Reactive main group metal complexes of the neutral NNNN macrocycle, Me₄TACD

Currently, there is considerable interest in introducing molecularly defined main group metal compounds as precursors and model complexes of homogeneous catalysts for various bond cleavage and forming transformations. With a focus on the NNNN macrocyclic ligand Me₄TACD (N,N',N'',N'''-tetramethyl-1,4,7,10-tetraazacyclododecane), this review summarizes the versatility of the ligand Me₄TACD for the stabilization of reactive main group s- and p-block (group 1, 2, 12-14) metals. Metal hydrides, hydrocarbyls and silyls are often monomeric and catalyze alkene hydrofunctionalisations. In contrast to the rich coordination chemistry of d- and f-block transition metals using a plethora of ligands, main group metals still leave room for new structures and reactivities, aligning with the current efforts to develop a systematic understanding in s- and p-block metal-ligand combinations.