As aluminium is the most abundant metal in the Earth's crust, various applications involving this metal are considered sustainable, including catalysis. As such our perennial aims have been to establish new directions in the field of Lewis acid catalysis through the creation of a unique set of aluminium compounds. Our recent work demonstrated that a β-diketiminate supported aluminium bistriflate complex activated by one equivalent of Na[BAr^Cl₄] (Ar^Cl =3,5-Cl₂C₆H₃), acts as a very reactive Lewis acid catalyst for polymerization of 2-cyclopenten-1-one, leading to the formation of poly(cyclopentenone) as a novel polymeric material. Altering Na[BAr^Cl₄] of the catalytic system to other Group 1 metal salts like Li[BAr^CF3₄] and K[BAr^CF3₄] (Ar^CF3 =3,5-(CF₃)₂C₆H₃) has been found to have negligible effect on the properties of the resulting polymeric material. Preliminary studies have shown that polymerization of 2-cyclohexen-1-one and 2-cyclohepten-1-one using the same catalytic system results in insoluble materials which limits further analysis. We herein report further studies and analysis related to these latter transformations as well as extension of the polymerization to analogous substrates like cyclobutenone, substituted cyclopentenones, 2-furanone and analogous cyclic diones. Further modifications of poly(cyclopentenone) have also been explored through modification of the carbonyl functional group to alcohols and imines; the properties of the resulting materials will be discussed.

Dragoslav Vidovic

Nanyang Technological University

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