scholarly journals Acid, silver, and solvent-free gold-catalyzed hydrophenoxylation of internal alkynes

2013 ◽  
Vol 9 ◽  
pp. 2002-2008 ◽  
Author(s):  
Marcia E Richard ◽  
Daniel V Fraccica ◽  
Kevin J Garcia ◽  
Erica J Miller ◽  
Rosa M Ciccarelli ◽  
...  
Keyword(s):  
Single Component ◽  
Solvent Free ◽  
Conventional Heating ◽  
Vinyl Ethers ◽  
Silver Salts ◽  
Free Gold ◽  
Internal Alkynes ◽  
Electron Donating Groups

A range of arylgold compounds have been synthesized and investigated as single-component catalysts for the hydrophenoxylation of unactivated internal alkynes. Both carbene and phosphine-ligated compounds were screened as part of this work, and the most efficient catalysts contained either JohnPhos or IPr/SIPr. Phenols bearing either electron-withdrawing or electron-donating groups were efficiently added using these catalysts. No silver salts, acids, or solvents were needed for the catalysis, and either microwave or conventional heating afforded moderate to excellent yields of the vinyl ethers.

scholarly journals Synthesis of a Novel Library of 1-Substituted Pyrido[1,2-a]benzimidazoles

2020 ◽  
Vol 73 (12) ◽  
pp. 1208
Author(s):  
Satyanarayana Gadde ◽  
Yun Cheuk Leung ◽  
Mohan Bhadbade ◽  
Belamy B. Cheung ◽  
David StC. Black ◽  
...  
Keyword(s):  
Nucleophilic Substitution ◽  
Suzuki Coupling ◽  
Solvent Free ◽  
Side Product ◽  
Sterically Demanding ◽  
Electron Donating Groups ◽  
Coupling Type

The reactivity and synthesis of new analogues of pyrido[1,2-a]benzimidazoles have been explored. Twenty-three derivatives bearing phenoxy, thiophenoxy, aniline, and aryl groups at the 1-position were successfully synthesised in 25–91% yield, via nucleophilic substitution, Buchwald–Hartwig amination, and Suzuki coupling type processes. Solvent free synthetic protocols were employed to achieve the nucleophilic substitution of anilines with electron donating groups or moderately electron withdrawing groups on a sterically demanding intermediate (7a). An unusual polycyclic heterocycle was identified as a side-product during this work: a dimeric bis(pyrido[1,2-a]benzimidazole).

Solvent free synthesis of 1-alkoxyphosphonium chlorides for stereoselective multipurpose vinyl ethers

2019 ◽  
Vol 195 (1) ◽  
pp. 37-42
Author(s):  
Zain Maqsood Cheema ◽  
Humaira Yasmeen Gondal ◽  
Hina Siddiqui ◽  
Muhammad Iqbal Choudhary
Keyword(s):  
Solvent Free ◽  
Vinyl Ethers ◽  
Solvent Free Synthesis

scholarly journals Reaction of Carboxylic Acids with Vinyl Ethers under Solvent-free Conditions Using Molecular Iodine as a Catalyst

2013 ◽  
Vol 62 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Yohko Hanzawa ◽  
Yoshio Kasashima ◽  
Kahoko Hashimoto ◽  
Tatsuhiro Sasaki ◽  
Keita Tomisaki ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Molecular Iodine ◽  
Solvent Free ◽  
Vinyl Ethers ◽  
Solvent Free Conditions

Silver-free Gold(I) Catalysts for Organic Transformations

2011 ◽  
Vol 66 (4) ◽  
pp. 329-350 ◽  
Author(s):  
Hubert Schmidbaur ◽  
Annette Schier
Keyword(s):  
Organic Transformations ◽  
Cooperative Effects ◽  
Silver Salts ◽  
Homogeneous Systems ◽  
The Past ◽  
Free Gold ◽  
Photochemical Stability ◽  
Metallophilic Interactions

The majority of gold(I) catalysts employed in organic transformations in homogeneous systems are presently generated in situ by reactions of gold halides AuX or their 1 : 1 complexes [(L)AuX] with silver salts AgY (X = Cl, Br; L = R3P, NHC, tht etc.; Y = BF4, PF6, SbF6, OSO2CF3, OC(O)CF3 etc.). This usage of silver salts is not only economically unfavorable, but also has several practical disadvantages regarding inter alia the thermal and photochemical stability of the reaction mixtures, problems of inexact stoichiometries, difficulties in separation and recycling, and cooperative effects due to Au-Ag metallophilic interactions which can induce a different course of the reactions. There is therefore a move towards syntheses of silver-free homogeneous gold(I) catalysts. The past and current approaches and opportunities are summarized in this review.

Metal-Free Cycloaddition of Internal Alkynes and Multifunctional Azides Under Solvent-Free Conditions

2014 ◽  
Vol 215 (17) ◽  
pp. 1603-1608 ◽  
Author(s):  
Benedict Sandmann ◽  
Bobby Happ ◽  
Jürgen Vitz ◽  
Renzo M. Paulus ◽  
Martin D. Hager ◽  
...  
Keyword(s):  
Solvent Free ◽  
Metal Free ◽  
Solvent Free Conditions ◽  
Internal Alkynes

scholarly journals The Zwitterionic Imidazolium Salt: First Used for Synthesis of 4-Arylidene-2-phenyl-5(4H)-oxazolones under Solvent-Free Conditions

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Baocheng Zhou ◽  
Wenxing Chen
Keyword(s):  
Aromatic Aldehyde ◽  
Hippuric Acid ◽  
Aromatic Aldehydes ◽  
Solvent Free ◽  
Imidazolium Salt ◽  
H Nmr ◽  
Solvent Free Conditions ◽  
High Yields ◽  
Electron Donating Groups

The zwitterionic imidazolium salt was prepared and characterized by1H NMR. It was first used for synthesis of azlactones via Erlenmeyer synthesis from aromatic aldehydes and hippuric acid under solvent-free conditions. It was found that aldehyde substituents play an important role in these reactions. Better conversions and therefore higher isolated yields were observed when electron-withdrawing groups (EWG-) were present in the aromatic aldehyde. Opposite results were shown when electron-donating groups (EDG-) were present in the aromatic aldehyde. However, azlactones were obtained in moderate to high yields.

Sign in / Sign up

Export Citation Format

Share Document