Synthesis of nitrogen-containing heterocycles using nitro compounds as building blocks: Part I: Synthesis of 3-substituted azepanes. Part II: Synthesis of 1-azoniapropellanes as phase transfer catalysts

The chemistry of nitroalkenes and nitroalkanes has been explored with regard to synthesis of nitrogen-containing heterocycles, including 3-sustituted azepanes and 1-azoniapropellanes. A general synthesis of 3-sustituted azepanes has been developed using nitroalkenes as building blocks. A novel, vinylogous, conjugate addition reaction of an acylsilane-derived dienol ether to nitroalkenes was discovered. Reaction conditions were optimized for a number of -substituted nitroalkenes. Nitro acylsilanes as the conjugate adducts were obtained in good to moderate yield. Nitro acylsilanes were converted to the corresponding enals through a photoinduced protodesilylation. Saturation of the olefinic portion of the enals and subsequent reductive aminations afforded the 3-sustituted azepanes, which were protected as N-tosylamides. Using this streamlined process, a number of 3-sustituted azepanes were obtained in good yield. Efficient synthesis of chiral, enantiopure 1-azoniapropellanes as phase transfer catalysts has been developed. In the first method, the tandem [4+2]/[3+2] cycloaddition of nitroalkene was applied as the key step, wherein a chiral, enantiopure vinyl ether, a nitroalkene and a vinyl ketone were rapidly assembled. The resulting enantiopure nitroso acetals were then elaborated into 1-azoniapropellanes. Four azoniapropellanes were prepared using this method. Another method was developed using the conjugate addition of nitroalkanes to Michael acceptors as the key strategy. Stereochemical control was achieved by the application of Corey-Itsuno reduction of the nitro diketone intermediate. Starting from nitromethane and -chloropropiophenone, rapid access to 2,8-diphenyl-1-azoniapropellane and 2,8,9-triphenyl-1-azoniapropellane was accomplished .

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2010

Author dc:creator

• Xie, Min

Contributors dc:contributor

• Denmark, Scott E.
• Katzenellenbogen, John A.
• White, M. Christina
• Suslick, Kenneth S.

• synthetic methods
• azepanes
• azoniapropellane

Statement dc:rights

• Copyright 2010 Min Xie

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/16534

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/16534