Asymmetric Catalysis of Intramolecular Cyclopropanation of 5-Aryl-1-diazo-1-mesitylsulfonyl-5-hexen-2-ones

✍ Scribed by Takashi Sawada; Masahisa Nakada

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 120 KB
• Volume: 347
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/adsc.200505173

✦ Synopsis

Abstract

We have examined the catalytic asymmetric intramolecular cyclopropanation (IMCP) reactions of 5‐aryl‐1‐diazo‐1‐mesitylsulfonyl‐5‐hexen‐2‐ones, and found that the substituent of the 5‐aryl group dramatically changes the enantioselectivity. That is, no enantioselectivity was observed when the substituent was a methoxy group; however, enantioselectivity was moderate when the substituent was a methylenedioxy group or a tert‐butyldimethylsilyloxy group, and it dramatically increased when the substituent was lacking (96% ee) or a benzoyloxy group (93% ee).