Date of Publication

11-2019

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Chemistry

Subject Categories

Chemistry

College

College of Science

Department/Unit

Chemistry

Thesis Adviser

Glenn V. Alea

Defense Panel Chair

Jaime Raul O. Janairo

Defense Panel Member

Armando Victor M. Guidote, Jr.
Derrick Ethelbert C. Yu
Drexel H. Camacho
Francisco C. Franco, Jr.

Abstract/Summary

The Brønsted acidity of graphene oxide (GO) materials has shown promising activity in organic synthesis. However, the roles and functionality of Lewis acid sites remain elusive. Herein, we report a carbocatalytic approach utilizing both Brønsted and Lewis acid sites in GOs as heterogeneous promoters in a series of multicomponent synthesis of triazoloquinazolinone compounds. The GOs possessing the highest degree of oxidation, also having the highest amounts of Lewis acid sites, enable optimal yields (up to 95%) under mild and non-toxic reaction conditions (85oC in EtOH). The results of FT-IR spectroscopy, temperature-programmed decomposition mass spectrometry, and X-ray photoelectron spectroscopy identified that the apparent Lewis acidity via basal plane epoxide ring-opening, on top of the saturated Brønsted acidic carboxylic groups, is responsible for the enhanced carbocatalytic activities involving Knoevenagel condensation pathway. Recycled GO can be effectively regenerated to reach 97% activity of fresh GO, supporting the recognition of GO as pseudocatalyst in organic synthesis.

Abstract Format

html

Language

English

Format

Electronic

Accession Number

CDTG007971

Keywords

Graphite; Organic compounds—Synthesis

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Embargo Period

1-10-2023

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