Synthesis and Characterization of β ‐Diketiminate Aluminum Compounds and Their Use in the Ring‐Opening Polymerization of ε ‐Caprolactone

Four aluminum alkyl compounds, [CH{(CH 3 )CN‐2,4,6‐MeC 6 H 2 } 2 AlMe 2 ] ( 1 ), [CH{(CH 3 )CN‐2,4,6‐MeC 6 H 2 } 2 AlEt 2 ] ( 2 ), [CH{(CH 3 )CN‐2‐ i PrC 6 H 4 } 2 AlMe 2 ] ( 3 ), and [CH{(CH 3 )CN‐2‐ i PrC 6 H 4 } 2 AlEt 2 ] ( 4 ), bearing β ‐diketiminate ligands [CH{(Me)CN‐2,4,6‐MeC 6 H 2 }] 2 (L 1 H) and [CH{(Me)CN‐2‐ i PrC 6 H 4 }] 2 (L 2 H) were obtained from the reactions of trimethylaluminum, triethylaluminum with the corresponding β ‐diketiminate, respectively. All compounds were characterized by 1 H NMR and 13 C NMR spectroscopy, single‐crystal X‐ray structural analysis, and elemental analysis. Compounds 1 – 4 were found to catalyze the ring‐opening polymerization (ROP) of ε ‐caprolactone ( ε ‐CL) with good activity.