N-heterocyclic Carbene-Catalyzed Formal [3+3] Annulation For The Construction Of Dihydropyridinones And Spirooxindoles

Organic catalysts have made remarkable achievements in the field of organic synthesis over the past decades,which allowing for the mild construction of complex molecules from simple starting materials,especially in the field of asymmetric organic synthesis.Among them Nheterocyclic carbene is highlighted,for it’s special ability to reverse the polarity of carbonyl carbon atom,which is named umpolung.Chapter 1: This chapter gives a brief introduction of N-heterocyclic carbene catalyst,including the progresses and emerging trends in this field.As an important role in the catalytic circle Breslow intermediate has been fully studyed by researchers.However,the acyl azolium,first reported decades ago,has now emerged as a central reactive intermediate for reaction discovery using N-heterocyclic carbene catalysis.The special reactivity of acyl cation has opened up a new avenue for organic synthesis and the application of N-heterocyclic carbenes catalysts.This chapter focuses on the production of various azolium and its application in organic synthesis.Chapter 2: The dihydropyridinone core is one of the characteristic structural motifs present in a variety of biologically active natural products and numerous pharmaceuticals to investigate the unprecedented [3+3] cycloaddition of enals and 2-aminoacrylates,we surveyed the commercially available cinnamaldehyde and N-tos-protected 2-aminoacrylate as the starting materials and quinone was used as the oxidant.Meanwhile modifying the standard base switched the carbon-carbon double bond transition from 5,6-positions to 3,4-positions to generate 5,6-dihydropyridinones and 5,6-dihydropyridinones,respectively.