The Wurtz-Fittig reaction in the preparation of C-silylated calixarenes.
The Wurtz-Fittig reaction of tetraiodo calixarene 3 with Na/Me3SiCl in DME gave a mixture of tetrakis- and tris-silylated calixarenes (6 and 7). Tris(silyl) calixarene 7 was assigned the flattened cone conformation. A model study using p-bromoanisole and p-iodoanisole with Na/Me3SiCl gave the best results with p-bromoanisole in toluene. Attempts to extend this reaction to the tetrabromo calixarene 4 resulted in slow reactions giving mixtures of products. However, the Wurtz-Fittig reaction of the bromo benzyloxycalixarene 5 was faster, giving the debenzylated silyl ether 12.
Hudrlik
Paul F
PF
Department of Chemistry, Howard University, Washington, DC 20059, USA. phudrlik@howard.edu
Arasho
Wondwossen D
WD
Hudrlik
Anne M
AM