Tricarbonylchromium complexes of 25,26,27,28-tetrapropoxycalix-arene conformers (l4Pr) were synthesized. Since the benzene ring is activated through complexation with Cr(CO)3, the functional groups (e.g. —D, —CH3, and —CHO) could be selectively introduced into the Cr(CO)3-complexed benzene ring. The substitution reaction occurred mainly at the p-position. The para selectivity was attributed to the steric crowding being relatively lower than that around the meta and benzyl position. This view was supported by the X-ray crystallographic study of 1,3-alternate-l4Pr. (CO)3. This is a novel and general methodology for selective introduction of functional groups into calix[n]arenes.
All Science Journal Classification (ASJC) codes