Construction Of N-Containing Heterocyclic Compounds Via Photoredox Atom-Transfer Radical Cyclization Strategy

Visible light photocatalysis has been developed rapidly in modern organic synthesis in recent years due to its mild conditions and environmental friendliness.N-containing heterocyclic compounds are widely present in natural products and pharmaceutical molecules.Therefore,the efficient construction of these compounds has been one of the hotspots in synthetic methodologies.In view of this,we hope to use a photoredox atom-transfer radical cyclization strategy to synthesize N-containing heterocyclic compounds from readily available starting materials.This thesis is mainly incudes the following five parts.Chapter 1: Development of atom-transfer radical addition and cyclization reactions.Firstly,the development history and current research status of the atom-transfer radical addition(ATRA)reactions were briefly introduced.Then we summarized the atom-transfer radical cyclization(ATRC)reactions mediated by copper complexes.Finally,the research progresses of photoredox catalytic ATRA/ATRC reactions in recent years were reviewed.Chapter 2: Aroylchlorination of 1,6-dienes via a photoredox catalytic atom-transfer radical cyclization process.A method using aroyl chlorides as ATRC agents in a novel visible-light photocatalytic aroylchlorination reaction is developed.The overall transformation involves the formation of two new C–C bonds and one new C–Cl bond in a one-pot process.The advantages of this reaction include high atom/step/redox economy,mild conditions,operational simplicity,and broad substrate scopes.Chapter 3: A lutidine-promoted photoredox catalytic atom-transfer radical cyclization reaction for the synthesis of 4-bromo-3,3-dialkyl-octahydro-indol-2-ones.Reported herein is a visible‐light‐catalyzed photoredox ATRC halo-alkylation of 1,6-dienes with α-halo-ketones as the ATRC reagent.This process exhibits high atom economy,high step economy,and high redox economy,which can directly construct 4-bromo-3,3-dialkyl-octahydro-indol-2-one core under mild conditions in one pot,and lutidine is found to be the key promoter for this ATRC process.Chapter 4: Visible-light photocatalyzed brominedifluoroalkylation of 1,6-enyne.In this chapter,a multi-step tandem reaction of 1,6-enynes substrates with difluoroalkyl radical promoted by visible-light was developed.The Z-type olefin was synthesized with high chemical selectivity,and the double bond is outside the ring of five-membered N-containing heterocyclic derivatives.This reaction realized the photocatalytic 1,6-enynes brominedifluoroalkylation,with the advantages of higher yield,simple operation and mild conditions.Chapter 5: Highly selective 5-exo-trig radical cascade cyclization of 1,7-dienes visible-light photocatalysis for the synthesis of 2-oxindole derivatives.We developed highly selective 5-exo-trig radical cascade cyclization of 1,7-dienes by photoredox catalysis.A series of 2-oxindole derivatives containing 4-methyl-3-pentenyl fragments on N-atom were synthesized.This core was further derivatized to obtain a heptidinoindole tricyclic N-containing compound.