Base-Promoted Synthesis of S-Arylisothiazolones via Intramolecular Dehydrative Cyclization of α-Keto-N-acylsulfoximines

Abstract

A base (Et 3 N)-promoted synthesis of 1,4-diarylisothiazolones from α-keto-N-acylsulfoximines has been achieved. The reaction proceeds via α-hydrogen abstraction from sulfoximine, followed by an intramolecular nucleophilic attack at the keto carbonyl to form a tert-hydroxy isothiazolone intermediate. The 1,4-substituted isothiazolone is obtained after dehydration via an E1cB path. This one-pot synthesis of isothiazolinones has a broad substrate scope, has a high atom economy, and provides products with good yields. The ΔE LUMO−HOMO is calculated using Gaussian 16 at the B3LYP/6-31G(d,p) level of theory.

Visible-Light-Triggered Synthesis of N-α-Ketoacylated Sulfoximines by Denitrogenative and Oxidative Functionalization of Vinyl Azides

“…The resulting product ( 3aa ) was successfully obtained with a commendable 68% yield, underscoring the practical applicability of the current approach. To further demonstrate the synthetic versatility of this protocol, the obtained 3aa was employed as a starting material, leading to the synthesis of the corresponding diarylisothiazolones product 4a with a satisfactory yield of 86% (Scheme b) …”