Ruthenium byproducts from ring-closing metathesis reactions can be removed by refluxing the crude reaction mixture with resin-bound triphenylphosphine oxide (TPPO) in toluene or by stirring with dimethyl sulfoxide (DMSO) and silica gel at room temperature. Residual levels of ruthenium can be achieved that are as low as 0.04 microg per 5 mg of product when a combination of TPPO, DMSO, and silica gel is used. The polymer-bound TPPO retained its efficiency after being recycled six times.
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http://dx.doi.org/10.1007/s11030-005-2480-6 | DOI Listing |
Org Lett
December 2024
Department of Chemistry, Rutgers University, 73 Warren Street, Newark, New Jersey 07102, United States.
Molecular editing of quinazolinones to isoquinolines by a novel ruthenium-catalyzed [4+2] annulation with sulfoxonium ylides has been developed. The method permits the precise and rapid assembly of multisubstituted aminoisoquinolines, a class of heterocycles that play a privileged role in organic synthesis and pharmaceutical development. This new catalytic process exhibits novel programmability, including directed C-H acetylation, nucleophilic cyclization, and alcoholysis.
View Article and Find Full Text PDFChem Rec
December 2024
Artificial Photosynthesis Laboratory, Science Block, Department of Chemistry and Chemical Biology, Indian Institute of Technology (Indian School of Mines) Dhanbad, Jharkhand, 826004, India.
Formic acid (HCOOH) is a promising source of hydrogen energy that can be used to produce hydrogen in a more economical and ecological way. Formic acid is a simple carboxylic acid with a high hydrogen concentration and is generally stable, making it useful as a hydrogen transporter. Catalytic dehydrogenation is usually used to extract hydrogen from formic acid; this process releases hydrogen gas and yields carbon dioxide as a byproduct.
View Article and Find Full Text PDFChemistry
November 2024
Department of Chemistry, Indian Institute of Technology Guwahati, 781039, Guwahati, Assam, India.
Oxidative cleavage of olefins is a useful reaction in organic synthesis. The most well-known catalytic system is the osmium based Lemieux-Johnson catalyst, which generally requires high catalyst loading and tends to suffer from rapid overoxidation to produce the acid predominantly. Hence, the development of a mild, general, and selective method toward the oxidative cleavage of alkenes to carbonyl compounds is highly desired.
View Article and Find Full Text PDFEnviron Sci Technol
November 2024
State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
Org Lett
November 2024
Key Laboratory of Green Chemistry & Technology, Ministry of Education College of Chemistry, Sichuan University, Chengdu 610064, P. R. China.
Described herein is the synthesis of 2-pyrazolines via acceptorless dehydrogenative coupling of allylic alcohols with hydrazines based on a Ru(CO)/NHC-phosphine-phosphine ligand catalytic system. The reaction not only exhibits low catalyst loading (only 0.3 mol %), wide substrate scope, good to excellent yields, and high selectivity but also omits the use of sacrificial hydrogen acceptor with only H and HO as byproducts, making the reaction green and atom-economical.
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