Synthesis of silyliminophenolate zirconium compounds and their catalytic activity over lactide/epoxide

Abstract

Silyliminophenolate precursors (1–4) were prepared by reactions between 3-aminopropyldiethoxymethysilane (3-APS) and salicylaldehyde, 3-methoxysalicylaldehyde, 4-hydroxysalicylaldehyde, and 5-bromosalicylaldehyde in 1:1 mole ratio in ethanol at room temperature, respectively. Then these precursors were used in the preparation of the following compounds. The Zr-compounds (SPIMP)2Zr2(OnPr)2O, (MeO-SPIMP)2Zr2(OnPr)2O, (HO-SPIMP)2Zr2(OnPr)2O, and (Br-SPIMP)2Zr2(OnPr)2O were prepared by reaction of zirconium (IV) propoxide with silyliminophenolate (SPIMPH), silyliminomethoxyphenolate (MeO-SPIMPH), silyliminohydroxyphenolate (HO-SPIMPH), and silyliminobromophenolate (Br-SPIMPH) in n-propanol, respectively. All these compounds (1–8) were characterized by 1H, 13C NMR, FTIR, mass spectroscopies, elemental, and thermogravimetric analyses. In order to see their (5–8) catalytic activity over lactides and epoxides these compounds were tested in polymerization of l-lactide (LLA) and 3-glycidyloxypropyltrimethoxysilane (GPTS) and were effective. Poly-LLA, poly-GPTS, and copolymer of LLA/GPTS were characterized by 1H, 13C NMR, DSC, TGA, MS and gel permeation chromatography (GPC).