Directed C3-Alkoxymethylation of Indole via Three-Component Cascade Reaction.

An efficient and regioselective C3-alkoxymethylation of indoles has been developed with aldehydes and alcohols via three-component cascade reaction under transition-metal free conditions. This method allows for rapid access to a variety of C3-alkoxymethylaed free (N-H) indole in up to 98% yield with excellent regioselectivity. The titled products are useful building blocks in organic synthesis.