𝔖 Bobbio Scriptorium
✦   LIBER   ✦

A New Approach to Axially Chiral Bipyridine N,N′-Dioxides Bearing Aromatic Substituents and their Use for Catalytic Asymmetric Allylation of Aldehydes with Allyl(trichloro)silane

✍ Scribed by Asato Kina; Toyoshi Shimada; Tamio Hayashi


Publisher
John Wiley and Sons
Year
2004
Tongue
English
Weight
159 KB
Volume
346
Category
Article
ISSN
1615-4150

No coin nor oath required. For personal study only.

✦ Synopsis


Abstract

Palladium‐catalyzed cross‐coupling of bipyridine N,N′‐dioxide 6,6′‐dichloride (R~nap~,R~pyr~)‐1 with the aryl Grignard reagents opened a new approach to axially chiral bipyridine __N,N′‐__dioxides (R)‐2 bearing a variety of aryl groups at the 6 and 6′ positions. One of the __N,N′‐__dioxides (R)‐2d which is substituted with 3,5‐dimethyl‐4‐methoxy groups was found to be highly catalytically active and enantioselective for the asymmetric allylation of aldehydes with allyl(trichloro)silane. The allylation took place with 0.01–0.1 mol % of (R)‐2d giving homoallyl alcohols of up to 94% ee.