Thesis advisor: James P. Morken / This dissertation describes three methods towards the stereoselective synthesis of organoboronates, and their application towards pharmacological targets of interest. The first chapter describes the use of alkyl migrating groups and alkyl electrophiles in the synthesis of secondary boronic esters through a highly selective nickel-catalyzed three component conjunctive cross-coupling reaction. Products from this conjunctive cross-coupling reaction are then converted to two alkaloids through boron amination and annulation processes. The second chapter describes the platinum-catalyzed diastereoselective diboration of carbocyclic, heterocyclic, and bicyclic alkenes. This reaction proceeded under air and both a homogeneous and heterogeneous catalyst was employed. Application of this reaction towards synthesis of the nucleoside analog Aristeromycin is also described. The final chapter details the development of an inexpensive and easily synthesized chiral diazaborinine that provides stereoinduction across a wide range of concerted and stepwise cycloaddition processes, affording heterocyclic-boron containing products in high yield and selectivity. Transformations of resulting organoboronates are also described. / Thesis (PhD) — Boston College, 2022. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Thesis advisor: James P. Morken / This dissertation will present four main projects focused on stereoselective construction of borylated compounds as well as their applications in asymmetric syntheses. The first two projects describe the development of a catalytic conjunctive cross-coupling reaction. By merging three simple starting materials, an organolithium reagent, an organoboronate, and an organic electrophile, a synthetically valuable secondary boronate is furnished by the conjunctive cross-coupling in an efficient and enantioselective fashion. Next, this strategy is expanded to synthesize severely hindered tertiary boronates, a synthetic challenging but powerful building block to access a variety of quaternary stereocenters. The third project presents a platinum-catalyzed enantioselective diboration of alkenyl boronates to furnish a broad range of 1,1,2-tris(boronates) products. A deborylative alkylation of the 1,1,2-tris(boronates) leads to a variety of internal vicinal bis(boronates) with high diastereoselectivity. In the final chapter, a general and practical synthesis of alkenyl boronates via the boron-Wittig reaction is disclosed. Utilizing readily accessible geminal bis(boronates) and aldehydes, a broad range of disubstituted and trisubstituted alkenyl boronates are afforded with good yield and stereoselectivity. / Thesis (PhD) — Boston College, 2017. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Thesis advisor: James P. Morken / This dissertation details three main projects that focus on stereoselective synthesis of organoboron reagents and their application to total synthesis studies. The first chapter describes the development of an enantioselective palladium-catalyzed conjuntive cross-coupling of bis(alkenyl)borates to access chiral allylboron reagents. These reagents are of high synthetic value that is demonstrated through various applications. The second chapter describes the development of a diastereoselective amine-modified boron-Wittig reaction with ketone electrophiles to access trisubstituted alkenyl boronic esters. The synthetic utility of these trisubstituted alkenyl boronic esters is demonstrated through a novel palladium-catalyzed cross-coupling reaction. The third chapter encompassess studies toward the total synthesis of natural products amphidinolides C and F. It highlights the application of methods developed in the Morken laboratory in the context of challenging total synthesis. It also highlights the potential for newly developed conjunctive cross-coupling and boron-Wittig reactions to solve problems in total synthesis. / Thesis (PhD) — Boston College, 2020. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Thesis advisor: Marc M. Snapper / Thesis advisor: James J. Morken / This dissertation will present three main projects focusing on the catalytic enantioselective synthesis and stereospecific functionalization of tertiary alkylboronates. In the first project, acyl chlorides were incorporated as a new class of electrophile in conjunctive cross-coupling, from which, a variety of tertiary β-boryl amides were successfully synthesized with high enantioselectivity. The utility of the tertiary alkylboronates products was also demonstrated through several orthogonal functionalizations of the boronic ester group and amide groups. The project culminated in the enantioselective total synthesis of natural product (+)-adalinine that leveraged this newly developed methodology. In the second project, a conjunctive cross-coupling enabled ring closure was developed to synthesize tertiary alkylboronates residing on carbocyclic and heterocyclic scaffolds. A Phosphinooxazoline (Phox) ligand was identified as a non-expensive ligand that catalyzed the conjunctive cyclization reaction with high enantioselectivity. A Series of synthetically challenging enantimerically enriched spirocyclic and aryl bicyclic tertiary alkylboronates were efficiently generated using this method, and several cyclopentyl boronic esters with two continuous stereogenic centers were synthesized with high diastereoselectivity. In the third project, a Rh-catalyzed diboration reaction was successfully employed to diborate monosubstituted cyclobutenes with excellent enantioselectivity. The less sterically hindered secondary boronic ester units in the diboron products can be regioselectively functionalized using the newly developed tert-butyllithium activation-transmetallation strategy. As a result, a variety of stereochemically defined β-substituted cyclobutyl tertiary boronic esters were synthesized with high efficiency. / Thesis (PhD) — Boston College, 2024. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.