o-Benzenedisulfonimide as a Recyclable Homogeneous Organocatalyst for an Efficient and Facile Synthesis of 4-Amidotetrahydropyran Derivatives Through Prins–Ritter Reaction

Abstract

A highly diastereoselective synthesis of 4-amidotetrahydropyran derivatives has been achieved using a catalytic amount of o-benzenedisulfonimide under mild conditions involving sequential allylation and Prins–Ritter amidation. The oxo-carbenium ion formed in Prins cyclization could be successfully trapped with nitriles through Ritter amidation. The catalyst is highly efficient in promoting both allylation and Prins cyclization with a net addition of nitrile. The catalyst can be easily recovered and reused in subsequent reactions.

GRAPHICAL ABSTRACT

Keywords:

• 4-Amidotetrahydropyrans
• Brønsted acid
• Hosomi–Sakurai allylation
• Prins–Ritter amidation
• recyclable catalyst
• spiro-tetrahydropyrans

Notes

^a All products were characterized by ¹H NMR, IR and mass spectrometry.

^b Yield refers to pure products after chromatography.

^a All products were characterized by ¹H NMR, IR and mass spectrometry.

^b Yield refers to pure products after chromatography.

^a Yield refers to pure product after chomatography.

^a All the reaction were performed in 1 h.

^b Yield refers to the pure product.

^c The reaction was performed in 1 mmol scale using 0.1 mmol of the catalyst (1).