Synthesis of pyridines via [4 + 2] cycloadditions of vinylallenes with azadienophiles

Pyridines are an important class of heterocycle with widespread applications. However, the efficient preparation of substituted pyridines remains a challenge in organic synthesis. This thesis describes new annulation strategies for the synthesis of highly substituted pyridines that involve [4 + 2] cycloadditions of vinylallenes with azadienophiles. Part II of this thesis describes a unimolecular, formal [2 + 2 + 2] cycloaddition strategy for the synthesis of tricyclic pyridines based on intramolecular propargylic ene/imino Diels-Alder reaction cascades. In this variant, unactivated oximino ethers and NN-dialkylhydrazones function as dienophiles in thermal Diels-Alder reactions. Part III of this thesis describes strategies for the synthesis of bicyclic and monocyclic 2-sulfonylpyrdines based on [4 + 2] cycloadditions of vinylallenes with tosyl cyanide. In addition, Part III discusses the synthetic elaboration of these 2- sulfonylpyridines via nucleophilic aromatic substitution reactions. Overall, annulation strategies based on [4 + 2] cycloadditions of vinylallenes with azadienophiles have been developed for the preparation of highly substituted pyridines in an efficient, convergent, and regioselective fashion.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Chemistry.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2015

Author dc:creator

• Hamzik, Philip J. (Philip Jonathan)

• Chemistry.

Statement dc:rights

• M.I.T. theses 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. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/101546

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/101546