An Alternative Role for Acetylenes: Activation of Fluorobenzenes toward Nucleophilic Aromatic Substitution

作者：Bizier Nicholas P; Wackerly Jay Wm; Braunstein Eric D; Zhang Mengfei; Nodder Stephen T; Carlin Stephen M; Katz Jeffrey L^*

来源：Journal of Organic Chemistry, 2013, 78(12): 5987-5998.

DOI：10.1021/jo400668v

Acetylenes are increasingly versatile functional groups for a range of complexity-building organic transformations and for the construction of desirable molecular architectures. Herein we disclose a previously underappreciated aspect of arylacetylene reactivity by utilizing alkynes as electron-withdrawing groups (EWG) for promoting nucleophilic aromatic substitution (SNAr) reactions. Reaction rates for the substitution of 4-(fluoroethynyl)benzenes by p-cresol were determined by H-1 NMR spectroscopy, and these rate data were used to determine substituent (Hammett) constants for terminal and substituted ethynyl groups. The synthetic scope of acetylene-activated SNAr reactions is broad; fluoroarenes bearing one or two ethynyl groups undergo high-yielding substitution with a variety of oxygen and arylamine nucleophiles.

• 出版日期2013-6-21