The Preparation Of Metal Porphyrin Polymer Catalyst And Application In Cycloaddition

Propylene carbonate is an important pharmaceutical intermediates,mainly for the synthesis of dimethyl carbonate,diethyl carbonate and tenofovir.Tenofovir is the key intermediate of the antivirals of tenofovir disoproxil fumarate,which is widely used in the treatment of AIDS.The new version of "Chinese Pharmacopoeia" to propylene carbonate as pharmaceutical excipients,mainly used as a gelling agent,solvent and acid gas scavengers in the aspect of Preparation.It also Can be used for external preparations,the preparation of oral formulations.To overcome the disadvantage of low activity and difficulty of separation of the catalyst in this cycloaddition process.we developed metalloporphyrin-based organic polymers [M?Por?OP] offer excellent possibilities for the engineering of metalloporphyrin-derived heterogeneous catalyst by combining the both advantages of heterogeneous catalysts for their separation/recycling and homogenous catalysts for their higher activity.In this research,we reported a most convenient and simple method for rapidly and reproducibly obtaining?Por?OP by convenient condensation of pyrrole and terephthaldehyde in propanoic acid.Moreover,the M?Por?OP?M = Zn,Co;Scheme 1a?was readily achieved by direct metallation?Por?OP with the corresponding metal acetate.We use different characterization methods such as XPS?FT-IR to confirm the successfully synthesis of catalyst.The catalytic performance of the polymer M?Por?OP?M = Zn,Co?for cycloaddition of CO₂ to propylene oxide?PO?was systematically investigated,and it was demonstrated that the M?Por?OP is very active,selective,and stable,and could be easily separated from the reaction system and reused.Moreover,one of the unique advantages of the developed M?Por?OP?M = Zn,Co?catalyst is that it bears dense catalytic sites of metalloporphyrin covalently and highly-cross linked in the polymer matrixes,which is responsible for the formation of active,stable,recyclable,heterogeneous and insoluble catalysts in any commonly used reaction media.To the best of our knowledge,this is the first demonstration of metalloporphyrin-based organic polymers with facile synthetic method,showing excellent catalytic performance to chemical fixation of CO₂ with insoluble/recyclable nature.Under the optimal conditions,a propylene carbonate?PC?yield of 95% and turnover frequency?TOF?of 3183 molPC molZn-1 h-1 are obtained by using Zn?Por?OP catalyst with KI as co-catalyst.Moreover,Zn?Por?OP behaves as a heterogeneous catalyst and can be easily reused at least for six times.Fe₃O₄ magnetic nanoparticle and SiO₂ particles with super magnetism property and large surface area to volume ratios used as support to prepared the SiO₂@?Por?OP,Fe₃O₄@SiO₂@?Por?OP by convenient condensation.and show higher catalytic activity,more importantly,they are reused at least for eighteen times without significant loss of activity...