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New Synthetic Applications of Boronic Acid Catalysis for Alcohol Activation
- Author / Creator
- Yakiwchuk, Joshua
Organic chemistry has its foundations in the 19th century; since, it has grown into a number of industries affecting our daily lives such as the manufacture of goods and life saving pharmaceuticals. The need for new and increasingly efficient synthetic methods has grown in response to the consumerism and industry of the 20th century. Some of the existing methods in synthetic organic chemistry are inefficient processes despite the explosive development over the last 60 years. Currently, there is a search for new, mild and efficient methods to produce common chemical functionality found in many of the goods and drugs used by people every day.
Arylboronic acids are a modular and stable class of compounds and may provide an answer to the replacement of some classical synthetic protocols. Boronic acids in general have an affinity for oxygen acting as Lewis acids through alcohol activation. This thesis investigates boronic acids as viable alternatives to classical catalysts and reagents using alcohols, a ubiquitous functional group, as substrates.
Elimination of alcohols has been a difficult task in organic chemistry for nearly a century requiring harsh conditions and stoichiometric activating agents. Transformation of an inexpensive alcohol, especially a primary alcohol, to an alkene in a mild and catalytic manner would simplify synthetic chemistry providing an alternative to what are harsh and toxic stoichiometric reactions. Chapter 2 will discuss investigations into the dehydrative elimination of alcohols.
Amide bonds are a stable linkage found in all biological systems. Interest in their formation is founded in researching the effect of new peptides and various pharmaceuticals. It is useful to form these linkages in a mild and catalytic manner. Currently, amides are predominately formed by coupling a carboxylic acid with an amine using various coupling reagents and a few catalytic methods; an alternate disconnection such as an alcohol and a nitrile could provide an alternate pathway to synthesize this functionality. The Ritter reaction, an amide formed from an alcohol and a nitrile, lacks wide-spread adoption due to the lack of mild, efficient and general methods. Chapter 3 will discuss an attempt to develop a mild boronic acid catalyzed Ritter reaction.
The Friedel-Crafts alkylation is one of the oldest ways of making bonds with aryl compounds but still enjoys widespread use to this day. Unfortunately, despite the advancement over the last decade, the Friedel-Crafts reaction is still plagued by high temperatures, low functional group tolerance and excessive substrate waste. Chapter 4 will discuss the activation of free benzyl alcohols for the formation of diarylmethanes using Friedel-Crafts chemistry and a novel boronic acid catalyst.
- Graduation date
- Fall 2015
- Type of Item
- Master of Science
- This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.