Polycyclic rearrangements: novel Lewis acid-catalysed rearrangement of the pentacyclo[5.4.0.02,6.03,10.05,9]undecane framework; X-ray crystal structure of 1,10-dimethylpentacyclo[5.4.0.02,6.03,10.04,8]- undecane-9,11-dione

1983 ◽  
pp. 441 ◽  
Author(s):  
Goverdhan Mehta ◽  
A. Veera Reddy ◽  
Wanda Tacreiter ◽  
T. Stanley Cameron
Keyword(s):  
Crystal Structure ◽  
Lewis Acid ◽  
X Ray

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.

Coordination compounds of indium. Part 43. Indium(III) derivatives of benzenethiol, and the crystal structure of tetraphenylphosphonium bromotris(benzenethiolato)- indate(III), Ph4P[BrIn(SPh)3]

1987 ◽  
Vol 65 (4) ◽  
pp. 804-809 ◽  
Author(s):  
Raj K. Chadha ◽  
Peter C. Hayes ◽  
Hassan E. Mabrouk ◽  
Dennis G. Tuck
Keyword(s):  
Crystal Structure ◽  
Lewis Acid ◽  
Vibrational Spectra ◽  
Coordination Compounds ◽  
Monoclinic Space Group ◽  
Tetrahedral Symmetry ◽  
X Ray ◽  
Cell Dimensions ◽  
Derivatives Of ◽  
Ray Methods

In(SPh)3 is readily prepared by the reaction of InCl3 and NaSPh in methanol. The compound is a Lewis acid, forming 1:1 adducts with 2,2′-bipyridine, 1,10-phenanthroline, N,N,N′,N′-tetramethylethanediamine, bis(diphenylphosphino)ethane, and dimethylsulphoxide, and 1:2 adducts with pyridine, trimethylamine, and triphenylphosphine. Reaction with R4NX (X = Cl, Br, I) or similar salts gives R4N[XIn(SPh)3] salts, which are 1:1 electrolytes. The structure of Ph4P[BrIn(SPh)3] has been determined by X-ray methods. The crystals are monoclinic, space group P21/c, with cell dimensions a = 9.964(3) Å, b = 13.477(3) Å, c = 30.359(7) Å, α = 98.30(2)°, Z = 4, R = 0.0622 for 2924 unique observed reflections. The anion has distorted tetrahedral symmetry in the InBrS3 kernel, with In—Br = 2.527(2) Å, and In—S(av) = 2.450 Å. The vibrational spectra of In(SPh)3 and its derivatives in the region 500–200 cm−1 are discussed.

scholarly journals Crystal structure of a zwitterionic azaallyl zirconiumamide complex bearing a Zr+-μ-CH3—B− moiety and one equivalent of n-hexane as a solvent

IUCrData ◽  
2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Nils Frerichs ◽  
Christian Adler ◽  
Marc Schmidtmann ◽  
Rüdiger Beckhaus
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Lewis Acid ◽  
Tetrahedral Coordination ◽  
X Ray Diffraction ◽  
Coordination Environment ◽  
X Ray ◽  
Strong Lewis Acid ◽  
Distorted Tetrahedral Coordination

The zirconiumamide complex [(cyclohex-1-enyl)cyclohexylamido]bis(dicyclohexylamido)[methyltris(pentafluorophenyl)borato]zirconium(IV) hexane monosolvate, [Zr{N(C6H11)2}2{N(C6H11)(C6H9)}{BCH3(C6F5)3}]·C6H14, is zwitterionic and bears a Zr+—μ-CH3—B− moiety. The reaction of tris(dicyclohexylamido)methylzirconium with the strong Lewis acid tris(pentafluorophenyl)borane results in the formation of an azaallyl zirconium motif by the loss of H2 in one dicyclohexylamido ligand, as shown by single-crystal X-ray diffraction. The ZrIV cation is coordinated to the N atoms of two dicyclohexylamido ligands, the π-system of one azaallyl ligand, and to the μ-CH3—B unit, resulting in a distorted tetrahedral coordination environment. The Zr—N distance to the azaallyl ligand is elongated, whereas the Zr—C distance to this moiety is found to be shortened in comparison with those to the two Cy2N groups (Cy is C6H11).

scholarly journals Synthesis and crystallographic characterization of [2,2-bis(η5-pentamethylcyclopentadienyl)-3,4-bis(trimethylsilyl)-2-zirconafuran-5-one-κO5]triisobutylaluminium

2018 ◽  
Vol 74 (4) ◽  
pp. 566-568
Author(s):  
Vladimir V. Burlakov ◽  
Vyacheslav S. Bogdanov ◽  
Perdita Arndt ◽  
Anke Spannenberg ◽  
Uwe Rosenthal ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Lewis Acid ◽  
X Ray Diffraction ◽  
X Ray

The crystal structure of the title zwitterionic zirconocene complex containing a furanone unit, [AlZr(C10H15)2(C4H9)3(C9H18O2Si2)], is reported. On reacting a zirconafuranone with two equivalents of HAl(i-Bu)2, disproportionation of the Lewis acid results in the formation of a triisobutylaluminium fragment, Al(i-Bu)3, which coordinates to the exocyclic carbonyl O atom of the zirconafuranone ring. Single-crystal X-ray diffraction reveals that the zirconafuranone ring remains intact with coordination of the aluminium to the exocyclic O atom. One of thei-butyl groups is disordered over two sets of sites, with an occupancy ratio of 0.731 (3):0.269 (3).

Neutral and anionic derivatives of toluene-3,4-dithiolatocadmium(II); the crystal structure of di(tetraphenylarsonium) bis(toluene-3,4-dithiolato)cadmate(II)

1983 ◽  
Vol 61 (6) ◽  
pp. 1146-1152 ◽  
Author(s):  
Luis Bustos ◽  
Masood A. Khan ◽  
Dennis G. Tuck
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Least Squares ◽  
Lewis Acid ◽  
Bidentate Ligands ◽  
X Ray ◽  
X Ray Crystallography ◽  
Neutral Bidentate ◽  
Derivatives Of

Cadmium(II) chloride reacts with toluene-3,4-dithiol (H2TDT) to give Cd (TDT), which is apparently a homopolymer in the solid state. Adducts with neutral monodentate and bidentate donors have been prepared. The structure of the salt (Ph4As)2 [Cd(TDT)2] was determined by X-ray crystallography. Crystals of this compound are monoclinic (P21/c), with a = 23.032 (4) Å, b = 12.396(4) Å, c = 22.529(5) Å, β = 111.106(2)°. The structure was refined by least-squares methods to a final R-valueof 0.0469 for 2523 "observed" reflections. The anion is a distorted tetrahedral, mononuclear species with Cd—S bond distances ranging from 2.488(5) Å to 2.531(4) Å. This anion is also a Lewis acid, forming complexes of the type [Cd(TDT)2L]2− with neutral bidentate ligands.

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