Design And Synthesis Of New Bi-PCUD Cage Hydrocarbons And Related Derivatives

Cage hydrocarbon compounds have drawn more and more attention in many fields,mainly in the fields of fuels and medical.In the field of high-density hydrocarbon fuels,cage hydrocarbons were selected because of their inherent advantages such as high density and high volumetric heat of combustion.In the field of medical,many cage hydrocarbon compounds were selected because of their polycyclic structures.This thesis firstly summarized the synthesis of mono-cage hydrocarbons and bi-cage hydrocarbons.Based on this,new bi-cage hydrocarbons were designed and synthesized.(1)4,4’-bipentacyclo[5.4.0.02’6.03,10.05,9]undecane was designed and synthesized in 23%overall yield starting from p-benzoquinone and 5,5’-bi(cyclopentadiene)through Diels-Alder reaction,[2+2]photocyclization and Wolff-Kishner-Huang reduction.The structure of bi-cage hydrocarbon was confirmed by the crystal structure of 21,and two PCUDs were connected with C-C single bond.Compared with the PCUD alkene dimer 6a,4,4’-bipentacyclo[5.4.0.02,6.03,10.05,9]undecane had approximately the same density(1.2322 g/cm3)and higher volumetric heat of combustion(51.670 MJ/L).(2)4,4’-spirobi[pentacyclo[5.4.0.02,6.03,10.05,9]undecane]was designed and synthesized by a nine steps synthetic scheme starting from p-benzoquinone and diene 23 in 7%overall yield.The structure of bi-cage hydrocarbon was confirmed by the crystal structure of 34,and two PCUDs shared one spiro-carbon.Compared with the PCUD alkene dimer 6a,4,4’-spirobi[pentacyclo[5.4.0.02,6.03,10.05,9]undecane]had higher density(1.2663 g/cm3)and higher volumetric heat of combustion(53.353 MJ/L).(3)Based on the synthetic route of 4,4’-spirobi[pentacyclo[5.4.0.02,6.03,10.05,9]undecane],some derivatives were designed and synthesized starting from the Diels-Alder reaction of diene 23 and 32 with p-benzoquinone derivatives,which were mainly di-halogenated spiro-mono-cage and spiro-bi-cage hydrocarbon compounds.The bi-chlorinated and bi-brominated spiro-cage hydrocarbon compounds were synthesized through Diels-Alder reaction and[2+2]photocyclization.Bi-iodinated spiro-cage hydrocarbon compounds were synthesized from bi-brominated spiro-cage hydrocarbon compounds through Favorskii rearrangement and modified Hunsdiecker reaction.The investigation of Diels-Alder reaction of 23 with 2,5-dibromo-p-benzoquinone was performed,two isomers(39a:39b=20:1)were confirmed by the crystal structure analysis.Based on these,the calculation of this reaction was performed by DFT.The calculation confirmed that 39a was formed more favourable(both kinetically and thermodynamically)than 39b because 39a was more stable and had a lower barrier when formed transition state.