Aluminum Phosphinate and Phosphates of Salen Ligands

A new dealkylation reaction between organophosphate esters and Salen aluminum bromide compounds has been used to prepare three new aluminum salen compounds salen(^tBu)AlOP(O)Ph₂ (1) (salen = N,N‘-ethylenebis(3,5-di-tert-butylsalicylideneimine)), [(MeOH)Alsalen(^tBu){OMePO₂(O)}Alsalen(^tBu){OMePO₂(O)}Alsalen(^tBu)]Br (2), and [salpen(^tBu)AlO]₂[(BuO)₂PO]₂ (3) (salpen = N,N‘-propylenebis(3,5-di-tert-butylsalicylideneimine)). Compounds 1·MeOH, 2, and 3 were characterized by single-crystal X-ray diffraction. Compound 1 is the first example of a monomeric aluminum Schiff base phosphinate. Compound 2 is a cationic Salen aluminum phosphate, and compound 3 contains an aluminophosphate ring. This work is the first example of the intentional use of an aluminum-based dealkylation reaction to form new compounds.