Novel Copper-Catalyzed Multicomponent Cascade Synthesis of Iminocoumarin Aryl Methyl Ethers

A copper(I)-catalyzed one-pot synthesis of iminocoumarin aryl methyl ethers has been developed from ynal, phenol, and sulfonyl azide at ambient conditions via a cascade [3 + 2]-cycloaddition, 1,3-pseudopericyclic ketenimine rearrangement, 1,4-conjugate addition, and aldol-type condensation. This protocol provides a potential route for the construction of a library of iminocoumarin aryl methyl ethers in good yields.