scholarly journals Synthesis and highly efficient light-induced rearrangements of diphenylmethylene(2-benzo[b]thienyl)fulgides and fulgimides

2020 ◽  
Vol 16 ◽  
pp. 1820-1829
Author(s):  
Vladimir P Rybalkin ◽  
Sofiya Yu Zmeeva ◽  
Lidiya L Popova ◽  
Valerii V Tkachev ◽  
Andrey N Utenyshev ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Uv Irradiation ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Highly Efficient ◽  
Shift Reaction ◽  
Photoinduced Rearrangement ◽  
C Nmr

2-Benzo[b]thienyl fulgides and fulgimides containing bulky diphenylmethylene substituents were synthesized in the form of their ring-opened E- or Z-isomers. In contrast to the majority of known fulgides/fulgimides, that form colored ring-closed structures under UV irradiation, the obtained compounds undergo an irreversible transformation leading to decoloration of their solutions. This rearrangement with the formation of the dihydronaphthalene core appeared to be by 2–3 orders of magnitude more efficient than for the known diphenylmethylene(aryl(hetaryl))fulgides. The molecular structures of E- and Z-isomers and of products of the photoinduced rearrangement completed by 1,5-H shift reaction, 3a,4-dihydronaphtho[2,3-c]furans(pyrroles) C, were established based on the data of 1H and 13C NMR spectroscopy and X-ray diffraction studies.

An unusual reaction of a bridged triterpenoid α-diketone with acetic anhydride

1991 ◽  
Vol 56 (12) ◽  
pp. 2917-2935 ◽  
Author(s):  
Eva Klinotová ◽  
Václav Křeček ◽  
Jiří Klinot ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
Spectral Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Condensation Products ◽  
Unsaturated Lactones ◽  
C Nmr

3β-Acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) reacts with acetic anhydride in pyridine under very mild conditions affording β-lactone IVa and γ-lactones Va and VIIa as condensation products. On reaction with pyridine, lactones Va and VIIa undergo elimination of acetic acid to give unsaturated lactones VIIIa and IXa, respectively. Similarly, the condensation of 20β,28-epoxy-21,22-dioxo-18α,19βH-ursan-3β-yl acetate (IIIb) with acetic anhydride leads to β-lactone IVb and γ-lactone Vb; the latter on heating with pyridine affords unsaturated lactone VIIIb and 21-methylene-22-ketone Xb. The structure of the obtained compounds was derived using spectral methods, particularly 1H and 13C NMR spectroscopy; structure of lactone IVa was confirmed by X-ray diffraction.

β-Hydroxydithiozimtsäurederivate als Liganden. Synthese und Charakterisierung neuartiger 1,1-Ethendithiolato- und O,S-Chelatkomplexe / Derivatives of β -Hydroxydithiocinnamic Acids as Ligands. Syntheses and Characterisation of Novel 1,1-Ethenedithiolato and O,S-Chelate Complexes

2007 ◽  
Vol 62 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Karsten Schubert ◽  
Helmar Görls ◽  
Wolfgang Weigand
Keyword(s):  
Bidentate Ligand ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Chelate Complexes ◽  
X Ray ◽  
H Nmr ◽  
Hexyl Ester ◽  
Elemental Analyses ◽  
Derivatives Of ◽  
C Nmr

Starting from 4-bromoacetophenone 1, the 4-bromo-β -hydroxydithiocinnamic acid 2 and the 4-bromo-β -hydroxydithiocinnamic acid hexyl ester 3 were prepared using carbon disulfide and potassium-tert-butylate as a base. Acting as a ligand, the acid gives 1,1-ethenedithiolato complexes with (Ph3P)2Pt(II) (4a), (Et3P)2Pt(II) (4b), dppePt(II) (4c), (Ph3P)2Pd(II) (4d), dppePd(II) (4e), and dppeNi(II) (4f). In contrast to the acid, the deprotonated ester 3 forms a monoanionic bidentate ligand. [O,S] Complexes of Pt(II) (5a), Pd(II) (5b) and Ni(II) (5c) were obtained. All complexes have been fully characterised using 1H NMR, 13C NMR and 31P NMR spectroscopy, mass spectrometry, infrared spectroscopy and elemental analyses. The molecular structures of the complexes 4b and 5a - 5c were determined by X-ray diffraction analyses.

Synthesis and structural characterization of substituted phenols with a m-terphenyl backbone 2,4,6-R3C6H2OH (R=2,4,6-Me3C6H2, Me5C6)

2015 ◽  
Vol 70 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Atena B. Şolea ◽  
Marian Olaru ◽  
Cristian Silvestru ◽  
Ciprian I. Raţ
Keyword(s):  
Grignard Reagent ◽  
Cross Coupling ◽  
Molecular Structures ◽  
Coupling Reactions ◽  
X Ray Diffraction ◽  
Substituted Phenols ◽  
X Ray ◽  
Cross Coupling Reactions ◽  
C Nmr

AbstractSubstituted phenols with a m-terphenyl backbone 2,4,6-R3C6H2OH [R=2,4,6-Me3C6H2 (1), Me5C6 (2)] were synthesized using Kumada cross-coupling reactions between 2,4,6-I3C6H2OH and the corresponding Grignard reagent. Both compounds were structurally characterized in solution by 1H and 13C NMR spectroscopy and HRMS. The molecular structures of 1 and 2 were determined by single-crystal X-ray diffraction.

scholarly journals Alkylation and 1,3-Dipolar Cycloaddition of 6-Styryl-4,5-dihydro-2H-pyridazin-3-one: Synthesis of NovelN-Substituted Pyridazinones and Triazolo[4,3-b]pyridazinones

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Souad Mojahidi ◽  
Hanan Sekkak ◽  
El Mostapha Rakib ◽  
Maria G. P. M. S. Neves ◽  
Maria A. F. Faustino ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Dipolar Cycloaddition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nitrile Imines ◽  
C Nmr

Some newN-substituted pyridazinones and triazolo[4,3-b]pyridazinones were synthesized, respectively, by simple alkylation and 1,3-dipolar cycloaddition of pyridazin-3-one with nitrile imines. The regioselectivity of the reactions was ascertained by1H,13C NMR spectroscopy and X-ray diffraction of the synthesized compounds.

Tetra(alkynyl)silanes, a 3,6-Disila-triyne, a 3,6,9-Trisila-tetrayne, a 1,3,4,6-Tetrasiladiyne, and Bis(trimethylstannyl)ethyne. Molecular Structures and Solid-state NMR Studies

2010 ◽  
Vol 65 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Ezzat Khan ◽  
Amin Badshah ◽  
Elias Molla ◽  
Peter Thoma ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Mas Nmr ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Nmr Studies ◽  
X Ray ◽  
Solution State ◽  
Nmr Data

The molecular structures of three alkynylsilanes, tetrakis(ethynyl-p-tolyl)silane, 3,3,6,6,-tetramethyl- 3,6-disila-triyne, 3,3,6,6,9,9,-hexamethyl-3,6,9-trisila-tetrayne, and of bis(trimethylstannyl)- ethyne have been determined by X-ray diffraction. The same alkynylsilanes, and in addition 1,2- bis(trimethylsilylethynyl)-1,1,2,2-tetramethyldisliane, were studied by solid-state 13C and 29Si MAS NMR spectroscopy. The results of these measurements were compared with crystallographic evidence and also with relevant solution-state NMR data.

The structures of indoiyl(alkoxy)carbenium tetrafluoroborates: a new class of highly stabilized carbenium ions

1989 ◽  
Vol 44 (6) ◽  
pp. 659-665 ◽  
Author(s):  
Ulf Pindur ◽  
Ludwig Pfeuffer ◽  
Camran Flo ◽  
Werner Massa ◽  
Karin Seitz
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Crystalline State ◽  
X Ray Diffraction ◽  
Carbenium Ions ◽  
X Ray ◽  
Axial Chirality ◽  
New Class ◽  
Charge Distributions ◽  
C Nmr

The conformations of and charge distributions in indolyl(alkoxy)carbenium tetrafluoroborates 2, a new class of highly stabilized carbenium ions, were investigated by 1H and 13C NMR spectroscopy and the crystal structure of indol-3-yl(methoxy)phenylcarbenium tetrafluoroborate (2e) was determined by X-ray diffraction methods. The phenyl-substituted cation of 2e exhibits axial chirality in the crystalline state

scholarly journals Synthesis, Characterization, and Catalytic Application of Palladium Complexes Containing Indolyl-NNN-Type Ligands

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4426
Author(s):  
Pang-Chia Lo ◽  
Chun-Wei Yang ◽  
Wen-Kai Wu ◽  
Chi-Tien Chen
Keyword(s):  
Nmr Spectroscopy ◽  
Aryl Halide ◽  
Suzuki Reaction ◽  
Palladium Complexes ◽  
Molecular Structures ◽  
Palladium Acetate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Application ◽  
Ligand Precursors

In this study, a series of N-heterocyclic indolyl ligand precursors 2-Py-Py-IndH, 2-Py-Pz-IndH, 2-Py-7-Py-IndH, 2-Py-7-Pz-IndH, and 2-Ox-7-Py-IndH (L1H-L5H) were prepared. The treatment of ligand precursors with 1 equivalent of palladium acetate affords palladium complexes 1–5. All ligand precursors and palladium complexes were characterized by NMR spectroscopy and elemental analysis. The molecular structures of complexes 3 and 5 were determined by single crystal X-ray diffraction techniques. The application of those palladium complexes 1–5 to the Suzuki reaction with aryl halide substrates was examined.

scholarly journals Crystal structure of 2-(2,6-diisopropylphenyl)-N,N-diethyl-3,3-dimethyl-2-azaspiro[4.5]decan-1-amine: a diethylamine adduct of a cyclic(alkyl)(amino)carbene (CAAC)

2021 ◽  
Vol 77 (9) ◽  
Author(s):  
Roxanne A. Naumann ◽  
Joseph W. Ziller ◽  
Allegra L. Liberman-Martin
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Title Compound ◽  
Lithium Diisopropylamide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compound C ◽  
Lithium Diethylamide ◽  
C Nmr

The structure of the title compound, C27H46N2, at 93 K has monoclinic (P21/n) symmetry. The title compound was prepared by treatment of 2-(2,6-diisopropylbenzene)-3,3-dimethyl-2-azaspiro[4.5]dec-1-en-2-ium hydrogen dichloride with two equivalents of lithium diethylamide. Characterization of the title compound by single-crystal X-ray diffraction and 1H and 13C NMR spectroscopy is presented. Formation of the diethylamine adduct of the cyclic(alkyl)(amino)carbene (CAAC) was unexpected, as deprotonation using lithium diisopropylamide results in free CAAC formation.

Partial Reduction of the N–O Functions of Partially Deprotonated Bis(hydroxylamine) Complexes

2009 ◽  
Vol 64 (10) ◽  
pp. 1208-1212
Author(s):  
Patrick Bösing ◽  
Hans-Georg Stammler ◽  
Norbert W. Mitzel
Keyword(s):  
Nmr Spectroscopy ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Elemental Analysis ◽  
Titanium Tetrachloride ◽  
Partial Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amine Function ◽  
C Nmr

The reduction of a partially deprotonated bishydroxylamine complex {(tBu2Ga)2[cyclo-ON(Me)(CH2)2- (Me)NO][HON(Me)(CH2)2(Me)(H)NO]} with a reagent composed of titanium tetrachloride and methyllithium leads to the reduction of one of the N-O groups to an amine function affording the salt {(tBu2Ga)[cyclo- ON(H)(Me)(CH2)2NHMe]}+ {tBu2GaCl2}−. This has been characterised by 1H and 13C NMR spectroscopy, by elemental analysis and by single crystal X-ray diffraction, showing the neutral amine/hydroxylamine ligand to be present in its tautomeric aminoxide form. The molecules form hexameric cyclic aggregates by N-H···Cl hydrogen bonds.

Phenyl-Induced 3,1,11-Rearrangement in the Synthesis of Mixed Pyrrolyl/Dicarbollide Cobaltadicarbaboranes

1997 ◽  
Vol 62 (8) ◽  
pp. 1263-1272 ◽  
Author(s):  
Josep Bertran ◽  
Clara Viñas ◽  
Sílvia Gomez ◽  
Mouad Lamrani ◽  
Francesc Teixidor ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Diffraction Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phenyl Rings ◽  
C Nmr

Mixed pyrrolide cobaltadicarbollides have been prepared from the reaction involving potassium pyrrolide, anhydrous CoCl2 and the [7,8-(C6H5)2-nido-7,8-C2B9H10]- anion in dimethoxyethane. An alternative and higher-yield route consists in the reaction between 1,2-(C6H5)2-closo-1,2-C2B10H10 and potassium pyrrolide in the presence of anhydrous CoCl2. As confirmed by the X-ray diffraction analysis of [3-(η5-NC4H4)-1,11-(C6H5)2-closo-3,1,11-CoC2B9H9], the phenyl rings were found to enhance the rearrangement of the metallacarborane cluster carbons to produce the 3,1,11-isomer instead of the expected 3,1,2-derivative. As suggested by 1H and 13C NMR spectroscopy, the electron-withdrawing properties and steric requirements of the phenyl rings facilitate the rearrangement.

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