Ligand-Controlled Enantioselective [2 + 2] Cycloaddition of Oxabicyclic Alkenes with Terminal Alkynes Using Chiral Iridium Catalysts

Oxabicyclic alkenes can react with electron-deficient terminal alkynes in the presence of a gold catalyst under mild conditions, affording the corresponding addition products in moderate yields. When using alkynyl esters as substrates, the (Z)-acrylate derivatives are obtained. Using but-3-yn-2-one (ethynyl ketone) as a substrate, the corresponding addition product is obtained with (E)-configuration. The proposed mechanism of these reactions is also discussed.

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Switch of Addition and Ring-Opening Reactions of Oxabicyclic Alkenes with Terminal Alkynes by sp2-C,P- and sp3-C,P-Palladacycle Catalysis

Organometallics ◽

10.1021/om400653x ◽

2013 ◽

Vol 32 (16) ◽

pp. 4465-4468 ◽

Cited By ~ 26

Author(s):

Dong-Liang Mo ◽

Bo Chen ◽

Chang-Hua Ding ◽

Li-Xin Dai ◽

Guang-Cun Ge ◽

...

Keyword(s):

Ring Opening ◽

Terminal Alkynes ◽

Ring Opening Reactions ◽

Oxabicyclic Alkenes

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A High Resolution Study of Alumina Supported Iridium Catalysts

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600000878 ◽

1980 ◽

Vol 38 ◽

pp. 202-203

Author(s):

C. Stoeckert ◽

B. Etherton ◽

M. Beer ◽

J. Gryder

Keyword(s):

Electron Microscope ◽

High Resolution ◽

Metal Particles ◽

Optical Transfer Function ◽

Particle Sizes ◽

Iridium Catalysts ◽

Transmission Electron ◽

Optical Transfer ◽

Conventional Transmission Electron Microscope ◽

Resolution Study

The interpretation of the activity of catalysts requires information about the sizes of the metal particles, since this has implications for the number of surface atoms available for reaction. To determine the particle dimensions we used a high resolution STEM1. Such an instrument with its simple optical transfer function is far more suitable than a conventional transmission electron microscope for the establishment of particle sizes. We report here our study on the size and number distribution of Ir particles supported on Al2O3 and also examine simple geometric models for the shape of Ir particles.

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Alkane upgrading effected by silica-supported pincer-iridium catalysts: Evidence of a shared active site with solution-phase species

10.1021/scimeetings.0c06766 ◽

2020 ◽

Author(s):

Alan Goldman ◽

Boris Sheludko ◽

Fuat Celik ◽

Cristina Castro

Keyword(s):

Active Site ◽

Solution Phase ◽

Iridium Catalysts

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Indium(III) Catalyzed Direct sp3-sp C-C Bond Formation from Alcohols and Terminal Alkynes

Letters in Organic Chemistry ◽

10.2174/1570178611310080004 ◽

2013 ◽

Vol 10 (8) ◽

pp. 555-561 ◽

Cited By ~ 5

Author(s):

Guangming Nan ◽

Jun Zhou

Keyword(s):

Bond Formation ◽

Terminal Alkynes

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Transition Metal-Catalyzed Carboxylation of Terminal Alkynes with CO2

Mini-Reviews in Organic Chemistry ◽

10.2174/1570193x15666180101150819 ◽

2018 ◽

Vol 15 (4) ◽

pp. 283-290 ◽

Cited By ~ 8

Author(s):

Chang Qiao ◽

Yu Cao ◽

Liang-Nian He

Keyword(s):

Transition Metal ◽

Terminal Alkynes ◽

Transition Metal Catalyzed ◽

Metal Catalyzed

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Synthesis of Novel 1,2,3-Triazole Derivatives of Isocoumarins and 3,4-Dihydroisocoumarin with Potential Antiplasmodial Activity In Vitro

Medicinal Chemistry ◽

10.2174/1573406416666200602161047 ◽

2020 ◽

Vol 16 ◽

Author(s):

Lucas da Silva Santos ◽

Matheus Fillipe Langanke de Carvalho ◽

Ana Claudia de Souza Pinto ◽

Amanda Luisa da Fonseca ◽

Julio César Dias Lopes ◽

...

Keyword(s):

Triazole Ring ◽

Antiplasmodial Activity ◽

World Health ◽

Dipolar Cycloaddition ◽

Terminal Alkynes ◽

The World ◽

Ic50 Values ◽

Derivatives Of ◽

Active Substances

Background: Malaria greatly affects the world health, having caused more than 228 million cases only in 2018. The emergence of drug resistance is one of the main problems in its treatment, demonstrating the urge for the development of new antimalarial drugs. Objective: Synthesis and in vitro antiplasmodial evaluation of triazole compounds derived from isocoumarins and a 3,4- dihydroisocoumarin. Method: The compounds were synthesized in 4 to 6-step reactions with the formation of the triazole ring via the Copper(I)-catalyzed 1,3-dipolar cycloaddition between isocoumarin or 3,4-dihydroisocoumarin azides and terminal alkynes. This key reaction provided compounds with an unprecedented connection of isocoumarin or 3,4-dihydroisocoumarin and the 1,2,3-triazole ring. The products were tested for their antiplasmodial activity against a Plasmodium falciparum chloroquine resistant and sensitive strains (W2 and 3D7, respectively). Results: Thirty-one substances were efficiently obtained by the proposed routes with an overall yield of 25-53%. The active substances in the antiplasmodial test displayed IC50 values ranging from 0.68-2.89 μM and 0.85-2.07 μM against W2 and 3D7 strains, respectively.

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