The Intramolecular [4+2] Reactions:A Theoretical Study

The Diels-Alder reactions continue to play a prominent role in synthesis,with which multiple rings can be created in one step with defined stereochemistry.In this project,we used theoretical calculations to study the side chain and substituent effect of intramolecular Diels-Alder reactions.A detailed literature survey was conducted on the intramolecular [4+2] cycloaddition reaction.This classic reaction has been employed in syntheses of manynatural products.It showed great potential in bioorthogonal chemistry and material chemistry.It have been successful in introducing functional groups on to nanotubes.There is no significant difference between the intramolecular cycloaddition reaction and the intermolecular cycloaddition;but due to the differences in entropy change,and tether effect on stereoselectivity,intramolecular cycloaddition is special,so we want to conduct a more in-depth exploration of the intramolecular Diels-Alder through theoretical calculations.Based on the literature research,two ctaegories of substrates were chosen alkenes and alkynes,to investigate the subsituent effects on molecular conformation.The transition state of intramolecular Diels-Alder reactions were studied in details.Through theoretical calculations,it is found that the intramolecular reaction of terminated acetylene is lower than that of alkene,and the addition product is more stable,and the steric hindrance of the substituents has a greater effect on stereoselectivity than the electronic effect.