Multicomponent Synthesis of Substituted 3-Halofurans

Significance

A concise synthesis of substituted 3-halofurans in low to good yields is reported. The one-pot reaction involves sequential acylative Sonogashira coupling of acyl chlorides with terminal alkynes, followed by halide Michael addition, deprotection and cyclocondensation under the acidic conditions of the second step. In one of these sequences, concurrent electrophilic iodination was incorporated. The scope of the reaction has been tested with respect to benzoyl chlorides incorporating both EWGs and EDGs and, less extensively, heterocylic and non-aromatic acid chlorides.