¿Utilizan los alumnos esquemas conceptuales en la interpretación del sonido?

The origin of this work can be traced to investigations that have centred on the students' previous knowledge that conditions their learning process. There are, however, two aspects which must be taken into account: firstly, to know about the students' previous ideas should no be considered as an end in itself but as the starting point towards deliberate intervention and, secondly, when someone uses his knowledge, he does it with conceptual structures and with certain strategies related to them. Our work concentrates on the identification of the students' ideas (both conceptual and procedural) about one of the few areas to which not many contributions have been made: the learning of sound. We attempt to identify the possible schemes the students use in their interpretation of aspects related to their everyday life. Finally, we establish certain implications for the teaching of these contents in compulsory secondary Education

Planificación de una unidad didáctica : el estudio del movimiento

In this study we attempt to apply an outline of Teaching Units for the study of Cinematics at Secondary Level. Having analysed the teaching problems indicated by teachers, the scientific contents involved and the methodological problems, a sequence of learning contents is established from a creative construction perspective

Eight-membered Palladacycles Derived from the Insertion of Olefines into the Pd–C Bond of Ortho-palladated Pharmaceuticals Phenethylamine and Phentermine. Synthesis of Stable Heck-type Intermediates Containing Accessible β-Hydrogens and its Use in the Synthesis of 2-Styryl-phenethylamines, Tetrahydroisoquinolines and Eight-membered Cyclic Amidines

This document is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by /4.0/This document is the Accepted Manuscript version of a Published Work that appeared in final form in Organometallics copyright © American Chemical Society, after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/om100738zThe ortho-metalated complexes derived from phenethylamine and phentermine [Pd(C,N-C6H4CH2CR2NH2-2)(μ-X)]2 (R = H, X = Br (A); R = Me, X = Cl (B)) react with olefins giving (1) the product of its insertion into the Pd–C bond, [Pd{C,NCH( R’)CH2C6H4CH2CR2NH2-2}(μ-X)]2 (olefin = CH2=CHR’; R = H, X = Cl, R’ = C(O)Me (1a), CO2Et (1c); R = Me, X = Cl, R’ = C(O)Me (1b), CO2Et (1d)), [Pd{C,NCH( C5H8)CHC6H4(CH2CMe2NH2)-2}(μ-Cl)]2 (olefin = norbornene, C5H8; 1e) or (2) the decomposition products of 1, i.e., Pd(0) and the complexes containing the arylated olefin, trans-[PdX2(NH2CR2CH2C6H4CH=CHPh-2)2] (olefin = styrene; R = H, X = Cl (3f); R = Me, X = Br (3g)). While complexes 1c and 1d can be isolated but decompose in solution to afford Pd(0) and the corresponding complexes 3 (R = H, X = Cl (3c); R = Me, X = Br (3d)), the others are surprisingly stable. Neutral ligands L cleave the bridge of complexes 1 to afford [Pd(C^N)X(L)] (2) (L = 4-methyl-pyridine (pic), NH3, NHEt2, PPh3, tBuNC, XyNC). Complexes 3 react with 1,10-phenanthroline (phen) to give [PdX2(phen)] and the orthovinylated arylalkylamine RCH=CHC6H4CH2CR2NH2-2 (R = H (4f), Me (4g)), which in the case of 3c or 3d can not be isolated as it undergoes an intramolecular hydroamination process to afford the tetrahydroisoquinoline 5c or 5d, respectively. To prepare the tetrahydroisoquinoline 5b, it is necessary to heat a mixture of complex 1b with one equiv of TlOTf. The eight-membered cyclic amidine 7d is obtained from thermal decomposition of complex cis-[Pd{C,N-CH(CO2Et)CH2C6H4CH2CR2NH2-2}(CNXy)2]OTf (8d), prepared by reaction of 2d-5 with TlOTf and XyNC. The amidinium salt 7e-HOTf is formed by refluxing in toluene a mixture of 2e-4 and TlOTf. The crystal structures of compounds 2a·CHCl3, 2b-1, 3 2d-3·1/3CH2Cl2, 2e-4·1/2CHCl3, 3d, 3g, 6 and 7e-HOTf have been determined by X-ray diffraction studies

Insertion of benzyne into the Pd–C bond. Synthesis of unnatural amino acid derivatives by sequential insertion of benzyne and CO: 2,2’-functionalized biaryls containing alkylamino and carboxymethyl substituents. Isolation of stable carbopalladated-benzyne intermediates

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Chemical Communications, copyright © Royal Society of Chemistry after peer review and technical editing by the publisher. This document is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by /4.0/Reaction of ortho-palladated derivatives of phentermine and homoveratrylamine with benzyne allows the synthesis of enlarged eight-membered palladacycles resulting from the insertion of the aryne into the Pd–C bond, which subsequently react with CO, to render unnatural amino acid derivatives

Reactivity toward CO of Eight-Membered Palladacycles Derived from the Insertion of Alkenes into the Pd–C Bond of Cyclopalladated Primary Arylalkylamines of Pharmaceutical Interest. Synthesis of Tetrahydrobenzazocinones, Ortho-Functionalized Phenethylamines, Ureas, and an Isocyanate

This document is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by /4.0/. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Organometallics copyright © American Chemical Society, after peer review and technical editing by the publisher.The ortho-metalated complex [Pd{C,N-C6H2CH2CH2NH2-2,(OMe)2-4,5}(μ-Br)]2 (1a) derived from homoveratrylamine reacts with ethyl acrylate, methyl vinyl ketone or 2-norbornene to give the dimeric complex arising from the insertion of the alkene into the Pd–C bond, [Pd{C,N-CH(R)CH2C6H2CH2CH2NH2-2,(OMe)2-4,5}(μ-Br)]2 (R = CO2Et (2a1), C(O)Me (2a2)) or [Pd{C,N-CH(C5H8)CHC6H2CH2CH2NH2-2,(OMe)2-4,5}(μ-Br)]2 (2a3). Complexes 2a and the phentermine homologues 2b react with CO to afford Pd(0) and (1) tetrahydrobenzazocinones, the heterocycles resulting from CO insertion into the Pd–C bond and C–N coupling, (2) unnatural aminoacid derivatives resulting from CO insertion and the reaction of the obtained acyl complex with the solvent (MeOH), or the product of protonolysis of the Pd–C bond, depending on the nature of the initial cyclopalladated compound or (3) ureas, alone or mixed with an isocyanate, in the presence of a base. Phentermine derivatives 2b react with HCl to give a dinuclear palladium complex [PdCl(μ- Cl)(L)], where L is the amine arising from the protonolysis of the Pd–C bond or the alkyl group resulting from Pd–N bond protonolysis, depending on the nature of the inserted alkene. The crystal structures of some palladium complexes and organic compounds have been determined by X-ray diffraction studies

A New Method for High Yield Cyclopalladation of Primary and Secondary Amines. Atom-Efficient Open-to-Air Inexpensive Synthesis of Buchwald-Type Precatalysts

This document is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by /4.0/ This document is the Accepted Manuscript version of a Published Work that appeared in final form in Organometallics copyright © American Chemical Society, after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/om200464sA new method for high yield cyclopalladation of primary and secondary amines involving the corresponding ammonium triflates, instead of the amines generally employed is reported. The method is applied for the synthesis of Buchwald-type precatalysts [Pd(C,N-C6H4CH2CH(R’)NHR- 2)X(phosphine)] that can be easily prepared by reaction of Pd(OAc)2, one equiv of the ammonium triflate [PhCH2CH(R’)NH2R]OTf and an excess of NaX, and then treating the resulting complexes [Pd2(C,N-C6H4CH2CH(R’)NHR-2)2(μ-X)2] with the appropriate phosphine. This new method has several advantages over Buchwald´s reported synthesis