Studies On The Heck Couplings Of Ethenesulfonyl Fluoride(ESF) And The Sulfuryl Fluoride Promoted Alcohols Oxidation

Sulfur???fluoride exchange?SuFEx?represents the latest and one of the most powerful reactions in click chemistry.SuFEx features the unusual stability of S^VI-F,and the extreme fidelity of its activation in a nucleophilic substitution event under appropriate reaction conditions.As the synthon and highly connective molecules of SuFEx,ethenesulfonyl fluoride?ESF?and sulfuryl fluoride?SO₂F₂?participated or mediated reactions and transformations are of great research significance.As an important part of SuFEx,2-substitued ethenesulfonyl fluorides possess exceptional reactivity as selectively addressable bis-electrophiles.In the first part of this article,a palladium-catalyzed fluorosulfonylvinylation reaction of organic iodides is described.Catalytic Pd?OAc?₂ with a stoichiometric amount of silver?I?trifluoroacetate enables the coupling process between either an?hetero?aryl or alkenyl iodide with ethenesulfonyl fluoride?ESF?.The method is demonstrated in the successful syntheses of eighty-eight otherwise difficult to access compounds,in up to99%yields,including the unprecedented 2-heteroarylethenesulfonyl fluorides and1,3-dienylsulfonyl fluorides.In the second part of this paper,a practical oxidative Heck reaction between organoboronic acids and ethenesulfonyl fluoride?ESF?is developed.Aryl-and heteroaryl-boronic acids react efficiently and stereoselectively with ESF in the presence of a catalytic amount of Pd?OAc?₂ and DDQ or AgNO₃ in AcOH to afford the corresponding E-isomer of?-arylethenesulfonyl fluoride products.The utility of this reaction is exemplified by an expanded scope of 47 examples including N-,O-,and S-containing heteroaromatics,demonstrated gram-scale operation without the requirement for strict anhydrous or oxygen-free conditions.Furthermore,this procedure discriminates against the formation of homo-coupling byproducts of arylboronic acids.In addition,the preparation the first aryl vinylsulfonate polymer,a material with functionalizable Michael acceptor sites,from a starting arylboronic acid is described.Aldehydes and ketones are ubiquitously utilized in the synthesis of a large variety of versatile pharmaceuticals,fine chemicals,vitamins,fragrances and materials.Therefore,the development of methods for selective oxidation of alcohols to aldehydes or ketones is of great importance in organic chemistry for both academic research and industrial chemical production.In the third part of this research,a highly practical method for selective oxidation of primary and secondary alcohols to their corresponding aldehydes or ketones was developed using SO2F2 as fluorosulfonation reagent to activate alcohols for oxidation employing DMSO as oxidant at room temperature.The polar solvent DMSO was succeeded to act as oxidant and solvent.The utility of this reaction is exemplified by an expanded scope of 68 examples including N-,O-,and S-containing heteroaromatics,alkenyl and alkynyl functional groups in up to 99%yields without the requirement of strictly anhydrous or oxygen-free conditions.