A Modular Approach to α-Arylated Carbonyl Compounds via Indium Tris(bistriflylamide)-Catalyzed Regioselective Addition of β-Ketoesters to 1,3-Diynes
✍ Scribed by Masaharu Nakamura; Kohei Endo; Eiichi Nakamura
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 116 KB
- Volume
- 347
- Category
- Article
- ISSN
- 1615-4150
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✦ Synopsis
Abstract
A modular synthesis of α‐arylated carbonyl compounds has been achieved by the combination of an indium‐catalyzed regioselective addition of β‐keto esters to conjugated diynes and a palladium‐catalyzed benzannulation reaction. Indium tris(bistriflylamide), In(NTf~2~)~3~, was found to be an efficient catalyst for the first addition reaction of β‐keto esters to diynes. The reaction proceeds with perfect regioselectivity to give conjugated enynes in high yield. The second palladium‐catalyzed benzannulation proceeds in high to excellent yield and with high regioselectivity for a variety of diynes. This two‐step α‐arylation of carbonyl compounds thus proceeds in a catalytic manner without loss of elements in the starting materials. The reaction may be performed in a single pot without isolation of the product of the first step.