A novel chiral ruthenium porphyrin as highly efficient and selective catalyst for asymmetric cyclopropanations

✍ Scribed by Matthias Frauenkron; Albrecht Berkessel

• Publisher: Elsevier Science
• Year: 1997
• Tongue: French
• Weight: 132 KB
• Volume: 38
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(97)01763-2

✦ Synopsis

The enantiomerically pure ruthenium carbonyl porphyrin 5 is an extremely active and selective catalyst for the asymmetric cyclopropanation of olefins with diazo compounds. At a catalyst loading of only 0.15 mol-%, quantitative yields, excellent diastereoselectivities (trans:cis 96:4) and high enantiomeric excesses (up to 91%) of the product cyclopropanes were achieved in the reaction of styrene with ethyl diazoacetate.