Copper-catalyzed S-X Bond Coupling Reactions Investigation

Late transition metal-catalyzed cross-coupling had been a powerful tool to construct organic molecule.In the past few decades,it catalyzed reactions have well development.Compare with Pd、Rh and Ni,Cu is an inexpensive metal and possess lower toxicity.Meanwhile,the construction of S-X bond has also been significantly developed in this field.As it well-known,sulfur structural organic molecules has been broadly applied in the areas of materials,pharmarceuticals,dyes and flavors.So,It is very important to develop more new methods or novel sulfur structural.My doctorate project focused on developing Cu-catalyzed S-X bond coupling reactions investigation.1.Self-decomposition Of CuⅡ-alkylperoxide Initiate Selective Cleavage of C-S Bond:Taking One Oxygen Atom From Sulfonyl Access to Sulfinates.We studied the coupling reaction of beta keto sulfone with alcohol in a copper catalyzed free radical process.The beta keto sulfone substrate is a new class of conjugated substances.We through the control experiment and DFT,put forward a new C-S bond breaking mode（O-O bond’ crack in CuⅡOOR is the key C-S bond homolysis）and reveal the internal principle of sulfone transform into sulfoxide by resonance.2.Copper-catalyzed aerobic oxidative reaction of sulfonyl hydrazides with alcohols:an Easy access to sulfinates.The reaction demonstrated an unprecedented Cu-catalyzed oxidative reaction of alcohols with aryl sulfonylhydrazides using oxygen as an oxidant.Excellent substrates compatibility of sulfonylhydrazides that react with alcohols for the direct synthesis of sulfinic esters with moderate to good yields.The mechanism has been investigated,and discloses that the transformation proceeds through sulfinic acid as an intermediate.This method not only enriched the content of sulfonyl hydrazide related conversions,but also provides a new access to sulfinic esters.3.Cu-catalyzed deoxygenative C2-sulfonylation reaction of quinoline N-oxides with sodium sulfinate asymmetric.An unexpected Cu-catalyzed deoxygenative C2-sulfonylation reaction of quinoline N-oxides in the presence of K2S2O8 was developed.This reaction was carried out under mild conditions,which provides an easy pathway for the preparation of bioactive 2-sulfonyl quinolines with soldium sulfonate as a sulfonyl precursor.The mechanism studies indicate that the reaction proceeds via a Minisci-like radical-coupling step.Furthermore,the mechanic studies promote the discovery of conceptually new method proceeds reduce the quinoline N-oxide to quinolone without reduing agent.4.Copper-catalyzed selective aerobic oxidative cascade reaction of hydrazines,DABSO,and amines for the direct synthesis of sulfonamides.A Cu-catalyzed DABSO-based aerobic oxidative three-component coupling reaction of hydrazines and amines has been developed.The hydrazines were explored as new aryl precursors for the coupling reaction with DABSO and amines,affording the sulfonamides with good chemical yields.This highly selective reaction proceeds through the sequence of sulfur dioxide coupling with the aryl hydrazine and then coupling with an amine,resulting in sulfonamides,and no sulfonohydrazide products were detected.The cascade reaction was performed under mild conditions that proceeded without the use of any additional additives.This conceptually new method proceeds with the release of nitrogen,providing an easy and practical strategy for the preparation of sulfonamides.5.Cu-catalyzed oxythiolation initiated lactionization of unsaturated carboxylic acids with O₂ as oxidant and oxygenation reagent.A novel and efficient copper-mediated strategy for the synthesis of thio-substituted lactones through difunctionalization of alkenes.This reaction proceeds through an oxythiolation of C=C bond pathway with carboxyl as electrophilic group and dioxygen as reactant and oxidant.Furthermore,the mechanic studies promote the discovery of new strategies to construct substituted lactones based on unsaturated carboxylic acids through difunctionalization of alkenes.