Synthesis and structure of a new bulky bis­(alkoxide) ligand on a terphenyl platform

A new sterically bulky chelating bis­(alkoxide) ligand 3,3′-([1,1′:4′,1′′-terphen­yl]-2,2′′-di­yl)bis­(2,2,4,4-tetra­methyl­pentan-3-ol), (H(2)[OO](tBu)), was prepared in a two-step process as the di­chloro­methane monosolvate, C(36)H(50)O(2)·CH(2)Cl(2). The first step is a Suzuki–Miyaura coupling reaction between 2-bromo­phenyl­boronic acid and 1,4-di­iodo­benzene. The resulting 2,2′′-di­bromo-1,1′:4′,1′′-terphenyl was reacted with ( t )BuLi and hexa­methyl­acetone to obtain the desired product. The crystal structure of H(2)[OO](tBu) revealed an anti conformation of the [CPh(2)(OH)] fragments relative to the central phenyl. Furthermore, the hydroxyl groups point away from each other. Likely because of this anti–anti conformation, the attempts to synthesize first-row transition-metal complexes with H(2)[OO](tBu) were not successful.