摘要:
Reactions of HOPhtBu(CH2)Pz {4,6-di-tert-butyl-2-(pyrazol-1-yl-methyl)phenol} or HOPhtBu(CH2)Pz(Me) {4,6-di-tert-butyl-2-(3,5-dimethylpyrazol-1-yl-methyl)phenol} with 1.1 equivalent of (MgBu2)-Bu-n in toluene gave the binuclear compounds ((BuMgOPhtBu)-Bu-n(CH2)Pz)(2) (1) or ((BuMgOPhtBu)-Bu-n(CH2)Pz(Me))(2) (2). Treatment of HOPhtBu(CH2)Pz or HOPhtBu(CH2)Pz(Me) with 1.1 equivalent of ZnEt2 in n-hexane yielded binuclear compounds (EtZnOPhtBu(CH2)Pz)(2) (3) and (EtZnOPhtBu(CH2)Pz(Me))(2) (4). Colourless crystals of (ClZnOPhtBu(CH2)Pz)(2) (5) were obtained via the recrystallisation of 3 from a concentrated dichloromethane solution at room temperature. Alternative route for the synthesis of 5 can be achieved via the reaction of HOPhtBu(CH2)Pz with 1.1 equivalent of n-butyllithium in diethylether followed by the treatment of 1.1 equivalent of ZnCl2 in tetrahydrofuran gave compound 5 as binuclear chloride complex. The compounds 2 and 5 were crystallographically characterised. The catalytic activities of 1-5 towards the ring opening polymerisation reactions of cyclic esters in the presence of benzyl alcohol were under investigation. (C) 2013 Elsevier B.V. All rights reserved.