Semester

Summer

Date of Graduation

2008

Document Type

Dissertation

Degree Type

PhD

College

Eberly College of Arts and Sciences

Department

Chemistry

Committee Chair

Kung K Wang

Abstract

A new synthetic pathway leading to buckybowls was developed via cascade cyclization reactions of benzannulated enyne-allenes. The convergent assembly of the benzannulated enediynyl propargylic alcohols and the efficient cascade cyclizations of the resulting enyne-allenes leading to polycyclic aromatic dibromides for subsequent palladium-catalyzed intramolecular arylation reactions are the key features of this synthetic pathway. Three new buckybowls with their structures confirmed by X-ray structure analyses were thus synthesized.;Polycyclic aromatic hydrocarbon bearing ten fused ring system was successfully synthesized by using diindeno-fused 4H-cyclopenta[ def]phenanthrene prepared from the thionyl chloride-induced cascade cyclization reactions of the corresponding enediynyl propargylic alcohols. Direct tandem Knoevenagel condensation and hydrogenation efficiently furnished the diketones as precursors of propargylic diols for cascade cyclizations. Only five steps were involved in producing aromatic dibromides or diiodides as precursors for the buckybowls containing more than 44 carbons of C 60.;The synthetic pathway to the twisted polycyclic aromatic hydrocarbons bearing 4,5-diphenylphenanthrene moeity via the Schmittel reaction was successfully adopted for the synthesis of C2-symmetrical homo-bi-dentate ligands. Demethylation followed by derivatization with camphorsulfonyl group could convert enantiomers of 4,5-di(4-methoxyphenyl)phenanthrene derivatives to the corresponding diastereomers, which are separable on silica column chromatography. Similarly, 4,5-di-(4-aminophenyl)phenanthrene was likewise synthesized.

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