Copper (I) 1,3-R2-3,4,5,6-tetrahydropyrimidin-2-ylidenes (R=mesityl, 2-propyl): synthesis, X-ray structures, immobilization and catalytic activity
| Autor: | Dongren Wang, Klaus Wurst, Michael R. Buchmeiser, Bhasker Bantu |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Atom-transfer radical-polymerization
Hydrosilylation Organic Chemistry Radical polymerization chemistry.chemical_element Homogeneous catalysis General Medicine Biochemistry Copper Catalysis chemistry.chemical_compound Monomer chemistry Drug Discovery Polymer chemistry Organic chemistry Reactivity (chemistry) Methyl methacrylate Carbene |
| Zdroj: | Tetrahedron. 61:12145-12152 |
| ISSN: | 0040-4020 |
| DOI: | 10.1016/j.tet.2005.07.116 |
| Popis: | The synthesis of novel copper (I) N-heterocyclic carbene complexes is described. Thus, reaction of CuX with 1,3-di(2-propyl)-3,4,5,6-tetrahydropyrimidin-2-ylidene yields CuX(1,3-di(2-propyl)-3,4,5,6-tetrahydropyrimidin-2-ylidene) (X=Cl, ( 1a ), Br ( 1b )); however, reaction of CuCl with 1,3-dimesityl-3,4,5,6-tetrahydropyrimidin-2-ylidene yields the bis-N-heterocylcic carbene complex Cu(1,3-dimesityl-3,4,5,6-tetrahydropyrimidin-2-ylidene)2+CuBr2− ( 2 ). A supported version of 1 , i.e. PS-DVB–CH2–OCO–CF2–CF2–CF2–COOCu(1,3-di(2-propyl)-3,4,5,6-tetrahydropyrimidin-2-ylidene) ( 3 ) was prepared from 1 and PS-DVB–CH2–OCO–CF2–CF2–CF2–COOAg. A copper loading of 4.15 μmol/g was realized. The new compounds were used as catalysts in carbonyl hydrosilylation and cyanosilylation reactions. Excellent reactivity was observed, giving raise to turn-over numbers (TONs) of up to 100,000. Compounds 1a , 1b , and 2 have also been used as catalysts for the atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA). A linear conversion of monomer with time was observed, however, no control over molecular weight of PMMA was observed. |
| Databáze: | OpenAIRE |
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