Abstract
The use of [bmim][BF4], [bmim][PF6], and [bmim][Cl] ILs as the solvents in Pd(II)‐catalyzed enyne cyclization of 2′‐alkenyl 2‐alkynoates in the presence of cupric chloride has been investigated. The Z/E stereoselectivity of the reaction could range from 90:10 to 4:96 by tuning the amount of LiCl in ILs. After the separation of the product, the IL–catalyst mixture could be recovered by treatment with hydrochloric acid and recycled several times without an obvious loss of catalytic activity.
Keywords:
Acknowledgment
We are grateful to the National Natural Science Foundation of China (Grants 20625205, 20572027, and 20332030) and Youth Natural Science Foundation of South China University of Technology for financial support.