ChemInform Abstract: Broensted-Acid-Mediated Divergent Reactions of Betti Bases with Indoles: An Approach to Chromeno[2,3-b]indoles Through Intramolecular Dehydrogenative C2-Alkoxylation of Indole.
Under Broensted acid catalysis, naphthol-based Betti bases either couple with indoles or undergo a new type of C—C bond cleavage giving diarylmethanes (not shown).