Palladium Acetate and Pd Nanoparticles Loaded Hexamethylenetetramine Anchored Magnetically Retrievable Assemblies for Catalyzing Mizoroki‐Heck Type Mono and Gem‐Dicoupling Reactions. Issue 6 (12th February 2020)

• Record Type: Journal Article
• Authors: Rathod, Prakash B.; Kumar, K. S. Ajish; Kumar, Mukesh; Debnath, A. K.; Pandey, Ashok K.; Athawale, Anjali A.
• Is Part Of: ChemistrySelect. Volume 5:Issue 6(2020)
• Page Start: 1961
• Page End: 1971
• Publication Date: 2020-02-12
• Subjects: Magnetite nanoassembly -- Hexamethylenetetramine -- Pd loading -- Gem-coupling reactions -- single crystal X-ray crystallography; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201903498
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: Fe3 O4 nanoparticles have been covalently coated and chemically modified to anchor hexamethylenetetramine (Fe3 O4 @HMTA) for hosting Pd catalysts such as palladium acetate and palladium nanoparticles. Thus prepared nanocatalyst assemblies have been extensively characterized for their chemical, physical, thermal and magnetic properties. The turnover number and turnover frequency of these catalysts in a model Mizoroki‐Heck coupling reaction involving 3‐acrylomorpholine and iodobenzene with a base as solvent are found to be 186 and 46 h −1, respectively, which are better than that reported in literature. This was attributed to synergistic effect of local basic environment of HMTA rich in tertiary nitrogen content. Gem ‐dicoupled products are formed when reactions are performed in the presence of 1 equivalent of acrylate and 2.1 equivalents of aryl iodide, and gem ‐hetero‐dicoupled product is obtained when reaction is performed in sequential manner. The mechanisms of the formation of the gem ‐homo‐dicoupled and gem ‐hetero‐dicoupled products have been elucidated by using the results obtained from NMR and single crystal X‐ray crystallography studies. Abstract : Pd catalysts loaded magnetically retrievable assemblies developed in the present work exhibit high catalytic activities in Mizoroki‐Heck type mono and gem ‐dicoupling reactions. The mechanisms of the formation of the gem ‐homo‐dicoupled and gem ‐hetero‐dicoupled products have also been elucidated using the results obtained from NMR and single crystal X‐ray crystallography studies.