Date of Award

5-2026

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry and Chemical Engineering

First Advisor

Norito Takenaka

Second Advisor

Nasri Nesnas

Third Advisor

Alan B. Brown

Fourth Advisor

Andrew G. Palmer

Abstract

The development of efficient, selective, and atom-economical methods for synthesizing complex molecular structures remains a critical concern for organic chemists. Secondary and tertiary alcohols are present in many pharmaceuticals, often showing biological activity. In this dissertation, new strategies were developed for the regioselective allenylation of aldehydes and ketones using isomerically pure propargyltrichlorosilane (>99%).

Propargyltrichloroilane reagents have been shown to add regioselectively to carbonyl electrophiles in the Lewis base catalysis system. However, to this day, its synthesis and distillation have remained elusive. Our group recently solved this issue, providing propargyltrichlorosilane in isomerically pure form. We therefore tested its addition to aldehydes, which provided good to excellent yields of α-allenic secondary alcohols, catalyzed by (S)-1,1’-biisoquinoline-N,N’-dioxide. Contrary to what is believed, that the narrower the chiral pocket, the better the selectivity, this method proved the direct opposite.  This result led to the investigation of 4,4’-disubstituted-1,1-biisoquinoline-N,N’-dioxides as chiral catalysts for the allenylation of aldehydes to improve the results. Even though it showed a positive potential, it was below our expectations.

Following that, we investigated the addition of propargyltrichlorosilane to ketones, catalyzed by rac-3,3’-bis(3,5-dimethylphenyl)-1,1’-biisoquinoline,-N,N’-dioxide. To our amazement, this catalyst sufficiently activated our nucleophile to facilitate its addition to several ketones, providing excellent yields in most cases.

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