Dai P, Tan X, Luo Q, Yu X, Zhang S, Liu F, Zhang WH. Synthesis of 3-Acyl-isoxazoles and Δ
2-Isoxazolines from Methyl Ketones, Alkynes or Alkenes, and tert-Butyl Nitrite via a Csp
3-H Radical Functionalization/Cycloaddition Cascade.
Org Lett 2019;
21:5096-5100. [PMID:
31194561 DOI:
10.1021/acs.orglett.9b01683]
[Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A novel metal-free tandem Csp3-H bond functionalization of ketones and 1,3-dipolar cycloaddition has been developed. An efficient approach to a variety of oxazole and isoxazoline derivatives is demonstrated using the 1,3-dipolar cycloaddition of alkynes and alkenes to nitrile oxides generated by reactions of methyl ketones with tert-butyl nitrite. This new protocol provides access to a variety of isoxazolines with diverse functionalities. An isoxazole generated in this way was found to have significant antifungal activity.
Collapse