Sulfuryl Fluoride Promoted Elimination Reaction Of Oxime Hydroxyl

As one of important organic intermediates,oximes which could be easily and efficiently converted by hydroxylamination of carbonyl compounds,are widely used to prepare a series of nitrogen-containing compounds.Reagents with special structure are always essential to activate the reactivity of oximes to participate in some chemical reactions.Especially sulfuryl fluoride which containing S^?-F bond is an essential part of these special reagents.As a colorless,odourless and nonflammable gas under normal temperature and pressure,sulfuryl fluoride?SO₂F₂?has been widely used as broad-spectrum fumigant in the past 50 years.In recent years,it has attracted great attention in the field of organic synthesis because of its special structure.Especially since the new click chemistry of sulfonyl???fluoride exchange?Su FEx?reaction developed by professor Sharpless in2014,and the increased annual industrial scale of high-purity SO₂F₂ gas,it has set off a new upsurge in the field of organic synthesis that various chemical transformations by utilization of SO₂F₂.Although most of these reations have the advantages of mild conditions and simplified operation,only the substrates containing hydroxyl and amino groups,such as phenols and amines,could be transformed by using SO₂F₂ in the most of reports.There are only few reports about the transformation of oximes containing oxime hydroxyl group with sulfuryl fluoride so far.Due to expand the field of SO₂F₂-mediated chemical reactions,a series of oximes,including aldoximes,ketoximes and amidoximes,have been studied in this paper.The main contents are as follows:1?SO₂F₂ promoted the dehydration and cyanidation of aldoximesA novel SO₂F₂-promoted the dehydration and cyanidation of aldoximes was developed.The reaction system occurs with simplified operation,mild conditions,short reaction times and good practicability.Varieties of aldoximes,including aromatic,olefin,alkyne and aliphatic functional group modified aldoximes,proceeded in excellent to near quantitative yields to afford corresponding nitriles,demonstrating the great functional group compatibility and high efficiency of this protocol.It provides a feasible method for the preparation of nitriles.2?SO₂F₂ promoted the Beckmann rearrangement of ketoximesThe study further expanded the application of SO₂F₂ as a special promoter for the the transformation of oximes,which SO₂F₂ promoted Beckmann rearrangement of ketoximes to synthesis of amides.This protocol has the advantages of simplified operation,good substrate compatibility and high yield.In addition,it has been proved to be feasible that one-pot synthesis of amides from ketones,and the proposed mechanism of this SO₂F₂-promoted Beckmann rearrangement was studied and confirmed.This protocol provides a feasible methodology for the preparation of amides with biological activity.3?SO₂F₂ promoted the one-pot synthesis of cyanamides from nitrilesIn this study,the one pot synthesis process of cyanamides from corresponding nitriles and hydroxylamine was realized by using sulfuryl fluoride as a promoter.Nucleophilic addition of nitriles and hydroxylamine,and SO₂F₂ mediated Tiemann rearrangement of amidoximes were involved in this methodology,which occurs with mild conditions and good substrate compatibility.With ideal separation yields,a large number of nitriles can be converted into corresponding cyanamides,which can be effectively transformed to various chemical structures.This protocol was proved the practicability and provides an alternative synthesis strategy for the preparation of cyanamides.