Switchable Diastereoselectivity Controlled Multi-component Reactions And Lewis Acid Catalyzed Multi-component Reactions Based On Active Ylides

Multi-component reactions (MCRs) attracted more and more attention in academic community for its highly efficient synthetic strategies for rapid construction of diverse and complex molecules due to their atom economy, flexibility, convergence and simplicity. Recently, we have developed a novel multi-component reaction based on trapping alcoholic oxonium or ammonium ylides. However, reaction still has limitation not only in diastereoselectivity control but also in diazo decomposition catalyst.In this dissertation, we mainly focused on the multi-component reactions and multi-component domino alcoholic oxonium or ammonium ylides trapping process. We have developed a controlled diastereoselectivity switch in cooperatively catalyzed three-component alcoholic oxonium aldol reaction. And we discovered a novel lewis acid InBr3catalyzed three-component reactions based on trapping alcoholic oxonium yield. Besides, we represent a novel one-pot three-component domino reaction of aryl diazo ketone.First, a highly switchable diastereoselectivity controlled three-component reaction of an aryl diazoacetate, an alcohol, and a β,γ-unsaturated a-ketoester has been achieved. A dual-metal cooperative catalysis strategy was applied to control each desired diastereomer. Rh/AgBF4or Rh/InBrs catalyst system provided erythro or threo diastereomer respectively. The reaction efficiently afforded an a, β-dihydroxyl acid derivative bearing adjacent quaternary centers in high yield and diastereoselectivity. To the best of our knowledge, this is the first example in a three-component reaction of a remarkable diastereoselectivity switch being realized just by applying a different co-catalytic system.In addition, a novel lewis acid InBr3promoted three-component reactions of an aryldiazoacetate, an alcohol, and an electron deficient carbonyl compound giving α,β-dihydroxyl acid derivatives in good yield with high diastereoselectivity was discovered. The reaction was proposed through a protic oxonium ylide trapping process. The reaction mechanism for the formation of the protic oxonium ylide via Lewis acid InBr3catalyzed diazo decomposition was suggested through a vinyl cationic intermediate.Besides, A Rh catalyzed highly diastereoselective three-component tandem Michael addition/cyclization reaction of diazoacetophenones with anilines and unsaturated ketoesters was developed. The reaction provided highly efficient access to multisubstituted and mutilchiral central pyrrolidines in high yield and diastereoselectivity. The newly generated pyrrolidines could be easily converted to2,3-dihydropyrrole and pyrrole derivatives.