Sequential one-pot synthesis of N-sulfonyl spiroaziridine oxindoles from spiroepoxy oxindoles

Org Biomol Chem. 2021 Jun 30;19(25):5624-5631. doi: 10.1039/d1ob00541c.

Abstract

The N-sulfonyl spiroaziridine oxindole is a recently developed versatile precursor in the synthesis of a wide range of 3,3-disubstituted spirooxindoles. It is usually prepared in three steps from isatin and needs costly and hardly available sulfinimides and hazardous peracid. A sequential and one-pot direct strategy for the synthesis of terminal N-sulfonyl spiroaziridine oxindoles has been developed under ambient conditions with excellent yields (up to 95%) from easily accessible spiroepoxy oxindoles by regioselective amination with aqueous ammonia and a subsequent ring enclosure reaction of the resulting 1,2-amino alcohol using easily available sulfonyl chloride and a base. Other salient features of the protocol include inexpensive substrate requirement and the ease of isolation of the desired product by performing single column chromatographic purification after two consecutive steps.

Publication types

  • Research Support, Non-U.S. Gov't