scholarly journals Sterically Demanding Unsymmetrical Diaryl-λ3-iodanes for Electrophilic Pentafluorophenylation and an Approach to α-Pentafluorophenyl Carbonyl Compounds with an All-Carbon Stereocenter

ChemistryOpen ◽  
2014 ◽  
Vol 3 (6) ◽  
pp. 220-220
Author(s):  
Kohei Matsuzaki ◽  
Kenta Okuyama ◽  
Etsuko Tokunaga ◽  
Motoo Shiro ◽  
Norio Shibata
Keyword(s):  
Carbonyl Compounds ◽  
Sterically Demanding

Complexes of the methyl tris(3,5-dimethylpyrazol-1-yl) gallate ligand, MeGa(N2C5H7)3−, and its hydroxy derivative, MeGa(N2C5H7)2(OH)−. Crystal and molecular structure of [MeGa(N2C5H7)2(OH)]Mo(CO)2(η3-C4H7)

1979 ◽  
Vol 57 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Kenneth R. Breakell ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Least Squares ◽  
Structure Determination ◽  
Carbonyl Compounds ◽  
Crystal And Molecular Structure ◽  
Hydroxy Derivative ◽  
Full Matrix ◽  
Sterically Demanding

The synthesis and coordinating properties of the tridentate tris-chelating ligand, methyl tris(3,5-dimethylpyrazol-1-yl)gallate, MeGa(N2C5H7)3−, are described. Carbonyl and nitrosyl carbonyl compounds of manganese, molybdenum, and tungsten incorporating this ligand are detailed. The ready conversion of the above ligand to the less sterically demanding tris-chelating 'hydroxy' ligand [MeGa(N2C5H7)2(OH)]− occurs in attempted syntheses of the 'η3-allyl' complexes, [MeGa(N2C5H7)3]M(CO)2'η3-allyl', (where M = Mo or W, 'η3-allyl' = η3-C3H5, η3-C4H7). The tridentate chelating nature of this 'hydroxy' ligand is conclusively demonstrated in the crystal structure determination of the complex, [MeGa(N2C5H7)2(OH)]-Mo(CO)2(η3-C4H7). Crystals of this complex are monoclinic, a = 14.020(4), b = 10.110(1), c = 15.493(7) Å, β = 111.58(3)°, Z = 4, space group P21/n. The structure was solved by Patterson and Fourier syntheses and was refined by full-matrix least-squares procedures to a final R of 0.40 and Rw of 0.043 for 3374 reflections with I ≥ 3.5σ(I).

Alkylfluorenyl substituted N-heterocyclic carbenes in copper(i) catalysed hydrosilylation of aldehydes and ketones

2015 ◽  
Vol 44 (31) ◽  
pp. 13991-13998 ◽  
Author(s):  
Matthieu Teci ◽  
Nicolas Lentz ◽  
Eric Brenner ◽  
Dominique Matt ◽  
Loïc Toupet
Keyword(s):  
Copper Complex ◽  
Carbonyl Compounds ◽  
Cost Effective ◽  
Heterocyclic Carbenes ◽  
Sterically Demanding ◽  
Aldehydes And Ketones

An alkylfluorenyl-substituted imidazolylidene copper complex efficiently catalyses the hydrosilylation of functionalized and/or sterically demanding carbonyl compounds, using triethylsilane as cost-effective hydride source; the catalyst displays remarkable stability.

Silicon Assisted Sulfuration: Tetrachlorosilane-Sodium Sulfide-A New Potent Thionating Reagent for Carbonyl Compounds

2007 ◽  
Author(s):  
T. A. Salama ◽  
S. S. Elmorsy ◽  
A. M. Khalil ◽  
M. A. Ismail ◽  
A. S. El-Ahl
Keyword(s):  
Carbonyl Compounds ◽  
Sodium Sulfide

A FACILE SYNTHESIS AND REACTIONS OF AMINO SELENOLO[2,3-b]PYRIDINE CARBOXYLATE

2015 ◽  
Vol 12 (1) ◽  
pp. 3910-3918 ◽  
Author(s):  
Dr Remon M Zaki ◽  
Prof Adel M. Kamal El-Dean ◽  
Dr Nermin A Marzouk ◽  
Prof Jehan A Micky ◽  
Mrs Rasha H Ahmed
Keyword(s):  
Biological Activity ◽  
Carbonyl Compounds ◽  
Mass Spectra ◽  
The Other ◽  
Pyridine Derivatives ◽  
Facile Synthesis ◽  
High Biological Activity ◽  
Basic Hydrolysis ◽  
Pyridine Carboxylate ◽  
Hydrolysis Of

 Incorporating selenium metal bonded to the pyridine nucleus was achieved by the reaction of selenium metal with 2-chloropyridine carbonitrile 1 in the presence of sodium borohydride as reducing agent. The resulting non isolated selanyl sodium salt was subjected to react with various α-halogenated carbonyl compounds to afford the selenyl pyridine derivatives 3a-f  which compounds 3a-d underwent Thorpe-Ziegler cyclization to give 1-amino-2-substitutedselenolo[2,3-b]pyridine compounds 4a-d, while the other compounds 3e,f failed to be cyclized. Basic hydrolysis of amino selenolo[2,3-b]pyridine carboxylate 4a followed by decarboxylation furnished the corresponding amino selenolopyridine compound 6 which was used as a versatile precursor for synthesis of other heterocyclic compound 7-16. All the newly synthesized compounds were established by elemental and spectral analysis (IR, 1H NMR) in addition to mass spectra for some of them hoping these compounds afforded high biological activity.

Regioselective Gas-Phase n-Butane Transfer Dehydrogenation via Silica-Supported Pincer-Iridium Complexes

2020 ◽  
Author(s):  
Boris Sheludko ◽  
Cristina Castro ◽  
Chaitanya Khalap ◽  
Thomas Emge ◽  
Alan Goldman ◽  
...  
Keyword(s):  
Gas Phase ◽  
Active Site ◽  
Lower Cost ◽  
Open Systems ◽  
Iridium Complexes ◽  
Terminal Olefin ◽  
Molecular Precursors ◽  
Sterically Demanding ◽  
Olefin Production ◽  
Steam Cracking

<b>Abstract:</b> The production of olefins via on-purpose dehydrogenation of alkanes allows for a more efficient, selective and lower cost alternative to processes such as steam cracking. Silica-supported pincer-iridium complexes of the form [(≡SiO-<sup>R4</sup>POCOP)Ir(CO)] (<sup>R4</sup>POCOP = κ<sup>3</sup>-C<sub>6</sub>H<sub>3</sub>-2,6-(OPR<sub>2</sub>)<sub>2</sub>) are effective for acceptorless alkane dehydrogenation, and have been shown stable up to 300 °C. However, while solution-phase analogues of such species have demonstrated high regioselectivity for terminal olefin production under transfer dehydrogenation conditions at or below 240 °C, in open systems at 300 °C, regioselectivity under acceptorless dehydrogenation conditions is consistently low. In this work, complexes <a>[(≡SiO-<i><sup>t</sup></i><sup>Bu4</sup>POCOP)Ir(CO)] </a>(<b>1</b>) and [(≡SiO-<i><sup>i</sup></i><sup>Pr4</sup>PCP)Ir(CO)] (<b>2</b>) were synthesized via immobilization of molecular precursors. These complexes were used for gas-phase butane transfer dehydrogenation using increasingly sterically demanding olefins, resulting in observed selectivities of up to 77%. The results indicate that the active site is conserved upon immobilization.

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