Developement of dinuclear metal complex catalysts using thiacalix[4]arene as ligand

Abstract

Thiacalix[4]arenes (1), in which methylene bridges of calix[4]arenes (2) are replaced with sulfides, have revealed themselves to be not a simple substitute for the "classical" 2 but a new molecular scaffold with intrinsic characteristic features originating from the bridging sulfur. One of the most note worthy features of 1 and its derivatives is their coordination ability toward metal ions to form not only mono- but also polynuclear metal complexes by virtue of the heterogeneous coordination site. It implies us to design polynuclear metal complexes of thiacalix[4]arenes, which should be suitable for metal catalysts. Herein we report the synthesis and catalytic applications of dinuclear titanium(IV) complexes of 1 and stereocontrolled synthesis of dinuclear borane complexes of 3.