Study On The Synthesis Of New Type Of [60] Fullerene Pyrrolidine Compounds

Fullerenes as novel carbon materials have attracted extensive attention over the past thirty years owing to their interesting“three-dimensional”all-carbon molecular structures.Among the known fullerenes,[60]fullerene(C₆₀)is the most representative and notable one as a result of its perfect symmetry,easy availability,and outstanding properties.However,the poor solubility of C₆₀ in polar organic solvents and water has blocked its application in many fields such as materials and life sciences.Therefore,chemical modification of C60 to produce fullerene derivatives with structural and functional diversities is very important.1,3-Dipolar cycloaddition reaction is one of the most used and successful methods to functionalize fullerenes.In this thesis,we mainly describe the ferric perchlorate-mediated one-step reaction of C₆₀ with arylmethanamines as well as the thermal reaction of C60 with aromatic aldehydes and arylmethanamines to afford the rare2,5-diaryl fulleropyrrolidines by the 1,3-dipolar cycloaddition pattern.Various reaction conditions such as reaction time,reaction temperature and reactant ratio have been screened to achieve the best product yields.In addition,all of new 2,5-diaryl fulleropyrrolidine derivatives have been fully characterized by their HRMS,¹H NMR,¹³C NMR,FT-IR,and UV-vis spectra.Finally,plausible reaction mechanisms for the formation of 2,5-diaryl fulleropyrrolidines are also suggested.Chapter ?:Literature reviewSome progress in the last five years on chemical modification of C₆₀ to prepare various functional fullerene derivatives has been summarized in this chapter,especially for the 1.3-dipolar cycloaddition reaction of C60.In addition,the design idea for our research is also put forward.Chapter ?:Synthesis and characterization of 2,5-diaryl fulleropyrrolidines promoted by ferric perchlorateA series of scarce N-unsubstituted 2,5-diaryl fulleropyrrolidines as cis isomers can be prepared via the facile one-step reaction of C₆₀ with N-unsubstituted arylmethan amines promoted by cheap and easily available ferric perchlorate.Nevertheless,the reaction of N-substituted arylmethanamines with C60 under the same conditions gives different experimental results.N-Methylbenzylamine forms N-methyl 2,5-diphenyl fulleropyrrolidine as a trans isomer,and N,N-dibenzylamine unexpectedly obtains the N-unsubstituted 2,5-diphenyl fulleropyrrolidine as a cis isomer.Intriguingly,high stereo selectivity for all 2,5-diaryl fulleropyrrolidines can be observed although both cis and trans isomers are possibly formed.N-Unsubstituted fulleropyrrolidine can be further converted to N-substituted fulleropyrrolidines under the assistance of an acid chloride or an isocyanate.A possible reaction pathway leading to 2,5-diaryl fulleropyrrolidines is also proposed.Chapter ?:Synthesis of 2,5-diaryl fulleropyrrolidines via thermal reaction of[60]fullerene with aromatic aldehydes and arylmethanaminesThermal reaction of [60]fullerene with various arylmethanamines in the presence of aromatic aldehydes under air conditions affords a series of rare 2,5-diaryl fulleropyrrolidines.Intriguingly,the obtained fulleropyrrolidines exhibit different stereoselectivity.N-unsubstituted arylmethanamines exclusively produce 2,5-diaryl fulleropyrrolidines as cis isomers,while N-substituted arylmethanamines with rare exceptions always give 2,5-diaryl fulleropyrrolidines as trans isomers.Theoretical calculations at the level of B3LYP/6-31G?d,p?are employed to elucidate the stereoselectivity of N-substituted 2,5-diaryl fulleropyrrolidines as trans isomers by investigating the transition-state structures of different cycloaddition pathways.