Exploration of mild and selective hydrozirconation reactions facilitated by zirconocene hydride catalysts generated in Situ.

Metal hydride reagents are widely used in organic synthesis for the reductive functionalization of π-systems. In recent decades, the surging cost of precious transition metals has prompted the search for alternative hydrometalation approaches, especially innovative methods using first-row and early transition metal catalysis. Analogously, the use of zirconium is appealing because it is earth-abundant, has low associated toxicity, and is often is less costly than late transition metals. We sought to (i) develop reaction conditions that facilitate the conversion of oxozirconocenes to ZrH catalysts using hydrosilanes and (ii) identitfy a mild strategy for the preparation of a ZrH catalyst using Cp2ZrCl2 as a precatalyst. After establishing a general platform for ZrH catalyst generation and its efficient turnover, we successfully showcased its application towards the reduction of carbonyl-containing substrates (ketones, aldehydes, enones, lactones). Then, we extended this manifold to achieve the catalytic partial reduction of 2° amides and the partial reductive transamination of 3° amides. These findings guided our later studies on the direct catalytic conversion of esters to imines and enamines. In addition to carbonyl reduction, we have utilized ZrH catalysis to achieve the catalytic partial hydrogenation of alkynes. Ongoing work expands this catalytic protocol to novel redox-economical transformations enabled by synergistic Zr/Pd catalysis, including unprecedented deoxygenative cross-couplings of carbonyl containing functional groups and strategies for alkyne hydroarylation.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Doctoral

Grantor

Baylor University.

Year dc:date.issued

2024

Author dc:creator

• Kehner, Rebecca A., 1998-

Advisor dc:contributor.advisor

• Romero, Liela.

• Zirconium.
• Zirconocene.
• Hydride.
• Catalysis.
• Reduction.
• Hydrogenation.
• Silane.
• Carbonyls.

Statement dc:rights

• Baylor University works are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. Contact libraryquestions@baylor.edu for inquiries about permission.

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/2104/13561

OAI identifier oai:identifier

oai:baylor-ir.tdl.org:2104/13561