Single Step Synthesis of Acetylene-Substituted Oxacalix[4]arenes
作者:Jay Wm. Wackerly、Mengfei Zhang、Stephen T. Nodder、Stephen M. Carlin、Jeffrey L. Katz
DOI:10.1021/ol5010627
日期:2014.6.6
Oxacalixarenes bearing acetylene groups are synthesized in a single step by nucleophilic aromatic substitution reactions of orcinol with various 1,5-diethynyl-2,4-difluorobenzenes. Thermodynamic equilibration of the cyclooligomer mixtures was accomplished for arylethynyl activating groups, leading to increased yields of the corresponding oxacalix[4]arenes. A 1,3-alternate macrocycle conformation is observed in the solid state, presenting a large V-shaped pi-surface.
An Alternative Role for Acetylenes: Activation of Fluorobenzenes toward Nucleophilic Aromatic Substitution
作者:Nicholas P. Bizier、Jay Wm. Wackerly、Eric D. Braunstein、Mengfei Zhang、Stephen T. Nodder、Stephen M. Carlin、Jeffrey L. Katz
DOI:10.1021/jo400668v
日期:2013.6.21
aspect of arylacetylene reactivity by utilizing alkynes as electron-withdrawing groups (EWG) for promoting nucleophilicaromaticsubstitution (SNAr) reactions. Reaction rates for the substitution of 4-(fluoroethynyl)benzenes by p-cresol were determined by 1H NMR spectroscopy, and these rate data were used to determine substituent (Hammett) constants for terminal and substituted ethynyl groups. The synthetic