Soluble Polymer-Supported Ruthenium Porphyrin Catalysts for Epoxidation, Cyclopropanation, and Aziridination of Alkenes
作者:Jun-Long Zhang、Chi-Ming Che
DOI:10.1021/ol0259138
日期:2002.5.1
[reaction: see text] Attachment of poly(ethyleneglycol) (PEG) to ruthenium porphyrin via a covalent etheric bond gives soluble polymer-supported ruthenium catalysts 3-5. These catalysts exhibit high reactivity and selectivity toward alkene epoxidation with 2,6-dichloropyridine N-oxide and alkene cyclopropanation with diazo compounds. The application of these catalysts in the synthesis of unstable
The intramolecularcyclopropanation of various trans-allylic diazoacetates and alkenyl diazoketones has been achieved with excellent enantioselectivities of up to 98% ee and in quantitative yields by using a water-solubleruthenium(II)/hydroxymethyl(phenyl)oxazoline catalyst in a water/ether biphasic medium. The catalyst could be reused at least five times.