Thermal rearrangement of 5,6,6-triphenylbicyclo[3.1.0]hex-2-ene to 6,7-benzo-1,5-diphenyltricyclo[3.2.1.02,8]octane

1980 ◽  
Vol 58 (3) ◽  
pp. 210-213 ◽  
Author(s):  
Stefan Weigl ◽  
John Warkentin
Keyword(s):  
Ring Opening ◽  
The Other ◽  
Thermal Rearrangement ◽  
Initial Formation ◽  
Hydrogen Shift ◽  
Benzene Rings ◽  
Shielding Properties

The triphenyl vinylcyclopropane system, 5,6,6-triphenylbicyclo[3.1.0]hex-2-ene, 1, undergoes clean thermal rearrangement, at 210 °C, to 6,7-benzo-1,4-diphenyltricyclo[3.2.1.02,8]octane, 9. This result indicates that 1 behaves like a phenylcyclopropane and not like a vinylcyclopropane in the thermal ring opening. The proposed mechanism involves initial formation of a 1,3-diradical, one site of which is benzyl as well as homoallyl and the other site of which is both benzhydryl and homoallyl. Subsequent steps involve coupling of the radical sites through one of the phenyl groups and a suprafacial 1,5-hydrogen shift concerted with generation of a new cyclopropane ring.The 1Hmr and 13Cmr spectra of 9 are reported and discussed in terms of the shielding properties of cyclopropane and benzene rings.

scholarly journals Crystal structure of 4-({5-[(E)-(3,5-difluorophenyl)diazenyl]-2-hydroxybenzylidene}amino)-2,2,6,6-tetramethylpiperidin-1-oxyl

2015 ◽  
Vol 71 (7) ◽  
pp. 864-866
Author(s):  
Ramazan Tatsız ◽  
Veli T. Kasumov ◽  
Tuncay Tunc ◽  
Tuncer Hökelek
Keyword(s):  
Dihedral Angle ◽  
Three Dimensional ◽  
Chair Conformation ◽  
The Other ◽  
Supramolecular Network ◽  
Stacking Interactions ◽  
Asymmetric Unit ◽  
Compound C ◽  
Benzene Rings ◽  
Independent Molecules

The asymmetric unit of the title compound, C22H25F2N4O2, contains two crystallographically independent molecules. In one molecule, the two benzene rings are oriented at a dihedral angle of 1.93 (10)° and in the other molecule the corresponding dihedral angle is 7.19 (9)°. The piperidine rings in the two molecules adopt a similar distorted chair conformation, and both have pseudo-mirror planes passing through the N—O bonds. An intramolecular O—H...N hydrogen bond between the hydroxy group and the imine N atom is observed in both molecules. In the crystal, weak C—H...O and C—H...F hydrogen bonds, enclosingR22(6) ring motifs, and weak π–π stacking interactions link the molecules into a three-dimensional supramolecular network, with centroid-to-centroid distances between the nearly parallel phenyl and benzene rings of adjacent molecules of 3.975 (2) and 3.782 (2) Å.

scholarly journals Ações de Docência com Uso de Tecnologias Digitais na Formação Inicial de Professores de Matemática

2020 ◽  
Vol 13 (2) ◽  
pp. 211-221
Author(s):  
Ivanete Fátima Blauth ◽  
Suely Scherer
Keyword(s):  
Teaching Practice ◽  
Basic Education ◽  
Digital Technologies ◽  
Pedagogical Knowledge ◽  
The Other ◽  
Mathematical Content ◽  
Initial Formation ◽  
Practice Teaching ◽  
Teaching Learning ◽  
School Space

ResumoNeste artigo discutimos resultados de uma pesquisa em que se analisou ações propostas em uma disciplina de Prática de Ensino, identificando aquelas que podem ter possibilitado a construção de conhecimentos tecnológicos e pedagógicos de conteúdo, por egressos de um curso de Licenciatura em Matemática. Dentre as ações identificadas, duas são relacionadas à aprendizagem da docência, uma vivenciada na sala de aula da disciplina, em que o acadêmico teve colegas como alunos, e a outra realizada no espaço da escola, em que o acadêmico assumiu a regência de uma aula de matemática em escolas de Educação Básica. O objetivo neste artigo é analisar essas duas ações e possíveis relações com a construção de conhecimentos tecnológicos e pedagógicos de conteúdo matemático. Os dados foram produzidos na pesquisa a partir de entrevistas realizadas com 27 egressos desse curso de Licenciatura em Matemática, que realizaram a disciplina de Prática de Ensino e concluíram o curso, no período de 2010 a 2015. A partir da análise de “falas de egressos”, concluiu se que as duas ações propostas na disciplina de Prática de Ensino, nas quais os professores em formação tiveram a oportunidade de praticar a docência, podem ter oportunizado a construção de conhecimentos tecnológicos e pedagógicos de conteúdo matemático. Nessas ações, esses egressos tiveram que estudar conteúdos matemáticos e tecnologias, de maneira a atender objetivos de aulas e favorecer a aprendizagem de seus alunos.Palavras-chave: Prática de Ensino. Formação Inicial. Matemática. Tecnologias Digitais.AbstractIn this paper we discuss the results of a research in which actions proposed in a Teaching Practice discipline were analyzed, identifying those may have made the construction of technological and pedagogical knowledge, by graduates of a Mathematics Degree. Among the actions identified, two are related to teaching learning, and other experienced in the classroom, in which the students was the academic’s colleagues, and the other was in the school space, in which the academic took over the conduct of a class of mathematics in Basic Education schools. The objective of this article is to analyze these two actions and possible relationships with the construction of technological and pedagogical knowledge of Mathematical content. The data were produced in the research based on interviews with 27 graduates of this Mathematics Degree, who took the Teaching Practice discipline and completed the course, from 2010 to 2015. From the analysis of the “speeches of graduates”, it was concluded that the two actions proposed in the Teaching Practice discipline, in which the teachers in training had the opportunity to practice teaching, may have given rise to the construction of technological and pedagogical knowledge of Mathematical content. In these actions, these graduates had to study Mathematical content and technologies, in order to meet class objectives and favor the learning of their students.Keywords: Teaching Practice. Initial Formation. Mathematics. Digital Technologies.

scholarly journals 4-[5-(Furan-2-yl)-3-trifluoromethyl-1H-pyrazol-1-yl]benzenesulfonamide

2012 ◽  
Vol 68 (4) ◽  
pp. o1168-o1169
Author(s):  
Abdullah M. Asiri ◽  
Hassan M. Faidallah ◽  
Khalid A. Alamry ◽  
Seik Weng Ng ◽  
Edward R. T. Tiekink
Keyword(s):  
Hydrogen Bond ◽  
Benzene Ring ◽  
Torsion Angle ◽  
Title Compound ◽  
Furan Ring ◽  
Pyrazole Ring ◽  
The Other ◽  
Dihedral Angles ◽  
Compound C ◽  
Benzene Rings

In the title compound, C14H10F3N3O3S, there are significant twists in the molecule, as seen in the values of the dihedral angles between the pyrazole ring and each of the furan [31.1 (2)°] and benzene rings [55.58 (10)°]. The amino N atom occupies a position almost normal to the benzene ring [N—S—Car—Car(ar = aromatic) torsion angle = 83.70 (19)°]. One amino H atom forms a hydrogen bond to the tricoordinate pyrazole N atom and the other interacts with a sulfonamide O atom, forming a supramolecular chain along [010]. The chains are consolidated into a supramolecular layersviaC—H...O interactions involving the second sulfonamide O atom; layers stack along [10-1]. The furan ring was found to be disordered over two diagonally opposite orientations of equal occupancy.

Semiconductive Properties of Alternating Mg/C Multi-layer Films with Hydroxylation Treatment

2012 ◽  
Vol 1494 ◽  
pp. 197-202
Author(s):  
Masafumi Chiba ◽  
Daisuke Endo ◽  
Kenichi Haruta ◽  
Hideki Kimura ◽  
Hideo Kiyota
Keyword(s):  
Electrical Conductivity ◽  
Optical Properties ◽  
Water Vapor ◽  
The Other ◽  
Film Sample ◽  
Atmospheric Water ◽  
Initial Formation ◽  
Number Of Layers ◽  
Conductive Film ◽  
Subsequent Exposure

ABSTRACTA Mg(OH)2–C transparent conductive film was prepared using the sputtering method by the initial formation of a Mg-C film generated by the alternate layering of Mg and C on a rotating substrate and subsequent exposure of the film to atmospheric water vapor. To examine the influence exerted by the Mg/C layers of the starting film sample on semiconductivity,evaluations of the electrical conductivity properties of the film during the hydroxylation process and the optical properties after the hydroxylation process were carried out. As a result, although no effects on the characteristics of the electrical conductivity properties associated with the composition or number of layers in the films could be confirmed, it was determined that the films possessed the characteristics of semiconductors. On the other hand, the optical properties were found to be affected by the composition and number of layers of the Mg/C films.

scholarly journals Stereochemical Effect of the Small Ring Unit in 7-R-3,4-Cyclopropano- and 7-R-3,4-Epoxy-bicyclo[4.2.0]octan-1,5-Dienes on Conrotatory Ring Opening Torquoselectivity

2021 ◽  
Author(s):  
Veejendra Yadav
Keyword(s):  
Activation Energy ◽  
Ring Opening ◽  
Energy Approach ◽  
The Other ◽  
Small Ring ◽  
Formyl Group ◽  
Differential Activation ◽  
Interaction Approach ◽  
Relationship Of

Application of the differential activation energy approach suggests that the strong inward opening tendency of the formyl group in 3,4-cyclopropano-7-formyl-bicyclo[4.2.0]octan-1,5-diene and also 3,4-epoxy-7-formyl-bicyclo[4.2.0]octan-1,5-diene is either counter balanced to a level that the reaction turns torquo-neutral or it rotates outward, depending upon the stereo-relationship of the small ring unit with the formyl substituent. The NBO interaction approach, however, predicts inward selectivity throughout. These molecules, therefore, can be used as excellent test examples to judge the validity of one approach over the other.

Thermal rearrangement of functionalized 1,2-divinylcyclopropane systems. A convenient synthesis of substituted 4-cyclohepten-1-ones

1986 ◽  
Vol 64 (1) ◽  
pp. 180-187 ◽  
Author(s):  
Edward Piers ◽  
Max S. Burmeister ◽  
Hans-Ulrich Reissig
Keyword(s):  
Acid Hydrolysis ◽  
The Other ◽  
Thermal Rearrangement ◽  
Enol Ethers ◽  
Acyl Chlorides ◽  
Silyl Ethers ◽  
Convenient Synthesis ◽  
Enol Silyl Ethers ◽  
Hydrolysis Of ◽  
Subsequent Acid

Reaction of the acyl chlorides 14–21 with lithium (phenylthio)(cis-2-vinylcyclopropyl)cuprate (2) provided the ketones 22–29. Compounds 22–25, upon treatment with i-Pr2NLi-Me3SiCl, were converted cleanly into the enol silyl ethers 30–33, which gave the 1,4-cycloheptadienes 34–37 upon thermolysis (100–110 °C). Acid hydrolysis of the latter materials produced the corresponding 4-cyclohepten-1-ones 38–41. However, subjection of the cis-2-vinylcyclopropyl ketones 26–29 to i-Pr2NLi-t-BuMe2SiCl afforded, in each case, a mixture of isomeric enol ethers (26 → 42 + 44 (1:1); 27 → 43 + 45 (1:9); 28 → 56 + 58 (1:1); 29 → 57 + 59 (4:1)). Thermolysis (150–175 °C) of these mixtures, followed by acid hydrolysis of the resultant products, gave the 4-cyclohepten-1-ones 54, 55, 64, and 65, admixed with the corresponding 3-methylenecyclopentenes 52, 53, 62, and 63. On the other hand, treatment of the trans-2-vinylcyclopropyl ketones 70–74 with i-Pr2NLi–t-BuMe2SiCl provided exclusively or predominantly the enol ethers 75–79. Thermolysis (230 °C) of the latter materials and subsequent acid hydrolysis of the resultant products 80, 50, 51, 60, and 61 afforded the 4-cyclopenten-1-ones 38, 54, 55, 64, and 65.

scholarly journals Crystal structure of (E)-4-ethyl-2-(4-methoxybenzylidene)-3,4-dihydronaphthalen-1(2H)-one

2015 ◽  
Vol 71 (6) ◽  
pp. o432-o432
Author(s):  
Mohamed Akhazzane ◽  
Ghali Al Houari ◽  
Mohamed El Yazidi ◽  
Mohamed Saadi ◽  
Lahcen El Ammari
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Dihedral Angle ◽  
Title Compound ◽  
The Other ◽  
Axial Orientation ◽  
Boat Conformation ◽  
Compound C ◽  
Benzene Rings ◽  
Van Der Waals Contacts

In the title compound, C20H20O2, the exocyclic C=C double bond has anEconformation. The ethyl substituent on the cyclohexanone ring is in an axial orientation. The cyclohexanone ring adopts a screw-boat conformation, with the methylene C atom and the C atom bearing the 4-methoxybenzylidene group displaced from the other atoms by 0.812 (1) and 0.334 (1) Å, respectively. The dihedral angle between the planes of the benzene rings is 42.20 (8)°. In the crystal, no directional interactions beyond van der Waals contacts are observed.

scholarly journals Tetrakis(μ-2-iodobenzoato-κ2O:O′)bis[aquacopper(II)]

2012 ◽  
Vol 68 (4) ◽  
pp. m409-m410 ◽  
Author(s):  
Ömür Aydın ◽  
Nagihan Çaylak Delibaş ◽  
Hacali Necefoğlu ◽  
Tuncer Hökelek
Keyword(s):  
Water Molecule ◽  
Benzene Ring ◽  
Dihedral Angle ◽  
Title Complex ◽  
The Other ◽  
Carboxylate Group ◽  
Two Dimensional ◽  
Dimensional Network ◽  
Square Planar ◽  
Benzene Rings

In the centrosymmetric binuclear title complex, [Cu2(C7H4IO2)4(H2O)2], the two CuIIions [Cu...Cu = 2.6009 (5) Å] are bridged by four 2-iodobenzoate (IB) ligands. The four nearest O atoms around each CuIIion form a distorted square-planar arrangement, the distorted square-pyramidal coordination being completed by the O atom of the water molecule at a distance of 2.1525 (16) Å. The dihedral angle between the benzene ring and the carboxylate group is 25.67 (13)° in one of the independent IB ligands and 6.44 (11)° in the other. The benzene rings of the two independent IB ligands are oriented at a dihedral angle of 86.61 (7)°. In the crystal, O—H...O interactions link the molecules into a two-dimensional network. π–π contacts between the benzene rings [centroid–centroid distances = 3.810 (2) and 3.838 (2) Å] may further stabilize the structure.

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