1 research outputs found
<i>N</i>‑Benzoylbenzamidinate Complexes of Magnesium: Catalysts for the Ring-Opening Polymerization of ε‑Caprolactone and CO<sub>2</sub>/Epoxide Coupling
No full textA series of amidinate-based N,O-chelated
magnesium complexes [(<b>L</b><sup><b>1</b></sup>)<sub>2</sub>(THF)<sub>2</sub>Mg]
(<b>1</b>), [(<b>L</b><sup><b>2</b></sup>)<sub>2</sub>(THF)<sub>2</sub>Mg] (<b>2</b>), [(<b>L</b><sup><b>3</b></sup>)<sub>2</sub>(THF)<sub>2</sub>Mg] (<b>3</b>),
and [(<b>L</b><sup><b>4</b></sup>)<sub>2</sub>Mg] (<b>4</b>) were prepared by treating <i>N</i>-benzoyl-<i>N</i>′-arylbenzamidines (<b>L</b><sup><b>1</b>–<b>4</b></sup>H) with 0.5 equiv of di-<i>n</i>-butylmagnesium in THF. Analogous CH<sub>3</sub>CN-coordinated complexes
[(<b>L</b><sup><b>1</b></sup>)<sub>2</sub>(CH<sub>3</sub>CN)<sub>2</sub>Mg] (<b>5</b>) and [(<b>L</b><sup><b>3</b></sup>)<sub>2</sub>(CH<sub>3</sub>CN)<sub>2</sub>Mg] (<b>6</b>) were prepared in a similar way using CH<sub>3</sub>CN as
solvent. All of the compounds were characterized by <sup>1</sup>H/<sup>13</sup>C NMR spectroscopy, and the molecular structures of <b>1</b>, <b>2</b>, and <b>4</b>–<b>6</b> were further confirmed by single-crystal X-ray diffraction studies.
Complexes <b>1</b>, <b>2</b>, <b>5</b>, and <b>6</b> displayed good catalytic activity toward the ring-opening
polymerization (ROP) of ε-caprolactone. In addition, <b>1</b>, <b>5</b>, and <b>6</b> were also found to be excellent
catalysts for making cyclic carbonates from CO<sub>2</sub> and epoxides
in the presence of a cocatalyst, <i>n</i>-Bu<sub>4</sub>NBr
