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|Title:||The Triplex Diels-Alder Reaction: An Investigation of Enantioselectivity and Scope|
|Doctoral Committee Chair(s):||Schuster, Gary B.|
|Department / Program:||Chemistry|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||Part I. Enantioselective triplex Diels-Alder reaction. An investigation of the enantioselective triplex Diels-Alder reaction has been performed with optically active biaryl sensitizers, (-)1,1$\sp\prime$bis(2,4-dicyanonaphthalene) and (-)1,1$\sp\prime$bis(2,10-dicyanoanthracene). Irradiation of an optically active sensitizer in non-polar solvents containing substituted trans-$\beta$-methylstyrenes and cyclic dienes yielded endo (4+2) adducts with enantioselectivity up to 23%. Our report is the first observation of an enantioselective photochemical cycloaddition reaction which is catalyzed by a chiral sensitizer. The mechanistic investigation suggests the presence of diastereomeric exciplexes. The advantages and limitations of the reaction are discussed along with the results from the mechanistic study. (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI)
Part II. Triplex Diels-Alder reaction with acetylenic dienophiles. An investigation of triplex Diels-Alder reaction has been carried out with sensitizers, 1,4-dicyanonaphthalene or 2,6,9,10-tetracyanoanthracene. Irradiation of a sensitizer in non-polar solvents containing acetylenic dienophiles and dienes yielded cycloaddition products. Results showed that either (4+2) or (2+2) cycloadducts are formed depending on whether the diene is cyclic or acyclic. Through product and photophysical studies, the scope and limitations of triplex Diels-Alder reaction with acetylenic dienophiles were examined.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1992.
|Date Available in IDEALS:||2014-12-17|