis/pathology , Prostatic Neoplasms/pathology
6.
Dalton Trans ; 51(21): 8350-8367, 2022 May 31.
Article in English | MEDLINE | ID: mdl-35583248

ABSTRACT

A series of new chiral PCN pincer Pd(II) complexes 3a-l with aryl-based (phosphine)-(imidazoline) ligands were conveniently synthesized from readily available starting materials with the key step being phosphination/C-H palladation reaction. All of the new complexes were characterized by 1H NMR, 13C{1H} NMR, 31P{1H} NMR, and elemental analysis. In addition, the molecular structures of complexes 3c, 3e, 3i, and 3k have been determined by X-ray single crystal diffraction analysis. The potential of the obtained pincer Pd(II) complexes in catalytic enantioselective hydrophosphination reaction was examined. With a loading of 5 mol% and in the presence of a KOAc base, complex 3e acted as an active and stereoselective catalyst for hydrophosphination of various 2-alkenoylpyridines with diphenylphosphine, providing optically active pyridine-containing phosphine derivatives with structural diversity in excellent yields with moderate to good enantioselectivities (up to >99 yield and 87% ee).

7.
Chem Asian J ; 17(2): e202101158, 2022 Jan 17.
Article in English | MEDLINE | ID: mdl-34846096

ABSTRACT

Two different types of new phosphinamide α-amino ester derivatives have been prepared in moderate to high yields via ruthenium(II) and rhodium(III)-catalyzed ortho-C-H functionalization under microwave irradiation. Specifically, the ortho-alkenylated phosphinamides were produced through coupling of phosphinamides containing an α-substituted or α,α-disubstituted α-amino ester with internal alkynes under ruthenium catalysis. In contrast, Ru and the more effective Rh-catalyzed coupling of the α-unsubstituted glycine ester phosphinamide with alkynes resulted in formation of oxidative annulation products, phosphaisoquinolin-1-ones. The developed methods feature the use of easily accessible starting materials, short reaction time, exclusive E-stereoselectivity (for ortho-alkenylation) and good functional group tolerance. The alkenylation reaction was readily scaled up to gram scale. Furthermore, the obtained alkenylated phosphinamide could be transformed into P-containing dipeptides through hydrolysis of the ester group in the catalysis product and subsequent condensation with an α-amino ester.


Subject(s)
Rhodium , Ruthenium , Alkynes , Amino Acids , Catalysis , Esters , Microwaves
8.
Org Biomol Chem ; 19(26): 5914, 2021 Jul 07.
Article in English | MEDLINE | ID: mdl-34179918

ABSTRACT

Correction for 'Diastereoselective synthesis of chiral 3-substituted isoindolinones via rhodium(iii)-catalyzed oxidative C-H olefination/annulation' by Xue-Hong Li et al., Org. Biomol. Chem., 2021, DOI: 10.1039/d1ob00656h.

9.
Org Biomol Chem ; 19(26): 5876-5887, 2021 Jul 07.
Article in English | MEDLINE | ID: mdl-34126629

ABSTRACT

A new method for the direct and stereoselective synthesis of 3-substituted isoindolinones via Rh(iii)-catalyzed chiral N-sulfinyl amide directed asymmetric [4 + 1] annulation of benzamides with acrylic esters has been developed. The reaction proceeded through an oxidative C-H olefination and a subsequent cyclization by intramolecular aza-Michael addition, producing a series of diastereoisomeric chiral isoindolinones (20 examples) in generally good yields with a dr value up to 5.5 : 1. The absolute configurations of the newly formed C-stereocenters in the major and minor diastereomers of the catalysis product have been determined by X-ray crystal diffraction analysis to be S and R, respectively. The separation of the major diastereoisomers from the catalysis products and subsequent removal of the N-sulfinyl chiral auxiliary afforded enantiomerically pure (S)-isoindolinones. The application of the obtained (S)-isoindolinones in the synthesis of several biologically active isoindolinones such as (S)-PD172938, (S)-pazinaclone and (S)-pagoclone is presented.

10.
World J Clin Cases ; 9(8): 2001-2007, 2021 Mar 16.
Article in English | MEDLINE | ID: mdl-33748253

ABSTRACT

BACKGROUND: To report the possible reasons for needle perforation and complications related to perforation, as well as the clinical management of subretinal hemorrhage (SRH) during retrobulbar injection. CASE SUMMARY: A 65-year-old female was scheduled to undergo pars plana vitrectomy (PPV) in her left eye for rhegmatogenous retinal detachment (RRD). During retrobulbar anesthesia, needle perforation of the globe occurred. Massive SRH in the inferotemporal quadrant together with vitreous hemorrhage were observed. The patient underwent PPV combined with retinotomy for removal of the massive SRH. After earlier surgical intervention, successful reattachment of the retina was achieved. CONCLUSION: Inadvertent globe penetration during retrobulbar anesthesia is associated with a poor prognosis and may result in blindness. Timely detection and earlier intervention may be beneficial.

11.
J Org Chem ; 85(15): 9525-9537, 2020 08 07.
Article in English | MEDLINE | ID: mdl-32628848

ABSTRACT

Bis(3-indolyl)methanes are well-known natural products with a broad range of important biological functions including cancer cell growth inhibition and antimicrobial activity. Incorporation of a trifluoromethyl group is known to have a profound effect on the parent compound's biological activities. Here, an efficient method for the synthesis of chiral trifluoromethylated bis(3-indolyl)methanes via a catalytic asymmetric Friedel-Crafts (F-C) alkylation reaction has been established. Both enantiomers of the catalysis products can be obtained by tuning the chiral substituents of the catalyst. With 5 mol % of the Ni(II)/(imidazoline-oxazoline) complex as the catalyst, the F-C reaction of indoles with ß-CF3-ß-(3-indolyl)nitroalkenes proceeded well to afford a series of chiral bis(3-indolyl)methanes bearing a trifluoromethylated all-carbon quaternary stereocenter in generally good yields with excellent enantioselectivities (up to 98% yield and 94% ee). Furthermore, by interchanging the indole moieties of the two reactants, indole vs ß-CF3-ß-(3-indolyl)nitroalkene in the F-C reaction, both enantiomers of a given trifluoromethylated bis(3-indolyl)methane were obtained with high enantioselectivities (89-94% ee) upon removal of the indole N-protecting group in the F-C products. The current work represents the first general catalytic enantioselective approach to the important class of trifluoromethylated bis(3-indolyl)methanes.


Subject(s)
Methane , Nickel , Alkylation , Carbon , Catalysis
12.
Org Biomol Chem ; 17(20): 5029-5037, 2019 05 28.
Article in English | MEDLINE | ID: mdl-31045200

ABSTRACT

The first nickel(ii)-catalyzed direct sulfuration/annulation of C(sp2)-H bonds with elemental sulfur has been achieved by using 2-amino alkylbenzimidazole (MBIP-amine) as a N,N-bidentate directing group. This strategy tolerates a wide range of functional groups, furnishing structurally diverse benzoisothiazolone derivatives with benzimidazole skeletons in moderate to excellent yields in a simple and efficient way.

13.
Org Biomol Chem ; 17(25): 6069-6098, 2019 Jun 26.
Article in English | MEDLINE | ID: mdl-31090773

ABSTRACT

Palladium pincer complexes, containing a monoanionic terdentate ligand composed of an anionic aryl carbon atom and two mutually compatible donor sites, have aroused considerable interest since their first reports in the late 1970s. The high stability of the Pd pincer complexes and particularly their high modularity make these species ideal candidates for catalysis. Furthermore, the nature of the meridional coordination of the pincer ligands, and along with this their ability to enforce a stereo-specific environment around the Pd center, provide a good opportunity for developing chiral Pd pincer catalysts. Thus, a broad variety of chiral Pd pincer complexes have been prepared by the introduction of various stereochemical centers in the pincer skeletons. These chiral Pd pincer complexes have been successfully applied to many asymmetric catalytic reactions such as hydrophosphination reactions, allylation of aldehydes and imines, Michael and aldol reactions, Suzuki-Miyaura reactions as well as reactions of nitrile compounds with imines. This review focuses on the synthetic methods and the applications of chiral Pd pincer complexes in asymmetric catalysis.

14.
J Org Chem ; 84(1): 191-203, 2019 01 04.
Article in English | MEDLINE | ID: mdl-30545214

ABSTRACT

The first enantioselective Michael addition of 2-acetyl azaarenes to ß-CF3-ß-(3-indolyl)nitroalkenes has been successfully achieved in the presence of a Co(II)/(imidazoline-oxazoline) complex as the catalyst. The reaction affords a series of CF3- and 3-indole-containing adducts featuring a trifluoromethylated all-carbon quaternary stereocenter in good to excellent yields (up to 99%) and enantioselectivities (up to 96% ee). Furthermore, the functional groups in the adducts including C═O, NO2, and the azaarene provide a large variety of useful transformations, leading to the formation of valuable intermediates such as optically active secondary alcohol, pyrroline, ester, and pyrrolidinone which all contain a 3-substituted indole and a trifluoromethylated all-carbon quaternary stereocenter.

15.
Org Lett ; 19(15): 4042-4045, 2017 08 04.
Article in English | MEDLINE | ID: mdl-28745899

ABSTRACT

The manganese-catalyzed addition of C-2 position of indoles to maleimides has been achieved under additive-free conditions. The manganese catalyst exhibits excellent chemo- and regioselectivity, good functional group compatibility, and high catalytic efficiency. The substrate scope can also be extended to maleates, ethyl acrylate, 1,4-dihydro-1,4-epoxynaphthalene, pyrroles, and 2-phenylpyridine, which further demonstrates the universality of this straightforward approach.

16.
International Eye Science ; (12): 2112-2115, 2017.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-669213

ABSTRACT

AIM:To investigate the curative effect of Shuxuetong injection combined with intravitreal injection of ranibizumab and laser photocoagulation in the treatment of macular edema (ME) secondary to branch retinal vein occlusion (BRVO).METHODS:Totally 70 patients (70 affected eyes) with ME secondary to BRVO treated from January 2015 to December 2016 were randomly divided into the control group and the observation group by random number table method,35 patients (35 affected eyes) in each group.The control group were treated by intravitreal injection of ranibizumab and laser photocoagulation,and on the basis,the observation group were treated with Shuxuetong injection.The clinical curative effect and complications were compared between the two groups.At 1wk,1 and 3mo after treatment,the best corrected visual acuity (BCVA) and central retinal thickness (CRT)were checked again.RESULTS:The total effective rate of treatment in the observation group was slightly higher than that in the control group (91% vs 80%;P>0.05) while the markedly effective rate in the observation group was higher than that in the control group (43% vs20%;P<0.05).At 1wk,1 and 3mo after treatment,BCVA and CMT in the two groups decreased (P<0.05),and they were lower in the observation group than the control group at the same time point (P<0.05).There was no significant difference in the incidence of complications between the two groups (P>0.05).CONCLUSION:The treatment of ME secondary to BRVO with Shuxuetong injection combined with intravitreal injection of ranibizumab and laser photocoagulation can effectively reduce CRT and improve visual acuity,with high safety.

17.
Angew Chem Int Ed Engl ; 54(1): 272-5, 2015 Jan 02.
Article in English | MEDLINE | ID: mdl-25393827

ABSTRACT

The cobalt-catalyzed alkoxylation of C(sp(2) )H bonds in aromatic and olefinic carboxamides has been developed. The reaction proceeded under mild conditions in the presence of Co(OAc)2 ⋅4H2 O as the catalyst and tolerates a wide range of both alcohols and benzamide substrates, including even olefinic carboxamides. In addition, this reaction is the first example of the direct alkoxylation of alkenes through CH bond activation.


Subject(s)
Alcohols/chemistry , Alkenes/chemistry , Amides/chemistry , Cobalt/chemistry , Hydrocarbons, Aromatic/chemistry , Catalysis
18.
J Org Chem ; 79(21): 10399-409, 2014 Nov 07.
Article in English | MEDLINE | ID: mdl-25331644

ABSTRACT

Highly effective CuCl-mediated C-H alkoxylation of arenes and heteroarenes has been developed by using a 2-aminopyridine 1-oxide moiety as an N,O-bidentate directing group. The reaction proceeds smoothly using a broad range of substrates to afford o-alkoxylated benzoic and heteroaromatic amide products. Moreover, the reaction system shows remarkable compatibility when hexafluoroisopropanol is used as a coupling parter; halogen, nitro, ether, alkoxy, ester, and sulfonyl functional groups are all tolerated. The directing group can be easily removed by base hydrolysis, affording o-alkoxylated benzoic acids.


Subject(s)
Aminopyridines/chemistry , Benzoic Acid/chemistry , Copper/chemistry , Cyclic N-Oxides/chemical synthesis , Aminopyridines/chemical synthesis , Catalysis , Cyclic N-Oxides/chemistry , Molecular Structure
19.
J Org Chem ; 79(20): 9512-30, 2014 Oct 17.
Article in English | MEDLINE | ID: mdl-25233005

ABSTRACT

A series of chiral PCN pincer Pd(II) complexes VI-XIII with aryl-based aminophosphine-imidazoline or phosphinite-imidazoline ligands were synthesized and characterized. They were examined as enantioselective catalysts for the hydrophosphination of enones. Among them, complex IX, which features a Ph2PO donor as well as an imidazoline donor with (4S)-phenyl and N-Tol-p groups, was found to be the optimal catalyst. Thus, in the presence of 2-5 mol % of complex IX a wide variety of enones reacted smoothly with diarylphosphines to give the corresponding chiral phosphine derivatives in high yields with enantioselectivities of up to 98% ee. In particular, heteroaryl species such as 2-thienyl-, 2-furyl-, and 2-pyridinyl-containing enones that have a strong coordination ability to the Pd center were also appropriate substrates for the current catalytic system. For example, hydrophosphination of 2-alkenoylpyridines with diphenylphosphine followed by oxidation with H2O2 afforded the corresponding pyridine-functionalized chiral phosphine oxides in good yields with good to excellent enantioselectivities (10 examples, up to 95% ee). Furthermore, it had been demonstrated that the obtained pyridine-containing phosphine oxide acted as a tridentate ligand in the reaction with PdCl2 to form an intriguing NCsp(3)O pincer Pd(II) complex via Csp(3)-H bond activation, which to our knowledge is the first example of a chiral DCsp(3)D' Pd pincer (D ≠ D'; D and D' denote donor atoms such as P, N, etc.).

20.
Org Lett ; 16(4): 1104-7, 2014 Feb 21.
Article in English | MEDLINE | ID: mdl-24502415

ABSTRACT

Copper-mediated selective mono- or diaryloxylation of benzamides has been achieved by using 2-aminopyridine 1-oxide as a new and removable N,O-bidentate directing group. The reaction system shows a broad substrate scope and provides a straightforward way for the synthesis of mono- and diaryloxylated benzoic acids.

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