Date of Award

Spring 2021

Document Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

Yi, Chae

Second Advisor

Gardinier, James

Third Advisor

Dockendorff, Christopher


Transition metal-catalyzed selective CH, CC and CN bond activation reactions represent a challenging and synthetically important field in organic chemistry. In particular, transition-metal catalytic unreactive bond activation protocols are applicable in various stereoselective and atom economical complex organic molecule synthesis. Recently, significant research efforts have been made for utilizing catalytic CH and CC bond cleavage methods in the further development of commercially valuable pharmaceuticals and agrochemicals. The well-defined cationic Ru–H complex was found to be an effective catalyst for mediating the coupling reaction of 1,2-disubstituted indoles with α,β-unsaturated aldehydes and ketones, in which the regioselective Cα–Cβ activation of the carbonyl substrates has been achieved in forming a series of 3-alkylindole products. The analogous coupling reaction of indoles with saturated aldehydes and ketones directly led to the Cα–Cβ cleavage of the carbonyl substrates in forming the 3-alkylindole derivatives. The cationic Ru–H complex was found to be an effective catalyst for the dehydrative C–H coupling reaction of phenols and aldehydes to form 2-alkylphenol products. The coupling reaction of phenols with branched aldehydes selectively formed 1,1-disubstituted benzofurans, while the analogous coupling reaction with salicylaldehydes yielded xanthene derivatives. The DFT calculations provided a detailed catalysis mechanism featuring an electrophilic aromatic substitution of the aldehyde followed by the hydrogenolysis of the hydroxy group. The calculations also revealed a mechanistic rationale for the strong electronic effect of the aldehyde substrates p-X-C6H4CHO (X = OMe, CF3). We also developed an innovative multi-component deaminative catalytic reaction to synthesize xanthene and bicyclic dioxo-core structures efficiently. This multi-component coupling method facilitates multiple bond-breaking and forming operations in a single reaction sequence to assemble synthetically valuable complex organic molecules.

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