Reactions for the functionalization of the lower rim of calix[4]resorcinarenes and synthesis of η6-[1,3-bis-(2′4 ′6′-trimethoxybenzyl)benzene]tricarbonylchromium

In this project, the intent was to design and synthesize a calixresorcinarene that has a cleft in the tail of the molecule and would serve in molecular recognition processes. Calix[4]resorcinarene (79) was prepared and treated with NBS and Me2SiCl2 to obtain a bridged resorcinarene (82) with a rigid cavity and to protect the phenol groups at the top rim of the molecule. Many reactions were tried on 82 in order to functionalize the pendant groups at the rear end of the molecule, but none of the conditions met with success. Compound 82 was soluble only in DMF, therefore all the reactions were performed in that solvent. This limitation may have influenced the outcome of the reactions. The synthesis of basic cyclophane frameworks very similar to calixarene molecules was also studied in this project. Chromium complexes of m-xylene-α, α′-diol (91) and 5-amino-1,3-hydroxymethylbenzene (96) were synthesized and then reacted with trimethoxybenzene (92). No product was identified from the reaction of 91, but the chromium complex of 1,3-bis-(2 ′,4′,6′-trimethoxybenzyl) benzene (93) was obtained and fully characterized