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1.
Article in English | MEDLINE | ID: mdl-34501916

ABSTRACT

BACKGROUND: The "effort character" (EC) is a resistance training method without reaching muscle failure. It was defined by González-Badillo and Gorostiaga Ayestarán (2002) as the relationship between the repetitions performed and the repetitions achievable. Then, the EC is at its maximum (i.e., 100%) when the subject realizes all the repetitions possible in a series with any load. Therefore, an EC of 50% indicates execution of 50% of the repetitions achievable in a series. This study aimed to determine the effects of two programs of eight weeks of concurrent training (CT) with different EC over muscle strength (MS), cardiorespiratory fitness (CRF), functional mobility (FM), health-related quality of life (HRQoL), and lipid profile (LP) among hospital workers. METHODS: Fourteen hospital workers (age: 41.1 ± 10.8 years; body mass: 63.0 ± 10.8 kg; height: 165.2 ± 6.5 cm; body mass index (BMI): 23.0 ± 3.4 kg/m2) were randomly assigned to an EC 50% (n = 7) or EC 100% (n = 7) group. RESULTS: The main finding was that both groups significantly improved in MS and FM levels but not HRQoL, with no statistical differences between EC 50% and EC 100% in adherence and any test despite performing half the volume of the strength workout. CONCLUSIONS: An eight-week CT program with different EC (i.e., EC 50% vs. EC 100%) seems to improve the MS and FM levels in hospital workers similarly. These findings could be very useful in health-training practices because of the possibility of planning training loads with half the volume of strength workouts without the loss of any training adaptation.


Subject(s)
Quality of Life , Resistance Training , Adult , Hospitals , Humans , Lipids , Middle Aged , Muscle Strength , Muscle, Skeletal , Physical Fitness
2.
Org Lett ; 22(10): 3979-3984, 2020 05 15.
Article in English | MEDLINE | ID: mdl-32338923

ABSTRACT

α,ß-Unsaturated α'-alkoxy ketones have been prepared under mild conditions from allenes using water as the oxygen source and without the necessity of metals. The organocatalytic oxygenation-rearrangement sequence displays an exquisite chemo-, stereo-, and site-selectivity as well as good functional group compatibility. DFT calculations suggest that stabilizing noncovalent Se···O interactions may be responsible for the observed reactivity.

3.
Nanomaterials (Basel) ; 9(4)2019 Apr 08.
Article in English | MEDLINE | ID: mdl-30965642

ABSTRACT

The goal of this research was to obtain high-density single-walled carbon nanotube forests (SWNTs) on conductive substrates for different applications, including field emission. For this, dip-coating was chosen as the catalyst deposition method, to subsequently grow SWNTs by Alcohol Catalytic Chemical Vapor Deposition (AC-CVD). Si (100) was chosen as the substrate, which was then coated with a TiN thin film. By sputtering with Ar, it was possible to generate alternating TiN and Si lanes, with a different wettability and, therefore, a different affinity for the catalysts. As a result, the Mo‒Co catalyst was mainly deposited on TiN and not on sputtered-Si, which allowed the selective growth of SWNT forests on the TiN conductive surfaces. These as-synthesized SWNTs were used for field emission measurements in a high vacuum chamber.

4.
Chemistry ; 23(55): 13754-13759, 2017 Oct 04.
Article in English | MEDLINE | ID: mdl-28786148

ABSTRACT

2-Pyrrolines and 6-oxo-hexa-2,4-dienals have been prepared through the divergent reactions of 1-benzenesulfonyl-4-aryl-1,2,3-triazoles with functionalized allenes. The rhodium-catalyzed reactions between allenols and 1-benzenesulfonyl-4-aryl-1,2,3-triazoles yielded 2-pyrrolines. This transformation is compatible with the presence of aliphatic, aromatic, heterocyclic, amide, and halogen functional groups. Interestingly, a reactivity switch took place when the allene-tethered alcohol substrate was replaced by its ketone counterpart. When the rhodium-catalyzed reaction of 1-benzenesulfonyl-4-phenyl-1,2,3-triazole was performed with allenones, acyclic 6-oxo-hexa-2,4-dienals were stereoselectively formed as (2Z,4E) isomers.

5.
Chemistry ; 23(13): 3012-3015, 2017 Mar 02.
Article in English | MEDLINE | ID: mdl-28106927

ABSTRACT

Switchable reactivity through cationic gold-based catalyst control built on the oxidation state, namely cationic AuIII versus AuI , has been achieved in the direct functionalization of 2-azetidinone-tethered alkynyl indoles.


Subject(s)
Alkynes/chemistry , Azetidines/chemistry , Gold/chemistry , Indoles/chemistry , Lactams/chemistry , Alkynes/chemical synthesis , Azetidines/chemical synthesis , Catalysis , Cations/chemistry , Indoles/chemical synthesis , Lactams/chemical synthesis , Oxidation-Reduction
6.
Chemistry ; 22(33): 11667-76, 2016 Aug 08.
Article in English | MEDLINE | ID: mdl-27383332

ABSTRACT

Controlled preparation of tri- and tetrasubstituted furans, as well as carbazoles has been achieved through chemo- and regioselective metal-catalyzed cyclization reactions of cumulenic alcohols. The gold- and palladium-catalyzed cycloisomerization reactions of cumulenols, including indole-tethered 2,3,4-trien-1-ols, to trisubstituted furans was effective, due to a 5-endo-dig oxycyclization by attack of the hydroxy group onto the central cumulene double bond. In contrast, palladium-catalyzed heterocyclization/coupling reactions with 3-bromoprop-1-enes furnished tetrasubstituted furans. Also studied was the palladium-catalyzed cyclization/coupling sequence involving protected indole-tethered 2,3,4-trien-1-ols and 3-bromoprop-1-enes that exclusively generated trisubstituted carbazole derivatives. These results could be explained through a selective 6-endo-dig cumulenic hydroarylation, followed by aromatization. DFT calculations were carried out to understand this difference in reactivity.

7.
Chem Commun (Camb) ; 52(67): 10265-8, 2016 Aug 11.
Article in English | MEDLINE | ID: mdl-27468860

ABSTRACT

The diastereoselective synthesis of strained adducts that show cage-like structures has been accomplished directly from allenyl-ß-lactams through gold catalysis.

8.
Chem Commun (Camb) ; 52(41): 6813-6, 2016 May 21.
Article in English | MEDLINE | ID: mdl-27126127

ABSTRACT

The synthesis of 2-allenyl-2-substituted-3,3-difluoroindolines has been accomplished, taking advantage of the reaction between N-allenyl-indoles and Selectfluor under iron catalysis.

9.
J Org Chem ; 80(9): 4650-60, 2015 May 01.
Article in English | MEDLINE | ID: mdl-25880256

ABSTRACT

Gold-catalyzed hydroarylation reaction of ß-lactam-tethered allenyl indoles gives azeto-oxepino[4,5-b]indol-2-ones, tetrahydroazeto-azocino[3,4-b]indol-2-ones, and hexahydroazeto-azepino[3,4-b]indol-2-ones with very high levels of stereo- and regioselectivity, the 7-exo and 8-endo carbocyclization modes by attack of the indole group toward either the internal or the terminal allene carbon, respectively, being favored. Hydroarylation across the central carbon of the allene moiety has not been detected. The controlled gold-catalyzed annulations allowed the formation of fused ß-lactams without harming the sensitive four-membered heterocycle. Besides, a novel gold-catalyzed domino process, namely, the allenic hydroarylation/N1-C4 ß-lactam bond breakage to afford dihydro-oxepino[4,5-b]indole-4-carboxamides, has been discovered.


Subject(s)
Alkadienes/chemistry , Gold/chemistry , Indoles/chemistry , Indoles/chemical synthesis , beta-Lactams/chemistry , Catalysis , Molecular Conformation
10.
Chemistry ; 21(4): 1533-41, 2015 Jan 19.
Article in English | MEDLINE | ID: mdl-25418081

ABSTRACT

The divergent behavior of two homologue allenals, namely, 2-(buta-2,3-dienyloxy)- and 2-(propa-1,2-dienyloxy)benzaldehydes, as cyclization substrates is described. 2-(Buta-2,3-dienyloxy)benzaldehydes suffers a formal allenic carbocyclization reaction to afford chromenes, whereas 2-(propa-1,2-dienyloxy)benzaldehydes react to yield chromones. The formation of chromenes is strictly a formal hydroarylation process divided into two parts, namely, allenic Claisen-type rearrangement and oxycyclization. An unknown N-heterocyclic carbene (NHC)-catalyzed allenic hydroacylation reaction must be invoked to account for the preparation of chromones. ortho-Allenylbenzaldehydes bearing either electron-donating substituents or electron-withdrawing substituents worked well to afford both the hydroarylation and hydroacylation products. This unexpected difference in reactivity can be rationalized by means of density functional theory calculations.

11.
Chemistry ; 19(42): 14233-44, 2013 Oct 11.
Article in English | MEDLINE | ID: mdl-24038421

ABSTRACT

Starting from ß,γ-allendiols and α-allenic acetates, a chemo- and regiocontrolled palladium-catalyzed methodology has provided access to enantiopure 3,6-dihydropyrans that bear a buta-1,3-dienyl moiety. Thus, it has been demonstrated for the first time that the preparation of six-membered heterocycles through cross-coupling reactions of two different allenes can be accomplished. These heterocyclization/cross-coupling reactions have been developed experimentally and their mechanisms have additionally been investigated by a computational study.


Subject(s)
Heterocyclic Compounds/chemical synthesis , Palladium/chemistry , Pyrans/chemical synthesis , Cyclization , Esters , Heterocyclic Compounds/chemistry , Molecular Structure , Pyrans/chemistry , Quantum Theory , Stereoisomerism
12.
J Org Chem ; 78(18): 8956-65, 2013 Sep 20.
Article in English | MEDLINE | ID: mdl-24007239

ABSTRACT

The gold-catalyzed preparation of 2-azetidinone-fused oxacycles was accomplished from ß-lactam-linked enynes through heterocyclization reaction taking advantage of the acetonide pendant group. While the synthesis of fused tetrahydrofuran-ß-lactams from 1,3-enynes could be considered as an unusual metal-catalyzed cyclization of enynols, α-alkoxy dioxolane-tethered 1,3-enynes exclusively undergo bis-oxycyclization to afford tricyclic bridged acetals.


Subject(s)
Alkynes/chemistry , Dioxolanes/chemistry , Gold/chemistry , beta-Lactams/chemical synthesis , Catalysis , Cyclization , Molecular Conformation , beta-Lactams/chemistry
13.
Chem Commun (Camb) ; 49(71): 7779-81, 2013 Sep 14.
Article in English | MEDLINE | ID: mdl-23880706

ABSTRACT

3-Substituted (indol-2-yl)-α-allenols show divergent patterns of reactivity under metal catalysis. An unprecedented intramolecular 1,3-iodine migration is described.


Subject(s)
Iodine/chemistry , Metals/chemistry , Carbazoles/chemical synthesis , Carbazoles/chemistry , Catalysis , Cations/chemistry , Crystallography, X-Ray , Cyclization , Molecular Conformation
14.
Chem Commun (Camb) ; 49(13): 1282-4, 2013 Feb 14.
Article in English | MEDLINE | ID: mdl-23295954

ABSTRACT

The divergent gold-catalysed reactivity (C(sp(2))-H versus C(sp(3))-H) of aryloxy-tethered allenes has been uncovered.


Subject(s)
Alkadienes/chemistry , Gold/chemistry , Alkylation , Catalysis , Models, Molecular , Molecular Conformation
15.
Org Biomol Chem ; 10(37): 7603-9, 2012 Oct 07.
Article in English | MEDLINE | ID: mdl-22903552

ABSTRACT

A stereoselective synthesis of 1-substituted (E)-2-aryl-but-1-en-3-ynes, including tetrasubstituted alkenes, has been developed from aryl-substituted α-allenols by treatment with the AcCl-NaOH (aqueous) system. This transformation might be explained through the elimination of acetic acid, made up of a δ-hydrogen and the acetate group in the initially formed α-allenic acetate.


Subject(s)
Alcohols/chemistry , Alkynes/chemical synthesis , Alkynes/chemistry , Molecular Structure , Stereoisomerism
16.
Nanoscale Res Lett ; 7(1): 210, 2012 Apr 10.
Article in English | MEDLINE | ID: mdl-22490731

ABSTRACT

Hollow magnetite microspheres have been synthesized by a simple process through a template-free hydrothermal approach. Hollow microspheres were surface modified by coating with a silica nanolayer. Pristine and modified hollow microparticles were characterized by field-emission electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, FT-IR and Raman spectroscopy, and VSM magnetometry. The potential application of the modified hollow magnetite microspheres as a drug carrier was evaluated by using Rhodamine B and methotrexate as model drugs. The loading and release kinetics of both molecules showed a clear pH and temperature dependent profile. GRAPHICAL Hollow magnetite microspheres have been synthesized. Load-release experiments with Rhodamine-B as a model drug and with Methotrexate (chemotherapy drug used in treating certain types of cancer) demonstrated the potential applications of these nanostructures in biomedical applications.

17.
Chemistry ; 17(52): 15005-13, 2011 Dec 23.
Article in English | MEDLINE | ID: mdl-22135236

ABSTRACT

An efficient chemodivergent metal-controlled methodology for the generation of different highly functionalized oxygen heterocycles from common enallenol substrates has been developed. Chemoselectivity control in the O-C functionalization of an enallenol can be achieved through the choice of catalyst: AuCl(3), PdCl(2), and [PtCl(2)(CH(2)=CH(2))](2) exclusively afford dihydrofurans through selective activation of the allenol moiety, whereas FeCl(3) solely gives tetrahydrofurans or tetrahydropyrans through selective activation of the alkenol moiety. We have also shown that a combination of metal-mediated hydroalkoxylation and allenic aminocyclization reactions can lead to a useful preparation of the tetrahydrofuro[3,2-b]piperidine core of the antimalarial alkaloid isofebrifugine. These divergent heterocyclization reactions have been developed experimentally and additionally, their mechanisms have been investigated by a theoretical study.


Subject(s)
Alcohols/chemistry , Alkenes/chemistry , Furans/chemistry , Gold/chemistry , Metals/chemistry , Platinum/chemistry , Catalysis , Cyclization , Molecular Structure
18.
Nanoscale Res Lett ; 6: 495, 2011 Aug 17.
Article in English | MEDLINE | ID: mdl-21849077

ABSTRACT

Amorphous Si nanowires have been directly synthesized by a thermal processing of Si substrates. This method involves the deposition of an anodic aluminum oxide mask on a crystalline Si (100) substrate. Fe, Au, and Pt thin films with thicknesses of ca. 30 nm deposited on the anodic aluminum oxide-Si substrates have been used as catalysts. During the thermal treatment of the samples, thin films of the metal catalysts are transformed in small nanoparticles incorporated within the pore structure of the anodic aluminum oxide mask, directly in contact with the Si substrate. These homogeneously distributed metal nanoparticles are responsible for the growth of Si nanowires with regular diameter by a simple heating process at 800°C in an Ar-H2 atmosphere and without an additional Si source. The synthesized Si nanowires have been characterized by field emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman.

19.
Chem Commun (Camb) ; 47(32): 9054-6, 2011 Aug 28.
Article in English | MEDLINE | ID: mdl-21766120

ABSTRACT

A novel reactivity in gold catalysis, namely the unusual preference for the 4-exo-dig cyclization in allene chemistry as well as the rare ß-hydride elimination reaction, was uncovered starting from readily available allenols.

20.
Angew Chem Int Ed Engl ; 50(35): 8105-9, 2011 Aug 22.
Article in English | MEDLINE | ID: mdl-21751319

ABSTRACT

Enantioenriched fluorinated heterocycles can be prepared through fluorocyclizations of prochiral indoles (see scheme; Ts=tosyl, Bn=benzyl, Boc=tert-butoxycarbonyl). More than twenty examples for this cascade fluorination-cyclization, which is catalyzed by cinchona alkaloids and employs N-fluorobenzenesulfonimide as the electrophilic fluorine source have been explored, and an unprecedented catalytic asymmetric difluorocyclization has also been identified.

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