Search results for "Halogen"

2017

The title compound, C12H14Br2, was prepared by bromination/dehydrobromination ofE,E,Z-cyclododecatriene. The crystal is composed ofC2-symmetrical molecules with anEconformation of the bromoalkene fragments and nearly linear alkyne units. The torsion angles in the ring suggest significant ring strain.

Studies of Nature of Uncommon Bifurcated I–I···(I–M) Metal-Involving Noncovalent Interaction in Palladium(II) and Platinum(II) Isocyanide Cocrystals

2021

Two isostructural trans-[MI2(CNXyl)2]·I2 (M = Pd or Pt; CNXyl = 2,6-dimethylphenyl isocyanide) metallopolymeric cocrystals containing uncommon bifurcated iodine···(metal–iodide) contact were obtained. In addition to classical halogen bonding, single-crystal X-ray diffraction analysis revealed a rare type of metal-involved stabilizing contact in both cocrystals. The nature of the noncovalent contact was studied computationally (via DFT, electrostatic surface potential, electron localization function, quantum theory of atoms in molecules, and noncovalent interactions plot methods). Studies confirmed that the I···I halogen bond is the strongest noncovalent interaction in the systems, followed …

Identification of the Iodination and Bromination Products of 3-Hydroxybenzaldehyde: Preparation of 5-Hydroxy-2-iodobenzaldehyde

2017

The monohalogenation products of 3-hydroxybenzaldehyde (1) are useful synthons for the preparation of more complex molecules.1–4 For example, the introduction of a halogen allows the use of a Suzuk...

Der nachweis der kettenstruktur von aus p-kresol und formaldehyd aufgebauten mehrkernverbindungen. I. Durch verschiedene synthese und identifizierung…

1962

In ubersichtlicher, mehrfacher Synthese werden homologe Mehrkernverbindungen aufgebaut, die aus uber Methylenbrucken verbundenen p-Kresolbausteinen bestehen (Novolak-Struktur). Die verschiedenen, zu einer Mehrkernverbindung fuhrenden Synthesen geben identische Verbindungen. Die Kettenstruktur dieser Mehrkernverbindungen kann durch kettenanaloge Enthalogenierungen, durch geeignete Kondensationen (Gl. (1)) sowie durch entsprechende Substitutionsbanden in den IR-Spektren der Verbindungen nachgewiesen werden. By means of rational, multiple syntheses, homologous polynuclear compounds were prepared, consisting of p-cresol units linked by methylene bridges (Novolac structure). The different ways o…

ChemInform Abstract: One-Pot Synthesis of Pyrrole-2-carboxylates and -carboxamides via an Electrocyclization/Oxidation Sequence.

2015

An electrocyclic ring closure is the key step of an efficient one-pot method for the synthesis of pyrrole-2-carboxylates and -carboxamides from chalcones and glycine esters or amides. The 3,4-dihydro-2H-pyrrole intermediates generated in situ are oxidized to the corresponding pyrroles by stoichiometric oxidants or by catalytic copper(II) and air in moderate to high yields. A wide range of functional groups are tolerated, and further combination with an in situ bromination gives access to polyfunctional pyrrole scaffolds.

Hierarchical halogen bonding induces polymorphism

2009

Co-crystals of 1-iodo-3,5-dinitrobenzene and 1,4-diazabicyclo[2.2.2]octane manifest either two strong or one strong and one weak intermolecular 2 : 1 halogen bond (XB) motifs in polymorphic structures I and II, respectively, whereas weaker XB-donor 4,4-bipyridine just forms 1 : 1 structure III with one strong halogen bond.

Fluorinated Pyrazoles and Indazoles

2014

The synthesis of fluorine containing pyrazoles has been boosted in the past decades due to the interesting properties that confer these building blocks in pharmaceutical and agricultural active ingredients. There are two main methods for the synthesis of fluorine-containing organic compounds, namely, the direct replacement of an atom or functional group such as diazo, hydroxyl, halogen or hydrogen by fluorine, and the modification of fluorine-containing building blocks. In the case of fluorinated pyrazoles the latter approach is the most commonly applied. This chapter deals primarily with the pivotal procedures that allow the preparation of fluoro- and fluoroalkyl- pyrazoles. Their benzocon…

ChemInform Abstract: Iodocyclization of o-Alkynylbenzamides Revisited: Formation of Isobenzofuran-1(3H)-imines and 1H-Isochromen-1-imines Instead of …

2013

Remarkably, isobenzofuran and benzopyran derivatives are obtained by the title reaction and not as described in earlier publications five- or six-membered lactams.

Challenges in the Electrochemical Synthesis of Si 2 Cl 6 Starting from Tetrachlorosilane and Trichlorosilane

2022

Polymere ester von Säuren des phosphors, 5. Ringöffnende polymerisation des 2-phenoxy-1,3,2-dioxaphospholan durch Michaelis-Arbuzov-reaktion

1977

2-Phenoxy-1,3,2-dioxaphospholane (14) was polymerized by benzyl halogenides at temperatures between 120 and 200°C. It was found that the main chain consists predominantly of unexpected ethylene 1,2-ethanediphosphonate units 7; only about 10% of the monomer was incorporated as the expected 2-hydroxyethanephosphonate structure. An insertion mechanism, proposed by Harwood and Patel for the analogous polymerization of 2-phenyl-1,3,2-dioxaphospholane, does not agree with our experimental results. A hypothesis is developed involving a two step addition process, which exclusively occurs at the chain end. Alternating, one monomer molecule is added by a normal Michaelis-Arbuzov-reaction, and then a …