Base-controlled [3+3] cycloaddition of isoquinoline N-oxides with azaoxyallyl cations

Yuanyuan An; Hongguang Xia; Jie Wu

doi:10.1039/c6cc03650c

Base-controlled [3+3] cycloaddition of isoquinoline N-oxides with azaoxyallyl cations

Chem Commun (Camb). 2016 Aug 16;52(68):10415-8. doi: 10.1039/c6cc03650c.

Authors

Yuanyuan An¹, Hongguang Xia², Jie Wu³

Affiliations

¹ Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China. jie_wu@fudan.edu.cn.
² Department of Biochemistry and Molecular Biology, Zhejiang University School of Medicine, Hangzhou 310058, China. hongguangxia@zju.edu.cn.
³ Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China. jie_wu@fudan.edu.cn and State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.

PMID: 27484327
DOI: 10.1039/c6cc03650c

Abstract

A base-controlled [3+3] cycloaddition reaction of isoquinoline N-oxides with azaoxyallyl cations is developed. 1,11b-dihydro-[1,2,4]oxadiazino[3,2-a]isoquinolin-2(3H)-ones are obtained when isoquinoline N-oxides are treated with α-halohydroxamates in the presence of sodium carbonate, while 2-(isoquinolin-1-yloxy)acetamides are unexpectedly produced when the base is changed to cesium carbonate. This transformation proceeds through an azaoxyallyl cation generated in situ from α-bromohydroxamate, and the [3+3] cycloaddition reaction is the key step for the final outcome.