Solid-phase synthesis of cyclic polyamines

A method for the synthesis of cyclic polyamines based on solid-phase chemistry is shown. Linear polyamines are stepwise synthesized on solid support from the center by repetitive alkylations at benzylic N-atoms. Cyclizations at the resins were effected conventionally by direct intramolecular SN2 reactions between sulfonyl-protected terminal amino groups and primary alkyl bromides or by intramolecular Mitsunobu reactions between sulphonamides and primary alcohols. Particularly the latter transformation proved to be powerful for the construction of medium- as well as large-sized rings.