Reagent-Controlled Chemodivergent Approach to Thiazolines and Thiazines from α-N-Hydroxyimino Dithioesters
Abstract
A chemoselective route to thiazolines and thiazines has been devised by heterocyclization of viable α-N-hydroxyimino-β-oxodithioesters with 2-chloroethylamine hydrochloride/3-chloropropylamine hydrochloride, which does not require metals or additives and proceeds at 0–60?°C. The overall transformation involves base mediated intramolecular cyclization of α-N-hydroxyimino-β-oxodithioesters to 4-membered oxazete-4-thione intermediates followed by coupling with chloroalkyl amines via tandem ring cleavage and C?N/C?S bonds formation enabling the construction of thiazolines/thiazines in one-pot. This strategy allows broadening the arsenal of synthetic methods to obtain N,S-heterocycles utilizing substrates prepared according to reported procedures.