PHOTO-INDUCED THIOL COUPLING AND C-H ACTIVATION UNDER HETEROGENEOUS CONDITION AND ALKYLATION/ACYLATION UNDER HOMOGENEOUS CONDITION

Abstract

This thesis focused on organic transformations with heterogeneous semiconductor photocatalysts and homogenous organic photoredox catalysts, respectively. First, the utilization of cesium lead halide perovskites nanoparticles as photocatalyst was studied, which enabled the photocatalytic oxidative coupling of mercaptans. The coupling reactions selectively provided symmetric and unsymmetrical disulfide derivatives under visible light condition. Besides, the developed perovskite-catalytic system was further extended to the cross-dehydrogenative coupling between tertiary amines and phosphite esters, and offered good isolated yields of desired products. Additionally, the visible-light-mediated halide exchange process of cesium lead halide perovskite nanoparticles with different haloalkanes was also presented. Second, a metal-free reaction that introduced 9-mesityl-10-methylacridinium perchlorate as photocatalyst with blue LEDs allowed the selective alkylation and acylation of pyridine N-oxides with alkynes. This methodology successfully delivered different target molecules by only controlling the anaerobic and aerobic conditions. Mechanistic studies suggested that the acidic environment is essential to achieve high yields of products.