Gold Catalysis: Observation of a Two-Fold Intermolecular Hydroarylation of Unactivated C–C Triple Bonds

2006 ◽  
Vol 2006 (19) ◽  
pp. 4340-4342 ◽  
Author(s):  
A. Stephen K. Hashmi ◽  
M. Carmen Blanco
Keyword(s):  
Gold Catalysis ◽  
Triple Bonds

Gold Catalyzed Hydroamination of Propargylic Alcohols: Controlling Divergent Reaction Pathways to Access 1,3-Aminoalcohols, 3-Hydroxyketones or 3-Aminoketones

2018 ◽  
Author(s):  
Victor Laserna ◽  
Tom Sheppard
Keyword(s):  
Gold Catalysis ◽  
Reaction Pathways ◽  
High Yield ◽  
Reaction Conditions ◽  
Propargylic Alcohols ◽  
Catalytic Quantity ◽  
Selective Formation ◽  
General Method

A versatile approach to the valorization of propargylic alcohols is reported, enabling controlled access to three different products from the same starting materials. Firstly, a general method for the hydroamination of propargylic alcohols with anilines is described using gold catalysis to give 3-hydroxy imines with complete regioselectivity. These 3-hydroxyimines can be reduced to give 1,3-aminoalcohols with high syn seletivity. Alternatively, by using a catalytic quantity of aniline, 3-hydroxyketones can be obtained in high yield directly from propargylic alcohols. Further manipulation of the reaction conditions enables the selective formation of 3-aminoketones via a rearrangement/hydroamination pathway.<br>

scholarly journals Water Can Accelerate Homogeneous Gold Catalysis

2021 ◽  
Author(s):  
Philipp Stein ◽  
Matthias Rudolph ◽  
A. Stephen K. Hashmi
Keyword(s):  
Gold Catalysis

scholarly journals Predicting the new carbon nanocages, fullerynes: a DFT study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Qasemnazhand ◽  
Farhad Khoeini ◽  
Farah Marsusi
Keyword(s):  
Density Functional Theory ◽  
Lithium Ion Batteries ◽  
Density Functional ◽  
Lithium Ion ◽  
The Other ◽  
Electron Affinities ◽  
Chemical Formula ◽  
Functional Theory ◽  
Triple Bonds ◽  
Structural And Electronic Properties

AbstractIn this study, based on density functional theory, we propose a new branch of pseudo-fullerenes which contain triple bonds with sp hybridization. We call these new nanostructures fullerynes, according to IUPAC. We present four samples with the chemical formula of C4nHn, and the structures derived from fulleranes. We compare the structural and electronic properties of these structures with those of two common fullerenes and fulleranes systems. The calculated electron affinities of the sampled fullerynes are negative, and much smaller than those of fullerenes, so they should be chemically more stable than fullerenes. Although fulleranes also exhibit higher chemical stability than fullerynes, but pentagon or hexagon of the fullerane structures cannot pass ions and molecules. Applications of fullerynes can be included in the storage of ions and gases at the nanoscale. On the other hand, they can also be used as cathode/anode electrodes in lithium-ion batteries.

scholarly journals First total synthesis of the (±)-2-methoxy-6-heptadecynoic acid and related 2-methoxylated analogs as effective inhibitors of the Leishmania topoisomerase IB enzyme

2012 ◽  
Vol 84 (9) ◽  
pp. 1867-1875 ◽  
Author(s):  
Néstor M. Carballeira ◽  
Michelle Cartagena ◽  
Fengyu Li ◽  
Zhongfang Chen ◽  
Christopher F. Prada ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Total Synthesis ◽  
Leishmania Donovani ◽  
Dna Topoisomerase ◽  
Triple Bonds ◽  
Weak Intermolecular Interactions ◽  
Topoisomerase Ib ◽  
Effective Inhibition ◽  
Acetylenic Fatty Acid

The fatty acids (±)-2-methoxy-6Z-heptadecenoic acid, (±)-2-methoxy-6-hepta-decynoic acid, and (±)-2-methoxyheptadecanoic acid were synthesized and their inhibitory activity against the Leishmania DNA topoisomerase IB enzyme (LdTopIB) determined. Both 2-OMe-17:1 fatty acids were synthesized from 4-bromo-1-pentanol, the olefinic fatty acid in 10 steps and in 7 % overall yield, while the acetylenic fatty acid in 7 steps and in 14 % overall yield. The 2-OMe-17:0 acid was prepared in 6 steps and in 42 % yield from 1-hexa-decanol. The 2-OMe-17:1 acids inhibited LdTopIB, with the acetylenic acid displaying an EC50 = 16.6 ± 1.1 μM, but the 2-OMe-17:0 acid did not inhibit LdTopIB. The (±)-2-methoxy-6Z-heptadecenoic acid preferentially inhibited LdTopIB over the human TopIB enzyme. Unsaturation seems to be a prerequisite for effective inhibition, rationalized in terms of weak intermolecular interactions between the active site of LdTopIB and either the double or triple bonds of the fatty acids. Toxicity toward Leishmania donovani promastigotes was also investigated, resulting in the order acetylenic &gt; olefinic &gt; saturated with the (±)-2-methoxy-6-heptadecynoic acid displaying an EC50 = 74.0 ± 17.1 μM. Our results indicate that α-methoxylation decreases the toxicity of C17:1 fatty acids toward L. donovani promastigotes, but improves their selectivity index.

scholarly journals A gold-catalyzed alkyne-diol cycloisomerization for the synthesis of oxygenated 5,5-spiroketals

2011 ◽  
Vol 7 ◽  
pp. 570-577 ◽  
Author(s):  
Sami F Tlais ◽  
Gregory B Dudley
Keyword(s):  
Transition Metal ◽  
Lewis Acids ◽  
Gold Catalysis ◽  
Late Transition Metal ◽  
Efficient Synthesis ◽  
Highly Efficient ◽  
Late Transition

A highly efficient synthesis of oxygenated 5,5-spiroketals was performed towards the synthesis of the cephalosporolides. Gold(I) chloride in methanol induced the cycloisomerization of a protected alkyne triol with concomitant deprotection to give a strategically hydroxylated 5,5-spiroketal, despite the potential for regiochemical complications and elimination to furan. Other late transition metal Lewis acids were less effective. The use of methanol as solvent helped suppress the formation of the undesired furan by-product. This study provides yet another example of the advantages of gold catalysis in the activation of alkyne π-systems.

Molecular orbital and spectroscopic studies of triple bonds between transition-metal atoms. 2. The d5-d5 Re2Cl4(PR3)4 compounds

1983 ◽  
Vol 105 (9) ◽  
pp. 2606-2611 ◽  
Author(s):  
Bruce E. Bursten ◽  
F. Albert Cotton ◽  
Phillip E. Fanwick ◽  
George G. Stanley ◽  
Richard A. Walton
Keyword(s):  
Transition Metal ◽  
Molecular Orbital ◽  
Spectroscopic Studies ◽  
Triple Bonds ◽  
Metal Atoms ◽  
Transition Metal Atoms

Molecular diversity through gold catalysis with alkynes

2007 ◽  
pp. 333-346 ◽  
Author(s):  
Eloísa Jiménez-Núñez ◽  
Antonio M. Echavarren
Keyword(s):  
Molecular Diversity ◽  
Gold Catalysis
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