Enantiodivergent [4+2] Cycloaddition of Dienolates by Polyfunctional Lewis Acid/Zwitterion Catalysis.
Enantiodivergent [4+2] Cycloaddition of Dienolates by Polyfunctional Lewis Acid/Zwitterion Catalysis.
复制标题
DOI：
10.1002/anie.202009093
复制
发表时间：
2020-11-02
期刊：
影响因子：
--
通讯作者：
Peters R
中科院分区：
文献类型：
--
作者：
Miskov-Pajic V;Willig F;Wanner DM;Frey W;Peters R
Diels–Alder reactions have become established as one of the most effective ways to prepare stereochemically complex six‐membered rings. Different catalysis concepts have been reported, including dienophile activation by Lewis acids or H‐bond donors and diene activation by bases. Herein we report a new concept, in which an acidic prodiene is acidified by a Lewis acid to facilitate deprotonation by an imidazolium–aryloxide entity within a polyfunctional catalyst. A metal dienolate is thus formed, while an imidazolium–ArOH moiety probably forms hydrogen bonds with the dienophile. The catalyst type, readily prepared in few steps in high overall yield, was applied to 3‐hydroxy‐2‐pyrone and 3‐hydroxy‐2‐pyridone as well as cyclopentenone prodienes. Maleimide, maleic anhydride, and nitroolefin dienophiles were employed. Kinetic, spectroscopic, and control experiments support a cooperative mode of action. High enantioselectivity was observed even with unprecedented TONs of up to 3680. In an efficient approach to catalytic asymmetric [4+2] cycloaddition, acidic prodienes were deprotonated by a betaine species to form a copper dienolate, and the dienophile was activated by hydrogen‐bond formation (see scheme). The polyfunctional catalyst promoted the transformation with high enantioselectivity as well as high turnover numbers.
登录
查看更多内容
影响因子：
46.2
作者：
Marcos V;Alemán J
通讯作者：
Alemán J
影响因子：
16.6
作者：
Bures, Jordi
通讯作者：
Bures, Jordi
影响因子：
15
作者：
Baxter, Ryan D.;Sale, David;Blackmond, Donna G.
通讯作者：
Blackmond, Donna G.
影响因子：
2.8
作者：
Mechler, Melanie;Frey, Wolfgang;Peters, Rene
通讯作者：
Peters, Rene
影响因子：
5.2
作者：
Kipassa, Nsiama Tienabe;Okamura, Hiroaki;Iwagawa, Tetsuo
通讯作者：
Iwagawa, Tetsuo