Fajie Wang, Juli Li, Qingyan Hu
Jun 1, 2014
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0
Influential Citations
22
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Journal
European Journal of Organic Chemistry
Abstract
We describe our attempts to fine-tune the reactivity and selectivity of N-fluorobenzenesulfonamide in fluorination reactions by changing the substituents on its phenyl rings. A series of N-fluorobenzenesulfonamides bearing substituents at the ortho, meta, and para positions were prepared, and were used in the enantioselective fluorination of 2-oxindoles catalysed by chiral palladium complexes. Fluorinating reagents 1b, 1c, 1d, 1e, 1h, 1i, and 1j gave similar results to 1a, while 1f, 1g, and 1n gave worse yields and selectivities. Under mild reaction conditions, a series of 3-fluoro-2-oxindoles were obtained in excellent yields (up to 98 %) and enantioselectivities (up to 99 % ee) using N-fluoro-4,4′-difluoro-benzenesulfonamide as the fluorination agent.