Theoretical Investigation on DABCO-Mediated aza Michael Reaction of Sulfonyli-Minoindoline and α,β Unsaturated Aldehyde to Construct 3-Sulfonyl α-Carboline

Abstract

The first theoretical investigation on DABCO-mediated aza-Michael reaction of sulfonyli minoindoline and α,β-unsaturated aldehyde was provided by our DFT calculation. First, 2-aminotosyl indole is given in equilibrium with 2-sulfonamidoindoline via deprotonation with the help of DABCO. Then, it undergoes aza-Michael reaction with α,β-unsaturated aldehyde to form transient carbanion. The ring closure occurs leading to four-membered transient 1,2-thiazetidine, from which the sulfonyl moiety is recovered along with ring opening to release tension. Next, the intramolecular aldol-type reaction proceeds through nucleophilic attack of indole moiety onto aldehyde group followed by proton transfer giving carboannulated product and new hydroxyl group. At last, the final product 3-sulfonyl α-carboline is furnished through dehydration and oxidation. Comparatively, the dehydration is determined to be rate-limiting.

Keywords: DABCO; aza-Michael; Sulfonyl Migration; Intramolecular Aldol; 3-Sulfonyl α-Carboline

Citation

Nan Lu. Theoretical Investigation on DABCO-Mediated aza-Michael Reaction of Sulfonyli-Minoindoline and α,β-Unsaturated Aldehyde to Construct 3-Sulfonyl α-Carboline. WebLog J Mol Cell Biol. wjmcb.2026.i1002. https://doi.org/10.5281/zenodo.22851479