Uncatalyzed Reactions of Schiff Bases with Cyanopropargyl Alcohols. Synthesis of Functionalized 1,3-Oxazolidines

Schiff bases reacted with cyanopropargyl alcohols under catalyst-free and solvent-free conditions (80 degrees C, 10-12 h) to give functionalized 1,3-oxazolidines in up to 82% yield. The reaction involves a sequence of transformations, which includes the formation of a 1,3-dipolar intermediate via addition of the neutral N-nucleophile to the activated triple bond, proton transfer from the hydroxy group to the carbanionic center of that intermediate, and intramolecular attack of the oxygen-centered anion on the former C=N carbon atom of Schiff base with closure of 1,3-oxazolidine ring.

Automated summary

Schiff bases reacted with cyanopropargyl alcohols under catalyst-free and solvent-free conditions (80 degrees C, 10-12 h) to give functionalized 1,3-oxazolidines in up to 82% yield. The reaction involves a sequence of transformations, which includes the formation of a 1,3-dipolar intermediate via addition of the neutral N-nucleophile to the activated triple bond, proton transfer from the hydroxy group to the carbanionic center of that intermediate, and intramolecular attack of the oxygen-centered anion on the former C=N carbon atom of Schiff base with closure of 1,3-oxazolidine ring.