An intramolecular cascade cyclization of 2-aryl indoles: efficient methods for the construction of 2,3-functionalized indolines and 3-indolinones

Abstract

Efficient intramolecular N/O-nucleophilic cyclization of 2-aryl indoles has been developed to afford the corresponding 2-aza-3-oxaindolines and 3-indolinones in 80–95% yield. The methods provided convenient access to fused imidazo[1,2-c]oxazolidinone, oxazolidine, or tetrahydro -1,3-oxazine cores under mild conditions.

Brønsted‐Acid‐Mediated Divergent Reactions of Betti Bases with Indoles: An Approach to Chromeno[2,3‐b]indoles through Intramolecular Dehydrogenative C2‐Alkoxylation of Indole

“…A few reports on intramolecular C–O bond formation at the 2‐position of indole leading to indolines are available. [20a], [20b] To the best of our knowledge, there are only a couple of reports on intramolecular dehydrogenative C–O bond formation at the 2‐position of indole. [20b], [20c] Therefore, we became interested in developing a protocol for intramolecular C–O bond formation at the 2‐position of indole to obtain chromeno[2,3‐ b ]indole derivatives.…”