Asymmetric Phase Transfer Catalysed Michael Addition of γ-Butenolide and N-Boc-Pyrrolidone to 4-Nitro-5-styrylisoxazoles

Herein we report the addition of acidic gamma-butenolide and N-Boc-pyrrolidone to 4-nitro-5-styrylisoxazoles, a popular class of cinnamic ester synthetic equivalent. The reactions proceeded under the catalysis of Cinchona-based phase-transfer catalysts. Functionalised gamma-butenolides were obtained in good isolated yields and moderate enantioselectivity (up to 74% ee).

Automated summary

Herein, we report a method for the addition of acidic gamma-butenolide and N-Boc-pyrrolidone to 4-nitro-5-styrylisoxazoles, a popular class of cinnamic ester synthetic equivalent. The reactions were catalyzed by Cinchona-based phase-transfer catalysts, resulting in good isolated yields and moderate enantioselectivity (up to 74% ee) of functionalized gamma-butenolides.