BiCl₃-Catalyzed Diastereoselective Intramolecular [4+2] Cycloaddition Reactions Leading to Pyrazole Annulated New Sulfur Heterocycles

Abstract

Intramolecular [4+2] cycloaddition reactions of N-aryl imines generated in situ from anilines and the S-allyl derivatives of pyrazole aldehydes have been carried out in the presence of catalytic amounts of BiCl₃ to provide the corresponding hexahydropyrazolo [4′,3′:5,6]thiopyrano[4,3-b]quinolines in excellent yields. The reactions are highly diastereoselective and the only cis products are isolated exclusively.

^#IICT Communication No: 020602

Keywords:

• Hetero-Diels–Alder reaction
• Bismuth(III) chloride
• Diastereoselective
• Hexahydropyrazolothiopyranoquinolines

Acknowledgment

ChSR, thanks UGC and ChM, EVR, thanks CSIR, New Delhi for the award of fellowship.

Notes

^#IICT Communication No: 020602