Functionalized calix[4]pyrroles

Abstract
The synthesis and properties of a number of functionalized calix(4)pyrroles are described. To date, two generalized preparative approaches have been pursued. The first involves modifying the basic pyrrole-plus-ketone synthesis of calix(4)pyrrole by using modified precursors or by co-condensing more than one ketone with pyrrole. The second approach relies on the reaction of a pre-formed calix(4)pyrrole with an electrophile. In both cases, the resulting species can be subject to further manipulation. In this way a range of structures, including ones bearing ancillary recognition subunits, electro- or photochemical reporter groups, and/or water solubilizing substituents may be obtained. Solid supports bearing calix(4)pyrroles may also be produced in this way.