An Expedient Variant of Heck Reaction of Alkenyl Nonaflates: Homogeneous Ligand-Free Palladium Catalysis at Room Temperature
作者:Michael A. K. Vogel、Christian B. W. Stark、Ilya M. Lyapkalo
DOI:10.1002/adsc.200600388
日期:2007.5.7
represents a remarkably robust, active and efficient catalyticsystem generally applicable to the coupling with a broad range of terminal olefins including non-activated ones under ambient conditions. It features insensitivity towards atmospheric oxygen and moisture, furnishing uniformly high yields of the anticipated coupling products without the necessity to purify commercial reagents and solvents.
This invention encompasses prostaglandins of the formula ##STR1## wherein R represents hydrogen or lower alkyl having 1 to 6 carbon atoms; R.sub.1 represents hydrogen, vinyl, or lower alkyl having 1 to 4 carbon atoms and the wavy line represents R or S stereochemistry; R.sub.2, R.sub.3, and R.sub.4 are hydrogen or lower alkyl having 1 to 4 carbon atoms or R.sub.2 and R.sub.3 together with carbon Y form a cycloalkenyl having 4 to 6 carbon atoms or R.sub.3 and R.sub.4 together with carbons X and Y form a cycloalkenyl having 4 to 6 carbons. Compounds of this invention have potent gastric antisecretory and cytoprotective properties with unexpectedly lower diarrheogenic side effects.