Abstract

Background: Catalyst-free nucleophilic substitution between hydroxylactam and thiol was developed for the construction of N (acyl), S-acetal skeletons.

Methods: The new protocol provides a series of isoindolo-β-carboline-derived N (acyl), S-acetals in high yields.

Result: The methodology has many advantages, such as catalyst-free, mild reaction conditions, simple operations, high atom-economy, and water as by-product and so on. The reaction mechanism was also discussed.

Keywords: Catalyst-free, nucleophilic substitution, alcohol, thiophenol, hydroxylactam, N-acylimium ion, N, S-acetal.