Additive Effects in Metal/Lewis Acid Cooperativity Assessed in a Tetrahedral Copper Hydrazine Complex Featuring an Appended Borane.

Within metal/ligand cooperative systems employing acidic groups, studies that empirically assess distance relationships are needed to maximize cooperative interactions with substrates. We report the formation of two Cu(I)-NH complexes using 1,4,7-triazacyclononane ligand frameworks bearing two -butyl groups and either a Lewis acidic trialkylborane or an inert alkyl group. Metal/Lewis acid cooperativity imparts heightened acidification of the hydrazine substrate and plays a key role in the release of substrate to a competitive Lewis acidic group.