| As an important class of versatile synthetic intermediates,sulfoxonium ylides can readily take part in cyclization,insertion and substitution reactions,and have thus been used in the synthesis of a wide variety of organic functional molecules.Meanwhile,transition metal-catalyzed C–H bond activation-carbene insertion reactions are emerging as an effective tool for the construction of new C–C and C–X(heteroatom)bonds in recent years.Based on the above mentioned background and with the aim to expand the application scope of sulfoxonium ylides,this dissertation designed and explored some coupling reactions of ?-carbonyl sulfoxonium ylides.The main content of this dissertation includes the following two aspects.First,the coupling reaction between ?-carbonyl sulfoxonium ylides and ?-carbonyl diazo compounds catalyzed by Rh(III)complex was studied.From this reaction,a series of naphthalenone-sulfoxonium ylide hybrid compounds with diversified structures were synthesized.Preliminary mechanistic studies indicated that the formation of the hybrid products might involve a cascade process including C–H bond activation of ?-carbonyl sulfoxonium ylide and carbene insertion with ?-carbonyl diazo compounds as the carbene precursor,followed by an intramolecular condensation/annulation.Second,the homo-coupling of ?-carbonyl sulfoxonium ylides and the cross-coupling of ?-carbonyl sulfoxonium ylides with ?-keto aldehydes under the catalysis of Cu(II)salt were studied.From these reactions,a wide variety of 1,2,4-tricarbonyl compounds were efficiently synthesized.Compared with literature methods,the new methods developed herein have notable features such as easily accessible starting materials,simple operation procedure and high yield.In summary,some coupling reactions of ?-carbonyl sulfoxonium ylides have been carried out in this dissertation.From these studies,novel methods for the synthesis of naphthalenone-sulfoxonium ylide hybrids and 1,2,4-tricarbonyl compounds have been established. |
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