Synthesis of dinuclear boron complexes of sulfinylcalix[4]arenes: Syn/anti stereocontrol by the arrangement of the sulfinyl functions

(Chemical Equation Presented) Stereocontrol in the synthesis of dinuclear metal complexes of sulfinylcalix[4]arenes 2 has been achieved by the arrangement of sulfinyl functionalities. Thus, the treatment of the rtct isomer of 2 (2r_tct) with an excess of Et₃B affords syn dinuclear boron complex 4, while a similar treatment of rctt and rcct isomers 2_rctt and 2_rcct yields anti dinuclear complexes 5 and 6, respectively.