scholarly journals Facile and innovative catalytic protocol for intramolecular Friedel–Crafts cyclization of Morita–Baylis–Hillman adducts: Synergistic combination of chiral (salen)chromium(III)/BF3·OEt2 catalysis

2021 ◽  
Vol 17 ◽  
pp. 2186-2193
Author(s):  
Karthikeyan Soundararajan ◽  
Helen Ratna Monica Jeyarajan ◽  
Raju Subimol Kamarajapurathu ◽  
Karthik Krishna Kumar Ayyanoth
Keyword(s):  
Reaction Conditions ◽  
Effective Catalyst ◽  
Practical Procedure ◽  
Synergistic Combination ◽  
Substituted 1

The chiral (salen)Cr(III)/BF3·OEt2 catalytic combination was found to be an effective catalyst for intramolecular Friedel–Crafts cyclization of electron-deficient Morita–Baylis–Hillman adducts. In presence of mild reaction conditions the chiral (salen)Cr(III)/BF3·OEt2 complex affords 2-substituted-1H-indenes from unique substrates of Morita–Baylis–Hillman adducts via an easy operating practical procedure.

One-Pot Synthesis of 2-Substituted Benzoxazoles Directly from Carboxylic Acids

2008 ◽  
Vol 61 (11) ◽  
pp. 881 ◽  
Author(s):  
Dinesh Kumar ◽  
Santosh Rudrawar ◽  
Asit K. Chakraborti
Keyword(s):  
Carboxylic Acids ◽  
Methanesulfonic Acid ◽  
Acid Chlorides ◽  
Double Bonds ◽  
Reaction Conditions ◽  
One Pot ◽  
Effective Catalyst ◽  
One Pot Synthesis ◽  
Highly Effective

Methanesulfonic acid has been found to be a highly effective catalyst for a convenient and one-pot synthesis of 2-substituted benzoxazoles by the reaction of 2-aminophenol with acid chlorides, generated in situ from carboxylic acids. Aryl, heteroaryl, and arylalkyl carboxylic acids provided excellent yields of the corresponding benzoxazoles. The reaction conditions were compatible with various substituents such as chloro, bromo, nitro, methoxy, cyclopentyloxy, phenoxy, thiophenoxy, and conjugated double bonds. Benzoxazole formation was found to be general with respect to substituted 2-aminophenols.

scholarly journals Synthesis and NMR spectroscopic characterization of Si-substituted 1-silacyclobutene derivatives

2011 ◽  
Vol 9 (1) ◽  
pp. 126-132 ◽  
Author(s):  
Ezzat Khan ◽  
Bernd Wrackmeyer
Keyword(s):  
Magnetic Resonance ◽  
Room Temperature ◽  
Spectroscopic Characterization ◽  
The Other ◽  
Resonance Spectroscopy ◽  
29Si Nmr ◽  
Reaction Conditions ◽  
New Compounds ◽  
Substituted 1

AbstractHydroboration of trialkyn-1-yl(organo)silanes with one equivalent and two equivalents of 9-borabicyclo[3.3.1]nonane, 9-BBN afford dialkyn-1-ylsilanes and alkyn-1-ylsilanes, respectively. The alkyn-1-ylsilane derivatives are stable at room temperature and can be store under dry argon for prolong period of time. These compounds are attractive materials for further rearrangements to afford novel 1-silacyclobutene derivatives bearing Si-alkenyl or Si-alkynyl functionalities. The hydroboration reaction is well controlled by the Si-R1 function, i.e., the starting silanes with R1 = Ph selectively afford hydroboration of one Si-C≡C bond with one equivalent of 9-BBN, leaving the other two functionalities untouched. Under mild reaction conditions (25°C), the starting silanes with R1 = Me lead to mixture containing dialkyn-1-ylsilane, alkyn-1-ylsilane and their respective 1-silacyclobutene derivatives. All new compounds are sensitive towards air and moisture and were studied by multinuclear magnetic resonance spectroscopy (1H, 13C, 11B, 29Si NMR) in solution.

Electron Microscopy of Barium-Promoted Copper Chromite

1985 ◽  
Vol 43 ◽  
pp. 390-391
Author(s):  
J. B. Hall ◽  
J. K. Kouba
Keyword(s):  
Electron Microscopy ◽  
Copper Chromite ◽  
Commercial Application ◽  
Copper Metal ◽  
Fatty Esters ◽  
Reaction Conditions ◽  
Effective Catalyst ◽  
Highly Dispersed ◽  
Linear Alcohols

Copper chromite was reported as an effective catalyst for the hydrogenation of esters to alcohols by Homer Adkins in 1931, and it still remains the catalyst of choice for this reaction. Its most common commercial application is in the hydrogenation of fatty esters to detergent range linear alcohols. Typical reaction conditions are relatively severe: 200-250°C and 2000-4000 psig hydrogen. Barium is often used as a promoter and such a catalyst is prepared by codeposition of barium and copper chromates followed by calcination to the mixed chromite. The catalyst is usually activated by reduction with hydrogen which is believed to generate highly dispersed copper metal. The barium supposedly retards overreduction of the catalyst and ameliorates sulfate poisoning.Knowledge of the distribution and association of the Ba, Cu, and Cr catalyst components is important in understanding its function and in the design of better catalysts.

scholarly journals AuPd-nNiO as an effective catalyst for the base-free oxidation of HMF under mild reaction conditions

2019 ◽  
Vol 21 (15) ◽  
pp. 4090-4099 ◽  
Author(s):  
Danilo Bonincontro ◽  
Alice Lolli ◽  
Alberto Villa ◽  
Laura Prati ◽  
Nikolaos Dimitratos ◽  
...  
Keyword(s):  
High Activity ◽  
Reaction Conditions ◽  
Effective Catalyst ◽  
Furandicarboxylic Acid ◽  
Free Oxidation

AuPd nanoparticles supported on NiO exhibit high activity and stability in the base free oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA).

scholarly journals Reaktionen 4,4-Bis(trifluormethyl)-substituierter Heterodiene mit Alkinen / Reactions of 4,4-Bis(trifluoromethyl) Substituted Heterodienes with Alkynes

1989 ◽  
Vol 44 (10) ◽  
pp. 1298-1312 ◽  
Author(s):  
Klaus Burger ◽  
Norbert Sewald ◽  
Erasmus Huber ◽  
Ralph Ottlinger
Keyword(s):  
Reaction Conditions ◽  
Open Chain ◽  
Substituted 1

4,4-Bis(trifluoromethyl) substituted 1-oxa-3-azabuta-1,3-dienes (1) and alkynes react to give open-chain trifluoromethyl substituted N-propargylic amides (4), 4H-1,3-oxazines (5) and 2-oxazolines (6, 7), respectively. The selectivity of the reaction can be controlled effectively by the reaction conditions used.

ChemInform Abstract: P2O5/SiO2: A Simple and Effective Catalyst for the Synthesis of N-Substituted 1-Alkyl and 1-Aryl 3-Aminoisoquinolines.

ChemInform ◽  
2013 ◽  
Vol 44 (42) ◽  
pp. no-no
Author(s):  
Leticia J. Mendez ◽  
Alicia S. Canepa ◽  
Ruben Rimada ◽  
Rodolfo D. Bravo
Keyword(s):  
Effective Catalyst ◽  
Substituted 1

Hierarchically porous AlPO-5-based microspheres as heterogeneous catalysts for the synthesis of 5-substituted 1H-tetrazoles via [3+2] cycloaddition

2014 ◽  
Vol 38 (7) ◽  
pp. 3078-3083 ◽  
Author(s):  
Dan Kong ◽  
Yanyan Liu ◽  
Juan Zhang ◽  
Hongbian Li ◽  
Xiangyu Wang ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Hierarchically Porous ◽  
Effective Catalyst ◽  
Substituted 1

W-containing AlPO-5 microspheres were effective catalyst for the synthesis of 5-substituted 1H-tetrazoles by [3+2] cycloaddition.

Sign in / Sign up

Export Citation Format

Share Document