Li BY, Lin Y, Du DM. Organocatalytic Asymmetric Mannich Addition of 3-Fluorooxindoles to Dibenzo[
b,
f][1,4]oxazepines: Highly Enantioselective Construction of Tetrasubstituted C-F Stereocenters.
J Org Chem 2019;
84:11752-11762. [PMID:
31408331 DOI:
10.1021/acs.joc.9b01507]
[Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
3-Fluorooxindoles and the dibenzo[b,f][1,4]oxazepane scaffolds are important pharmacophores that have important application in medicinal chemistry. An organocatalyzed asymmetric Mannich reaction of 3-fluorooxindoles with dibenzo[b,f][1,4]oxazepines affording various seven-member cyclic amines containing chiral tetrasubstituted C-F stereocenters was developed. These reactions which were catalyzed by a bifunctional Cinchona alkaloid-derived thiourea catalyst afforded a wide range of substrates in moderate to high yields with excellent diastereo- and enantioselectivities (up to 88% yield, >20:1 dr and >99% ee). A feasible reaction mechanism was also proposed.
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