[3+2] Cycloaddition reaction between aliphatic alkynes and oxaziridines

Abstract

Alkyl, aryl and acyl-substituted pyrrolidinones as an alternative to isoxazolines can be formed by [3+2] cycloaddition reactions between alkyl oxaziridines and aliphatic alkynes. The structures of isolated products change with oxaziridines Ar groups and with alkynes R and R' groups.

[3+2] Cycloaddition of Oxaziridines with Nitriles: Synthesis of 2,3-Dihydro-1,2,4-Oxadiazoles

“…This and the preceding results are best rationalized by a synchronous [3+2] cycloaddition as recently reported for reaction with alkenes and alkynes [17][18][19] rather than by a 1,3dipolar mechanism, such as for the reactions with nitrones. [10][11][12][13][14][15][16] In summary, we have applied a [3+2] cycloaddition between oxaziridines and nitriles for the synthesis of the 2,3dihydro-1,2,4-oxadiazoles.…”

“…Recently, a [3+2]-cycloaddition reaction between oxaziridines and unactivated terminal alkynes was reported. 17,18 The novelty of this reaction lies in the oxaziridine C-O bond disconnection and the synchronous attack on the triple bond. In detail, the oxygen atom at the internal position and the carbon atom at the terminal position interact.…”

Advances in the Chemistry of Oxaziridines

“…Troisi and co-workers demonstrated that electron-rich alkenes react with oxaziridine 2 to give 3,5-diarylisoxazoline 198 with moderate to excellent cis selectivity (eq 37 ). 134 Aryl 135 and aliphatic 136 terminal alkynes are also competent reaction partners; however, product distributions are highly variable, depending on the substrate. Internal alkynes and benzonitriles 137 have also been utilized to yield 5-acylisoxazolines and 2,3-dihydro-1,2,4-oxadizole products, respectively.…”

Condensed Oxaziridine-Mediated [3+2] Cycloaddition: Synthesis of Polyhetero-bicyclo Compounds

“…It was considerd that the strained oxaziridine ring of these heterobicyclic compounds would be more reactive either than the oxazoline N-oxides 4-13 or than the simple uncondensed oxaziridines. [14][15][16][17] Thus, oxaziridine 6 4a was react-…”