由氢醌与2-硝基卟啉直接合成2-氢醌卟啉的反应研究

Study on the Direct Synthesis of 2-Hydroquinon-2'-yl Porphyrin from 2-Nitroporphyrin and Hydroquinone

由氢醌与2-硝基-5,10,15,20-四苯基卟啉或其金属配合物(2-NO2MTPP)直接反应合成2-氢醌卟啉I,同时得到了另一产物II.通过MS,IR,1HNMR及2DNMR测定,确定I与II中的2-取代基分别为氢醌与半醌,两者为互变异构体,且II是生成I的前体.高温下,水与空气介入反应体系能明显提高反应速率及产率,此时氧气的介入是提高反应速率的关键,而水介入反应体系将导致较强的酸性环境,更有利于II异构为产物I.整个反应可能为单电子转移(SET)的自由基反应.

2-（Hydroquinon-2-yl）-5,10,15,20-tetraphenyl porphyrin and its metal complexes Ⅰ were synthesized by the direct reaction of 2-nitro-5,10,15,20-tetraphenyl porphyrin with neutral hydroquinone in 60%-80% yields. 2-Substituted porphyrin tautomers Ⅱ were also obtained as byproduct and characterized by MS, IR, ^1H NMR and 2D NMR as precursor and dynamic isomer of Ⅰ. In applications of water and O2 intrusion at high temperature, both the rate and the yield of the system were increased obviously. The O2 intrusion would be the key for the increase of the rate and the water intrusion would lead to the more acidic environment resulting in the isomerization of Ⅱ to Ⅰ. From these experiments it was concluded that single-electron transfer free radical reaction mechanism was involved in the reaction.