Carbon−Hydrogen Bond Functionalization using Removable Monodentate Directing Groups

Chapter 1: 3,5-Dimethylpyrazole was employed as a mono-dentate directing group for palladium-catalyzed ortho-sp2 C−H arylation with aryl iodides. The reaction shows good functional group tolerance and outstanding selectivity for mono-ortho-arylation. Ozonolysis of ortho-arylated arylpyrazoles gave acylated biphenylamines that were further arylated to afford unsymmetrically substituted 2,6-diarylacetanilides. Chapter 2: N-Aminopyridinium ylides were used as mono-dentate directing groups for copper-promoted C−H/N−H coupling of sp2 C−H bonds with pyrazoles, imidazoles, and sulfonamides. Reactions proceed in fluorinated alcohol solvents at elevated temperatures and require use of 1.3−3 equiv of copper(II) acetate. This appears to be the first method for copper-promoted C−H/N−H coupling directed by a removable monodentate auxiliary in absence of added ligands. Chapter 3: N-Aminopyridinium ylides are competent monodentate directing groups for cobalt-catalyzed annulation of sp2 C−H bonds with internal alkynes. Pyridine moiety in ylide serves as an internal oxidant and is cleaved during the reaction. The annulation reactions possess excellent compatibility with heterocyclic substrates, tolerating furan, thiophene, pyridine, pyrrole, pyrazole, and indole functionalities.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Houston

Year dc:date.issued

2020

Author dc:creator

• kwak, sehun

Advisor dc:contributor.advisor

• Daugulis, Olafs

Committee members dc:contributor.committeemember

• Gilbertson, Scott R.
• Cai, Chengzhi
• Chen, Tai-Yen
• Cuny, Gregory D.

• C-H bond activation
• monodentate directing group

Statement dc:rights

• The author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. UH Libraries has secured permission to reproduce any and all previously published materials contained in the work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s).

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/10657/10257

OAI identifier oai:identifier

oai:uh-ir.tdl.org:10657/10257