Degree Type

Dissertation

Date of Award

2019

Degree Name

Doctor of Philosophy

Department

Chemistry

Major

Organic Chemistry

First Advisor

Levi . Stanley

Abstract

This thesis presents the efforts towards developing transition metal-catalyzed protocols for rapid functionalization of alkenes. These protocols include - 1) enantioselective, palladium-catalyzed conjugate additions of arylboronic acids to generate compounds containing bis-benzylic quaternary stereocenter; 2) nickel-catalyzed three-component alkene carboacylation via activation of amide C-N bonds; 3) palladium-catalyzed intermolecular, acylative Heck reaction using amides as acyl electrophiles.

Chapter II discusses a strategy to access cyclic ketones containing bis-benzylic quaternary stereocenters through enantioselective palladium-catalyzed conjugate additions of arylboronic acids to β-aryl β,β-disubstituted cyclic enones. The catalyst generated from palladium trifluoroacetate and a chiral, non-racemic (S)-4-tert-butyl-2-(2-pyridyl)oxazoline ligand allows conjugate addition of a wide range arylboronic acids to a variety of to β-aryl β,β-disubstituted cyclic enones to generate ketones containing bis-benzylic quaternary stereocenters in up to 92% yield and up to 93% ee. This protocol uses iterative addition strategy to minimize unproductive protodeboronation of arylboronic acid and leads to the formation of compounds containing bis-benzylic quaternary stereocenters.

Chapter III describes the nickel-catalyzed intermolecular alkene carboacylation via activation of amide C-N bonds. The developed method allows rapid functionalization of bicyclic alkenes with a variety of N-benzoyl, N-phenylbenzamides, and triarylboranes to synthesize ketone products in up to 91% yield. Preliminary mechanistic analysis of the method reveals that migratory insertion precedes transmetalation and that reductive elimination is likely the rate-limiting step.

Chapter IV discusses palladium-catalyzed intermolecular acylative Heck reaction using amides as acyl electrophiles. The catalyst generated from [Pd(allyl)Cl]2 and DPEphos promotes reaction between a wide range of N-aroylglutarimides and bicyclic alkenes to form alpha,beta-unsaturated ketones in moderate to high yields (25-82%). This work represents the first examples of transition metal-catalyzed intermolecular acylative Heck reaction using amides as acyl electrophiles.

Copyright Owner

Abhishek Ashok Kadam

Language

en

File Format

application/pdf

File Size

143 pages

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