Synthesis and reactivity of ortho-carborane functionalized boron species.

Boron reagents are useful synthetic tools as they possess a vacant p orbital which can accept electrons. Chapters two and three include the use of highly electron withdrawing and bulky ortho-carborane substituents as Lewis acids for Frustrated Lewis Pair (FLP) chemistry. FLP chemistry is a three-component reaction that involves the use of a Lewis acid (LA), Lewis base (LB) and a substrate. This chemistry has been applied in bond activation reactions including H-H, and Si-H, and C-F activation. Chapter four includes an inverse in boron reactivity in accessing nucleophilic boryl anions that are extremely difficult to prepare and handle. This challenging pathway can revolutionize boron chemistry field beyond its current scope. In this work we used bulky ortho-carborane substituents to generate transient (bis-ortho-carboranyl)boryl anions via reduction pathways from their respective precursors. As the boryl anions are isoelectronic to carbenes, these boryl anions went under [4+1] cycloaddition reactions. Chapter five focusses on haloboration of unsaturated systems, specifically nitroalkenes. Hydroboration reactions using secondary boranes have been explored in depth, whereas haloborations reactions are much less studied due to the decomposition pathways and not being selective in nature. In this chapter, we have shown that the use of bis(1-methyl-ortho-carborane)bromo borane solely provides the 1,4-bromoborated products in reactions with nitroalkenes. There is a need and utility for the synthesis of more electrophilic boranes. Motivated by this, our lab is focused on preparing Lewis superacidic boranes. Chapter six involves the synthesis of stable triflato and triflimide substituted boron on complexes bearing two ortho-carboranes that are labile and can activate strong bonds. The experimental scales reveal that the synthesized compounds are strong Lewis acids that are supported by DFT calculations indicate they are Lewis superacids. Overall, this work advances the field of carborane boron chemistry in utilizing the compounds as electrophiles and nucleophiles. The applications include the bond activations and the use of boron reagents in organic synthesis.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Doctoral

Grantor

Baylor University.

Year dc:date.issued

2026

Author dc:creator

• Vashisth, Kanika, 1997-

Advisor dc:contributor.advisor

• Martin, Caleb D.

• Carborane chemistry.

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/2104/14710

OAI identifier oai:identifier

oai:baylor-ir.tdl.org:2104/14710