scholarly journals Synthesis of 2,24-Diene-12,13,15,16,34,35,37,38-octaphenyl[4.4]triphenylparacyclophane

Synthesis ◽  
2021 ◽  
Author(s):  
Duy H. Hua ◽  
Bernard Wiredu ◽  
Mahendra Thapa ◽  
Sheen Y. Hua ◽  
John Desper
Keyword(s):  
Olefin Metathesis ◽  
Knoevenagel Condensation ◽  
Coupling Reaction ◽  
Diels Alder ◽  
Synthetic Methodology ◽  
X Ray ◽  
X Ray Crystallography ◽  
Vinyl Group ◽  
Synthetic Intermediate

AbstractA new octaphenyl[4.4]triphenylparacyclophanediene was readily synthesized in six steps from p-xylene via the installment of bromine atoms, replacement with a vinyl group, carbonylative coupling, intermolecular followed by intramolecular double Grubbs olefin metathesis, Knoevenagel condensation, and Diels–Alder cycloaddition. The belt-shaped structure and trans-stereochemistry of the alkene moieties of the octaphenyl[4.4]triphenylparacyclophane and a synthetic intermediate, 2,21-dioxo-11,30-diene[3.4.3.4]paracyclophane, were determined by X-ray crystallography. The synthetic methodology leading to octaphenyl[4.4]triphenylparacyclophane is applicable for the synthesis of substituted triphenylparacyclophanes and possibly their corresponding bis-hexabenzocoronenylparacyclophanes via a Scholl–Mullen oxidative aryl-aryl coupling reaction.

scholarly journals Synthesis of the [11]Cyclacene Framework by Repetitive Diels–Alder Cycloadditions

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 3047
Author(s):  
John B. Bauer ◽  
Fatima Diab ◽  
Cäcilia Maichle-Mössmer ◽  
Hartmut Schubert ◽  
Holger F. Bettinger
Keyword(s):  
Building Block ◽  
Building Blocks ◽  
Alder Reaction ◽  
Diels Alder ◽  
X Ray ◽  
X Ray Crystallography ◽  
Diels Alder Reaction ◽  
Synthetic Intermediate

The Diels–Alder cycloaddition between bisdienes and bisdienophile incorporating the 7-oxa-bicyclo[2.2.1]heptane unit are well known to show high diastereoselectivity that can be exploited for the synthesis of molecular belts. The related bisdiene 5,6,7,8-tetramethylidene-2-bicyclo[2.2.2]octene is a valuable building block for the synthesis of photoprecursors for acenes, but it has not been employed for the synthesis of molecular belts. The present work investigates by computational means the Diels–Alder reaction between these bisdiene building blocks with syn-1,4,5,8-tetrahydro-1,4:5,8-diepoxyanthracene, which shows that the diastereoselectivity of the Diels–Alder reaction of the etheno-bridged bisdiene is lower than that of the epoxy-bridged bisdiene. The reaction of the etheno-bridged bisdiene and syn-1,4,5,8-tetrahydro-1,4:5,8-diepoxyanthracene in 2:1 ratio yields two diastereomers that differ in the orientation of the oxa and etheno bridges based on NMR and X-ray crystallography. The all-syn diastereomer can be transformed into a molecular belt by inter- and intramolecular Diels–Alder reactions with a bifunctional building block. The molecular belt could function as a synthetic intermediate en route to a [11]cyclacene photoprecursor.

New pseudohalide ligands in Ru-catalyzed olefin metathesis — A robust, air-activated iminopyrrolato catalyst

2005 ◽  
Vol 83 (6-7) ◽  
pp. 748-754 ◽  
Author(s):  
Samantha D Drouin ◽  
Heather M Foucault ◽  
Glenn PA Yap ◽  
Deryn E Fogg
Keyword(s):  
Key Words ◽  
Olefin Metathesis ◽  
High Reactivity ◽  
Ring Closing Metathesis ◽  
Grubbs Catalyst ◽  
X Ray ◽  
X Ray Crystallography

Reaction of the Grubbs catalyst RuCl2(PCy3)2(CHPh) (1) with lithium 2-[(2,6-diisopropylphenyl)imino]pyrrolide·Et2O (LiNN′·Et2O) gives alkylidene complex 5, containing a chelating, σ-bound iminopyrrolato unit. The structure of 5 is confirmed by X-ray crystallography. Treatment of 5 with pyridine generates RuCl(NN′)(py)2(CHPh) (6) via displacement of PCy3. Complex 5 effects ring-closing metathesis in air, displaying high reactivity relative to 6.Key words: ruthenium, alkylidene, metathesis, pyrrolimine, iminopyrrolato.

scholarly journals Synthesis and characterization of a new bis-NHC palladium complex and its catalytic activity in the Mizoroki–Heck reaction

2020 ◽  
Vol 44 (11-12) ◽  
pp. 684-688
Author(s):  
Can Feng ◽  
Cheng-xin Liu ◽  
Yu-fang Wang ◽  
Jin Cui ◽  
Ming-jie Zhang
Keyword(s):  
Palladium Complex ◽  
Coupling Reaction ◽  
Aryl Halides ◽  
Heck Coupling ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Excellent Stability ◽  
C Nmr

A new bis- N-heterocyclic carbene palladium complex, (C13H9N2F2)2PdCl2, is synthesized by a three-step reaction and characterized by 1H NMR and 13C NMR spectroscopy as well as by X-ray crystallography. This new bis- N-heterocyclic carbene palladium complex has excellent stability and is capable of efficiently catalyzing the Mizoroki–Heck coupling reaction of aryl halides with acrylates.

Oxidative coupling of cycloalkanones with 3-(pyridin-2-yl)-1,2,4-triazinone coordinated to Pd(II)

2018 ◽  
Vol 73 (8) ◽  
pp. 583-587
Author(s):  
Mustafa M. El-Abadelah ◽  
Firas F. Awwadi ◽  
Hamdallah A. Hodali ◽  
Rasha S. Rawajfeh ◽  
Monther S. Zreid ◽  
...  
Keyword(s):  
Single Crystal ◽  
Spectral Data ◽  
Oxidative Coupling ◽  
Coupling Reaction ◽  
X Ray ◽  
X Ray Crystallography ◽  
Square Planar ◽  
Pd Complexes ◽  
Palladium Ion

AbstractDichloro[3-(pyridin-2-yl)-1,2,4-triazinone]Pd(II) undergoes oxidative C–C coupling reaction with cyclopentanone and cyclohexanone at 110°C to yield the respective Pd complexes, chloro[1-(4-chlorophenyl)-5-(2-hydroxycyclopent-1-enyl)-3-(pyridin-2-yl)-1,2,4-triazin-6(1H)-one]palladium(II) (3) and chloro[1-(4-chlorophenyl)-5-(2-hydroxycyclohex-1-enyl)-3-(pyridin-2-yl)-1,2,4-triazin-6(1H)-one]palladium(II) (4). The structures of both complexes are supported by spectral data and confirmed by single-crystal X-ray crystallography. The molecules 3 and 4 stack to form tunnel structures, whilst the geometry around the palladium ion is square planar.

scholarly journals Synthesis and Fluorescent Properties of Novel Isoquinoline Derivatives

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4070 ◽  
Author(s):  
Łukasz Balewski ◽  
Franciszek Sączewski ◽  
Maria Gdaniec ◽  
Anita Kornicka ◽  
Karolina Cicha ◽  
...  
Keyword(s):  
Optical Properties ◽  
Potassium Carbonate ◽  
Research Work ◽  
Coupling Reaction ◽  
Fluorescent Properties ◽  
X Ray ◽  
X Ray Crystallography ◽  
Ring Compounds ◽  
Type Coupling ◽  
Isoquinoline Derivatives

Isoquinoline derivatives have attracted great interest for their wide biological and fluorescent properties. In the current study, we focused on the synthesis of a series of novel isoquinoline derivatives substituted at position 3 of the heteroaromatic ring. Compounds were obtained in a Goldberg–Ullmann-type coupling reaction with appropriate amides in the presence of copper(I) iodide, N,N-dimethylethylenediamine (DMEDA), and potassium carbonate. The structures of novel isoquinolines were confirmed by IR, NMR, and elemental analysis, as well as X-ray crystallography. In the course of our research work, the visible fluorescence of this class of compounds was observed. The above findings prompted us to investigate the optical properties of the selected compounds.

The Two-step Synthesis and Crystal and Molecular Structure of Tetracyclo[6.4.0.02,11.04,9]dodec-6-ene-3,10-dione

1975 ◽  
Vol 53 (14) ◽  
pp. 2068-2075 ◽  
Author(s):  
Yuen-Mui Ngan ◽  
Steven J. Rettig ◽  
John R. Scheffer ◽  
James Trotter
Keyword(s):  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Membered Ring ◽  
Diels Alder ◽  
High Yield ◽  
Side Chain ◽  
X Ray ◽  
Long Wavelength ◽  
Vinyl Group ◽  
Alder Adduct

The photochemistry of the trans-1,3,5-hexatriene-p-benzoquinone Diels–Alder adduct has been investigated. Irradiation of this material in its long wavelength n → π* absorption band leads to a single photoproduct in high yield. A single crystal X-ray structure determination shows this product to be tetracyclo[6.4.0.02,11.04,9]dodec-6-ene-3,10-dione, the result of a novel regiospecific intramolecular 2 + 2 photoaddition between the side chain vinyl group and the enedione double bond. Crystals of tetracyclo[6.4.0.02,11.04,9]dodec-6-ene-3,10-dione are monoclinic, a = 7.5290(7), b = 19.072(1), c = 6.7237(4) Å, β = 107.918(6) °, Z = 4, space group P21/n. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.041 for 1603 reflections with I ≥ 3σ(I). The structure consists of well-separated molecular units. Bond distances are: C=O, 1.216 and 1.219(2), C=C, 1.318(2), mean C(sp3)—C(sp2), 1.508, mean C(sp3)—C(sp3), 1.560 in the four-membered ring and 1.544 elsewhere, mean C(sp3)—H, 0.99, and mean C(sp2)—H, 0.95 Å. Bond distances between nonhy drogen atoms have been corrected for thermal motion. A possible rationalization for the observed photoprocess is discussed in terms of conformational and radical stability effects.

scholarly journals Ortho-Phenylene-Based Macrocyclic Hydrocarbons Assembled Using Olefin Metathesis

2020 ◽  
Author(s):  
Viraj kirinda ◽  
Briana Schrage ◽  
Christopher Ziegler ◽  
Scott Hartley
Keyword(s):  
Nmr Spectroscopy ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Olefin Metathesis ◽  
Secondary Structures ◽  
Higher Order ◽  
Order Structure ◽  
X Ray ◽  
X Ray Crystallography ◽  
Simple Strategy

While many foldamer systems reliably fold into well-defined secondary structures, higher order structure remains a challenge. A simple strategy for the organization of folded subunits in space is to link them together within a macrocycle. Previous work has shown that o-phenylenes can be co-assembled with rod-shaped linkers into twisted macrocycles, showing an interesting synergy between folding and thermodynamically controlled macrocyclization. In these systems the foldamer units were largely decoupled from each other both conformationally and electronically. Here, we show that hydrocarbon macrocycles, with very short ethenylene linkers, can be assembled from o-phenylenes using olefin metathesis. Characterization by NMR spectroscopy, X-ray crystallography, and ab initio calculations shows that the products are approximately triangular [3+3] macrocycles with helical o-phenylene corners in a heterochiral configuration. Their photophysics are dominated by the 4,4′-diphenylstilbene moieties, the longest conjugated segments, with further conjugation broken by the twisting of the o-phenylenes.

Green Synthetic Methodology of (E)-2-cyano-3-aryl Selective Knoevenagel Adducts Under Microwave Irradiation

2019 ◽  
Vol 6 (1) ◽  
pp. 54-60 ◽  
Author(s):  
David Esteban Quintero Jimenez ◽  
Lucas Lima Zanin ◽  
Luan Farinelli Diniz ◽  
Javier Ellena ◽  
André Luiz Meleiro Porto
Keyword(s):  
Organic Chemistry ◽  
Microwave Irradiation ◽  
Organic Synthesis ◽  
Knoevenagel Condensation ◽  
Green Solvents ◽  
Nacl Solution ◽  
Synthetic Methodology ◽  
X Ray ◽  
Basic Catalysts ◽  
High Yields

Background: The Knoevenagel condensation is an important reaction in organic chemistry because of its capacity to form new C-C bonds and its products are mainly used in organic synthesis as intermediates, due to the large number of reactions they can undergo. Based on the importance of the Knoevenagel adducts, a sustainable synthetic methodology was developed employing microwave irradiation. Objective: Develop a synthetic methodology employing microwave irradiation and green solvents to obtain Knoevenagel adducts with high yields. Methods: Knoevenagel condensation reactions were evaluated with different basic catalysts, as well as in the presence or absence of microwave irradiation. The scope of the reaction was expanded using different aldehydes, cyanoacetamide or methyl cyanoacetate. The geometry of the formed products was also evaluated. Results: After the optimization process, the reactions between aldehydes and cyanoacetamide were performed with triethylamine as catalyst, in the presence of microwave irradiation, in 35 minutes, using NaCl solution as solvent and resulted in high yields 90-99%. The reactions performed between aldehydes and methyl cyanoacetate were also performed under these conditions, but showed better yields with EtOH as solvent 70-90%. Finally, from X-ray analysis, the (E)-geometry of these compounds was confirmed. Conclusion: In this study we developed synthetic methodology of Knoevenagel condensation using triethylamine, green solvents and microwave irradiation. In 35 minutes, products with high yields (70- 99%) were obtained and the (E)-geometry of the adducts was confirmed.

Nickel-Catalysed Synthesis of 17-Arylandrosta-5,16-Dienes

2017 ◽  
Vol 41 (11) ◽  
pp. 653-656
Author(s):  
Lizhong Wang ◽  
Ting Wang ◽  
Chenlu Dai ◽  
Yang Li ◽  
Cunde Wang
Keyword(s):  
Coupling Reaction ◽  
X Ray ◽  
Arylboronic Acids ◽  
X Ray Crystallography

An efficient Ni-catalysed coupling reaction between arylboronic acids and 17-trifluoromethanesulfonyl- 3β-acetoxyandrosta-5,16-diene which was obtained by the sulfonylation of 3β-acetoxylandrost-5-ene-17-one was developed to afford 17-aryl- 3β-acetoxy-androsta-5,16-dienes in moderate to good yields (52–85%). The structure of the 3,4-dimethoxyaryl product was confirmed by X-ray crystallography.

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