Studies On The One-Carbon Unit Transfer Reaction Of Benzimidazolium Salt And The New Methods For Biomimetic Synthesis

In living body, almost all the complicated and miraculous processes in mass-energy transformation are guided by enzymes. The processes carry on efficiently, especially and harmoniously in the soft environment. Since their particular properties of the enzymes in the various life activities have caused people strong interests in the biological phenomenon investigation, in recent years imitating the natural enzymes based on the molecule level has became a hot point in the biomimetic-chemical research field. The tetrahydrofolate(THF) coenzyme is the methyl source of the methylation for many materials (include the DNA and RNA) in the living body to transfer one carbon unit for the biosynthesis and metabolism. When the one-carbon unit is at the formic oxidation level, the structure research discovers that the active center of THF coenzyme is thought to be the unsymmetric imidazoline ring-stimulated, in which the different pKa of the two nitrogen atom is the nature of the active center. Imitating the structure, function and mechanism of the THF coenzyme to carry out the one-carbon unit transfer reaction in a biomimetic-chemical model may provide new reaction processes and synthetic methods for the organic synthesis.In this paper, we have studied a system of the 22 kinds of THF coenzyme models—benzimidazolium salt, which can transfer one carbon unit in the oxidation state of formaldehyde acid, reported the addition-hydrolysis reactions with Grignard reagent and nitrogen nucleophilic reagents to transfer the one-carbon unit, and provided new biomimetic-chemical synthetic methodes for 39 types of aldehyde, ketone and amide. As we know, aldehyde, ketone and amide are very important organic compounds. Because of their special structures, though the methodes about their syntheses are still expanded, the research for the new synthetic method is still a challenge field in the organic chemistry. In addition, in this paper we have also carried out a study of the benzimidazolium reduction-hydrolysis reaction, and have reported a new synthetic method of 9 kinds of aldehyde, di-aldehyde. The main contents of our research in this paper have been summarized as following three aspects:(1) the new synthetic method of aldehydeSelected two kinds of 1,3-methyl-substituted and benzyl-substituted benzimidazolium salt as tetrahydrofolate coenzymes models. The one-carbon unit transfer reaction is carried out through the nucleophilic reaction with Grignard reagent and di-Grignard reagent, and then hydrolysis to form aldehyde, provided new synthetic method for nine kinds of aldehyde and di-aldehyde. Based on this, using the reduction-hydrolysis reaction of benzimidazolium provided a new synthesize method for 6 types of aldehyde and three types of di-aldehyde. Meanwhile, we have discussed the experiment conditions, structures and other influence factors of these two synthetic methods, and also compared their adaptabilities of these two types of synthetic method.(2) the new synthetic method of ketoneSelected 2- substituted benzimidazolium salt or containing a functional unit with protential reactive center as thtrahydrofolate coenzymes models. The one-carbon unit transfer reaction is carried out by reacting with Grignard reagent, provided new synthetic method for 5 class of 19 kinds of ketone, and the influence factors, for example, the reacting mechanism, the condition, etc. were discussed. The designed and synthesized 2-substituted benzimidazolium salts can be used for the synthesis of macrocyclic ketone by intramolecular one carbon unit transfer, which is the soul of the new synthetic method. A series of one carbon unit transfer reactions is carried out by the combined reactions of the benzimidazolium salt or bisbenzimidazolium salt with Grignard reagent or di-Grignard reagent, which provides a new synthetic method for many ketones.(3) the new synthetic method of the amideOn the basis of the addition-hydrolysis reaction of benzimidazolium salt with Grignard reagent, we systemically studied the one carbon unit transfer reaction of benzimidazolium salt with the other nucleophilic reagent, amine compounds, and provided a new method of biomimetric synthesis for 8 kinds of amide compounds and 2-methyl- benzimidazolium compounds. Meanwhile, the structures of the synthesized compounds have been determined by ¹H NMR, ¹³C NMR, IR, elemental analysis and MS.The one carbon unit transfer reaction involving in the tetrahydrofolate coenzymes has caused great interest which is very important in the living system and has played an important role in the designing and syntheses compounds (especially the anti-cancer and LCD materials). In our study it was found that benzimidazolium salt has the ability to transfer one or two one-carbon unit and is a kind of new tetrahydrofolate coenzymes model. This research provides new method for biomimetic synthesis.