Semester

Spring

Date of Graduation

2014

Document Type

Dissertation

Degree Type

PhD

College

Eberly College of Arts and Sciences

Department

Chemistry

Committee Chair

Xiaodong Shi

Committee Co-Chair

Peter M. Gannett

Committee Member

Jeffrey L. Petersen

Committee Member

Bjorn C. G. Soderberg

Committee Member

Kung K. Wang

Abstract

The 'click chemistry' which provides 1,4-disubstituted 1,2,3-triazoles has been reported in 2001. New method for highly funtionalized 1,2,3-triazole synthesis becomes very desirable along with the discovery of unique properties of this heterocyclic structure. Our group focused on the synthesis of functional 1,2,3-triazole for several years and new methodologies have been developed such as arylation, vinylation, propargylation and allenation. Besides the new methods are benefiting the field related to triazole functionalization, new reactivity of ligand-metal complexes was revealed.;A series of 1,2,3-triazole gold complexes were synthesized/characterized. This dissertation presents the results of research effort to explore the unique chemoselectivity and improved thermal stability that arises when triazole is introduced as a X-factor or secondary ligand. This effort successfully led to the efficient synthesis of traditionally challenging compounds. The benzotriazole modified gold(I) complex showed high reactivity toward propargyl ester/vinyl ether. Through a simple 3,3-rearrangement, allene derivatives, which were usually considered as intermediate in the gold(I) chemistry, were isolated as a major product. The treatment of allene derivatives with triazole gold complex showed no apparent decomposition of allene and confirmed the triazole-gold complex could selectively perform the pi-acidity toward C-C triple bond over allene. With this triazole modification, the thermal stability of the corresponding gold(I) complexes is significantly improved. Triazole-gold(I) facilitated alkyne hydroboration was accomplished at 80 °C, which is a temperature leads to serious complex decomposition of previous cationic gold(I) species. Moreover, 31P NMR proved the stability of triazole-gold complex toward the highly reductive reaction precursor (such as boronhydride). This new strategy enabled an efficient method for amine borane heterocyclic structures synthesis, which has been considerable investigated recently as a potential hydrogen storage material.

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