Study On The Reaction Of Nonmetal Activated C(sp~3)-O Bond

Compounds containing carbon-oxygen single bonds widely exist in nature.Compared with the activation of carbon-halogen single bonds,the activation of carbon-oxygen single bonds does not require premodification of the substrate,and when the old carbon-oxygen single bonds are broken,oxygen can It is of great practical value to link with groups of practical value to generate specific molecules,and to regulate the activation of carbon-oxygen single bonds.However,due to the problem of low selectivity after the cleavage of the carbon-oxygen single bond,it is difficult to obtain specific molecules through the activation of the carbon-oxygen single bond.Therefore,the development of novel,efficient and highly selective carbon-oxygen single bond activation methods is one of the very difficult topics in organic synthesis.At present,more and more researchers use transition metal catalysts to activate carbon-oxygen single bonds.It is often necessary to carry out the activation reaction in an environment of high temperature and high pressure.To sum up,in this paper,ester bond,C(sp~3)-I bond and C(sp~3)-C(sp~3)bond are constructed mainly by transition metal-free activation of C(sp~3)-O bond reaction.The research content includes the following two parts:1)The model reaction uses tris(4-tolyl)boroxane and tetrahydrofuran as substrates,mediated by sodium trifluoromethanesulfinate,trifluoromethyltrimethylsilicon as the carbonyl source,and hydroxide Lithium and sodium iodide act together,and acetonitrile is used as solvent to activate the C(sp~3)-O bond of tetrahydrofuran.The main product is characterized by nuclear magnetic resonance spectroscopy and GC-MS,and its structure is determined to be4-iodobutane 4-methylbenzoate.Through literature search,it is confirmed that this is a brand new work,and a one-pot high-selectivity construction of ester bonds and C(sp~3)-I bonds has been achieved.After optimizing the reaction conditions of the model,a series of studies on the scope of the substrate were carried out.The results showed that aroyloxyalkyl iodide compounds were obtained in 42%-93%yields.Through the inductive analysis of the reaction results,the reaction mechanism and substrate applicability were discussed,and a series of applied studies on 4-iodobutyl 4-methylbenzoate were carried out.(2)The model reaction uses chromone as substrate and dimethyl sulfoxide as solvent,in the presence of cesium carbonate and sodium carbonate,the C(sp~3)-The O bond was activated,and the main product was characterized by nuclear magnetic resonance spectroscopy and GC-MS.The structure was determined to be cyclohexane-1,3,5-triyltris((2-hydroxyphenyl)methanone).This method realizes the one-pot high-selectivity construction of C(sp~3)-C(sp~3)bonds under mild and non-metallic conditions.After optimization of the model reaction conditions,a series of substrate applicability studies were performed,resulting in cyclohexane-1,3,5-triyltris((2-hydroxyphenyl))in good to excellent yields.ketones)compounds.Through the inductive analysis of the reaction results,the mechanism of the reaction and the applicability of the predicted substrate are discussed.