"Synthetic and Mechanistic Investigations of Ruthenium Catalyzed Coupli" by Aldiyar Shakenov

Date of Award

Spring 2025

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

First Advisor

Chae Yi

Abstract

Transition-metal catalyzed C-N and C-C bond activation reactions are synthetically valuable reactions for selective and atom-economical synthesis of complex organic molecules. Catalytic reactions that involve activation of unreactive bonds are important for the stereoselective synthesis of molecular scaffolds from readily available substrates derived from bio-mass feedstock. Despite these advances, designing a broadly applicable catalytic method faces challenges of selectivity and harsh reaction conditions. A five coordinate Ru-H complex was found to be an effective catalyst for promoting the multicomponent deaminative coupling reaction of anilines, aldehydes and tertiary amines to selectively afford 2,3-disubstituted quinoline products. The scope of the reaction was expanded to enamines to generate 2,3,4-trisubstituted quinolines. We devised a stereoselective synthesis of (Z)-acrylic nitriles from the Ru-catalyzed coupling reaction of nitriles with unsaturated carbonyl compounds via C–C bond cleavage. Mechanistic studies revealed that the C-C bond cleavage step is the rate-determining step of the reaction mechanism. A tetranuclear Ru-H complex was found to be an effective catalyst for the hydrodeaminative coupling reaction of nitriles and amides to afford secondary amides. The inverted V-shaped Hammett plot revealed a change in reaction mechanism depending on the electronic environment of the nitrile substrate. We detected a catalytically relevant intermediate by generating a Ru-H species in situ. A tentative mechanism for the coupling reaction was proposed based on the experimental data which involves nucleophilic attack of amide on the nitrile substrate followed by amine hydrogenolysis.

Available for download on Tuesday, May 19, 2026

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