Neutral Guest Capture via Lewis Acid/Base Molecular Square Receptors. X-ray Crystal Structure of {Cyclobis[(cis-(dppp)Pt(4-ethynylpyridyl)2)(cis- (PEt3)2Pt)]Ag2}+6(phenazine)- (-OSO2CF3)6

1998 ◽  
Vol 37 (21) ◽  
pp. 5595-5601 ◽  
Author(s):  
Jeffery A. Whiteford ◽  
Peter J. Stang ◽  
Songping D. Huang
Keyword(s):  
Crystal Structure ◽  
Lewis Acid ◽  
Acid Base ◽  
X Ray ◽  
Molecular Square

An Intramolecular Boron Nitrogen Lewis Acid Base Pair on a Rigid Naphthyl Backbone

2012 ◽  
Vol 67 (6) ◽  
pp. 589-593 ◽  
Author(s):  
Daniel Winkelhaus ◽  
Beate Neumann ◽  
Norbert W. Mitzel
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Lewis Acid ◽  
Elemental Analysis ◽  
Base Pair ◽  
Ring System ◽  
X Ray Diffraction ◽  
Acid Base ◽  
X Ray ◽  
Boron Nitrogen

The reaction of (C6F5)2BCl with 8-lithio-N,N-dimethyl-1-naphthylamine (1) afforded the fivemembered ring system 8-bis(pentafluorophenyl)boryl-N,N-dimethyl-1-naphthylamine (2) with an intramolecular dative B-N bond. The compound was characterised by elemental analysis, NMR spectroscopy and single-crystal X-ray diffraction.

scholarly journals First Total Synthesis and Investigation of the X-ray Crystal Structure of the Pyrano[3,2-a]carbazole Alkaloid Clausenalansine A

Synthesis ◽  
2020 ◽  
Vol 53 (02) ◽  
pp. 359-364
Author(s):  
Hans-Joachim Knölker ◽  
Valerie Lösle ◽  
Olga Kataeva
Keyword(s):  
Crystal Structure ◽  
Total Synthesis ◽  
Lewis Acid ◽  
Oxidative Cyclization ◽  
Formyl Group ◽  
Pyran Ring ◽  
X Ray ◽  
Synthetic Strategy

AbstractWe describe the first total synthesis of the recently discovered pyrano[3,2-a]carbazole alkaloid clausenalansine A. The synthetic strategy for the construction of this formylpyrano[3,2-a]carbazole is based on a sequence of Buchwald–Hartwig coupling, palladium(II)-catalyzed oxidative cyclization, Lewis acid promoted annulation of the pyran ring, and chemoselective oxidation of a methyl to a formyl group.

Lewis-Säure/Base Addukte von TiCl4 und Methylpyridinen / Lewis Acid/Base Adducts of TiCl4 and Methylpyridines

2000 ◽  
Vol 55 (9) ◽  
pp. 877-881 ◽  
Author(s):  
Karl Hensen ◽  
Alexander Lemke ◽  
Michael Bolte
Keyword(s):  
Molecular Structure ◽  
Lewis Acid ◽  
Equatorial Position ◽  
Acid Base ◽  
Nitrogen Base ◽  
X Ray ◽  
Nitrogen Bases ◽  
Distorted Trigonal Bipyramid ◽  
In Trans ◽  
Ray Methods

By the reaction of 2-methyl- and 2,6-dimethylpyridine the first neutral TiCl4L complexes (L = single bonded ligand) could be synthesized. The structures have been determined by single crystal X-ray methods. The best description of the molecular structure is a distorted trigonal bipyramid with the nitrogen base occupying an equatorial position. With 2,4-dimethylpyridine, a 1:2 adduct is formed, where the nitrogen bases are in trans-positions of a TiCl4N2-octahedron, as also confirmed by an X-ray analysis

Studies via X-ray analysis on intermolecular interactions and energy frameworks based on the effects of substituents of three 4-aryl-2-methyl-1H-imidazoles of different electronic nature and their in vitro antifungal evaluation

2018 ◽  
Vol 74 (11) ◽  
pp. 1447-1458 ◽  
Author(s):  
Mario A. Macías ◽  
Nerith-Rocio Elejalde ◽  
Estefanía Butassi ◽  
Susana Zacchino ◽  
Jaime Portilla
Keyword(s):  
Crystal Structure ◽  
Antifungal Activity ◽  
Crystal Structures ◽  
Intermolecular Interactions ◽  
Acid Base ◽  
Electronic Nature ◽  
Aryl Ring ◽  
X Ray ◽  
Base Properties

The crystal structures of 2-methyl-4-phenyl-1H-imidazole, C10H10N2, (3a), 4-(4-chlorophenyl)-2-methyl-1H-imidazole hemihydrate, C10H9ClN2·0.5H2O, (3b), and 4-(4-methoxyphenyl)-2-methyl-1H-imidazole, C11H12N2O, (3c), have been analyzed. It was found that the electron-donating/withdrawing tendency of the substituent groups in the aryl ring influence the acid–base properties of the 2-methylimidazole nucleus, changing the strength of the intermolecular N—H...N interactions. This behaviour not only influences the crystal structure but also seems to have an important effect on the antifungal activity. Considering the substituent groups, that is, H in (3a), Cl in (3b) and OMe in (3c), the formation of strong N—H...N connections has the probability (3a) > (3b) > (3c), while compound (3c) proves to be more active than (3a) and (3b) at all concentrations against C. neoformans.

The Methylene-bridged Dialuminium Compound R2Al-CH2-AlR2 [R=CH(SiMe3)2] as an Effective Chelating Lewis Acid – Adducts with Halides, Perchlorate and Isopropylamide

2012 ◽  
Vol 67 (10) ◽  
pp. 1081-1090 ◽  
Author(s):  
Werner Uhl ◽  
Christian Rösener ◽  
Christina Stefaniak ◽  
Tim Choy ◽  
Beate Jasper-Peter ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Organic Solvents ◽  
Lewis Acid ◽  
Stoichiometric Ratio ◽  
Acid Base ◽  
X Ray ◽  
X Ray Crystallography ◽  
Coordination Behaviour ◽  
Lewis Acid Adducts ◽  
Oxygen Atoms

The new methylene-bridged dialuminium compound Aryl2Al-CH2-AlAryl2 1b was synthesised from Cl2Al-CH2-AlCl2 and four equivalents of LiAryl [Aryl=C6H2(2,4,6-i-Pr)3]. A 1 : 2 stoichiometric ratio of the starting compounds afforded the dimeric aluminium halide (Aryl2AlCl)2 (2) by dismutation. The coordination behaviour of the related, but more easily available dialuminium compound R2Al-CH2-AlR2 [R=CH(SiMe3)2] 1a was explored. It yields the Lewis acid base adducts [M][R2Al-CH2-AlR2(μ-X)] [3a, M=Li(TMEN)2, X=Cl; 3b, M=Li(TMEN)2, X=Br; 3c, M=K(18-crown-6), X=ClO4; 3d, M=Li(TMEN)2, X=NH(i-Pr)] with X residing in a bridging position between the two Al atoms as evident from NMR spectroscopy and X-ray crystallography (3b, 3c, 3d). Compound 3c is a unique example of a stable, in organic solvents soluble adduct that features a ClO4- anion coordinated by an alkylaluminium compound via two of its oxygen atoms.

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