Study On The Oxidation Of Benzyl Ether Sp~3 C-H Bond Catalyzed By Metalloporphyrin

Direct oxidation functionalization of benzyl C-H bonds is an important process for organic synthesis.In addition to being part of some natural products,the resulting oxygenates can also be used as a general-purpose material for the synthesis of specialty chemicals.The oxidation of many conventional methods of benzyl requires the use of large amounts of heavy metal oxidants,which can produce toxic and harmful by-products that can cause damage to the environment.In the context of the development of sustainable catalytic organic synthesis,the use of inexpensive and non-toxic oxygen as an oxidant has been the goal pursued by chemists.Despite significant improvements in the development of more sustainable oxidation methods,these strategies have some limitations,such as harsh reaction conditions,expensive catalysts,and complex process flows.In this paper,a 5,10,15,20-tetrakis?pentafluorophenyl?ferric chloride porphyrin(F₂₀TPPFeCl)was used as a catalyst,and N-hydroxyphthalimide?NHPI?was used as a promoter.O₂ is the catalytic oxidation system of oxidant,and the oxidation reaction of benzyl ether sp³ CH bond in this system is studied in depth.This paper consists of three parts:The first part of this thesis reviews the design,synthesis and application of metalloporphyrin catalysts in catalytic oxidation reactions,and summarizes the advantages of metalloporphyrins as effective biomimetic catalysts in catalyzing various oxidation reactions.The second part of this thesis mainly describes the catalytic oxidation of cyclic benzyl ether compounds by F₂₀TPPFeCl/NHPI/O₂ system.A series of heterochromatin derivatives were synthesized by two-step reaction using phenylethyl alcohol as a raw material by the method reported in the literature.The conditions were optimized by using heterochromatic full-molded substrate to obtain the optimal reaction conditions:0.2mmol%F₂₀TPPFeCl,0.1 mmol NHPI,35 ^oC,and stirred in air for 6 hours,the highest yield was 86%.Under the optimal conditions,we synthesized a series of heterochromatin derivatives and 1,3-dihydroisobenzofuran derivatives to synthesize the corresponding benzoic acid lactone derivatives with a yield of 36%⁹5%.Finally,through the mechanism experiment,the possible reaction mechanism is proposed.The third part of this thesis mainly describes the catalytic oxidation of open chain benzyl ether in F₂₀TPPFeCl/NHPI/O₂ system.The substrate application range of the catalytic oxidation system is further expanded.First,we synthesized a series of open-chain benzyl ethers by Williamson reaction and studied the oxidation under optimal conditions to synthesize a series of benzoate derivatives with a yield of 38%⁹3%.The experimental results show that the catalytic oxidation system has a wide range of substrate applicability,and the catalyst dosage is small,the oxidant is clean and environmentally friendly,and has good application prospects.