Research On The Synthesis Of A New Type Of Heterocyclic Borate (boronic Acid) Based On Iridium Catalyst

In recent years,with the development of the study of catalytic activity of transition metal,the use of iridium catalysis to synthesize boric acid compounds has become a hot spot for organic synthesis.Pyridine compounds are very active in chemical properties and can participate in a variety of electrophilic and nucleophilic reactions.Pyridine borate compounds are the preferred intermediates discovered in recent years.The Suzuki reaction of pyridine boronic acid compounds enables the docking of pyridine rings with other aromatic heterocycles under mild conditions.Therefore,the market demand for pyridine boric acid intermediate products is extremely huge,and the market prospect is broad.At present,the traditional method for preparing pyridine boronic acid compounds has the disadvantages of harsh reaction conditions,limited reaction substrates and uncontrollable substitution sites.Synthesis of novel heterocyclic boronic esters or boric acid(mainly pyridine rings)using iridium catalysts.This method does not require halogenated hydrocarbons on the pyridine ring and direct activation of C-H to prepare pyridine boronic acid compounds.Compared with traditional law,the route is simple and efficient,green and economic.In this paper,single element investigations were conducted on different boron sources,feed ratios,solvents,and temperatures.Determine the optimal reaction conditions and screen out the appropriate reaction substrate.Finally,15 compounds were synthesized,11 compounds without CAS number,1 compound with CAS number but no synthesis reports,and 3 compounds with process improvement.The structure of the target compound was confirmed by MS and ~1H NMR.After further research,it can realize industrialized production and has good economic value.