Abstract
An efficient, AgOTf and Cu(OTf)2 multicatalytic intramolecular cycloisomerization of 2-alkynylbenzaldoxime is reported. Isoquinoline N-oxides have been found to be deoxygenated to the corresponding quinolines in good yields in dimethylformamide/dichloroethane (v/v 5:1) as solvent at 120 °C.
ACKNOWLEDGMENTS
We thank the National Natural Science Foundation of China (21072102), the Committee of Science and Technology of Tianjin (11JCYBJC04200), and State Key Laboratory of Elemento-organic Chemistry in Nankai University for financial support.
Notes
a Unless otherwise noted all the reactions were performed with 0.5 mmol of 2a and 10 mol% catalyst in 5 ml solvent at 120 °C.
b DMF/DCE (v/v = 1:1).
c DMF/DCE (v/v = 1:3).
d DMF/DCE (v/v = 1:5).
e Isolated yields.
a Unless otherwise noted all the reactions were performed with 0.5 mmol of 2 and 10 mol% AgOTf along with 10 mol% Cu(OTf)2 in 2 ml DMF and DCE (v/v = 5:1) at 120 °C for 24 h.
b Isolated yields.