Relay Catalytic Synthesis Of N-containing Heterocyclic Compounds And Fluorenones

This thesis mainly includes the following three parts:Efficiency and environmental sustainability need to be addressed carefully when making a valuable target molecule over several distinct steps.The one-pot synthesis including cooperative,relay and sequential catalysis is widely considered to be an efficient approach in synthetic organic chemistry.One-pot operations such as domino,cascade,tandem and multi-component reactions are of immense significance in nature and chemical research.Relay catalysis as a part of catalytic strategies of the one-pot continuous reaction has become an important tool for synthetic chemists.Therefore,it is necessary to develop the new relay catalytic reaction by taking the characteristics of various types of catalysts.This chapter mainly introduces the application of relay catalysis in organic synthesis,and briefly reviews the examples of metal-metal,metal-organic and organic-organic relay systems in recent years.A catalytic formal [3 + 1]-annulation reaction between cyclopropane 1,1-diester and aromatic amine is developed based on the relay catalysis strategy.Lewis acid-catalyzed nucleophilic ring opening of cyclopropane 1,1-diester with aromatic amine and(hypo)iodite-catalyzed C-N bond formation are combined successfully in one reaction.For some cyclopropane 1,1-diesters containing an electron-rich aryl group,the obtained azetidines rearranged to tetrahydroquinolines under the catalysis of Lewis acid.This reaction offers a convenient method for the synthesis of some azetidines and tetrahydroquinolines.The synthesis of substituted fluorenones directly from benzaldehydes and aryl iodides via a Pd(II)-relay-catalyzed C(sp2)-H functionalization cascade using transient directing group is developed.The process consists of arylation of the ortho C-H bond of benzaldehydes and a second C-H functionalization via oxidative Heck reaction.