Upper-rim calixarene phosphines consisting of multiple lower-rim OH functional groups: synthesis and characterisation

The synthetic approaches to mono-isopropoxytrihydroxycalix[4]arenes bearing two or three diphenylphosphino groups at the upper macrocycle rim were elaborated. Due to reactive hydroxyl groups at the lower rim capable of binding with silica gel surface, the calixarenes, especially the enantiomerically pure inherently chiral diphosphinocalixarene, are promissing ligands for creation of hybride organic–inorganic metallocomplexing catalysts of organic (asymmetric) reactions.