Gold catalyzed cycloisomerization of propargylic alcohols and acetates as synthetic strategies to N-heterocycles
Date of Issue2014
School of Physical and Mathematical Sciences
This thesis will focus on the development of new methodologies utilizing propargylic alcohols and acetates in gold catalyzed strategies to potentially synthetically useful N-heterocycles. The protocols developed include tandem 1,3-migration/[2+2] cycloaddition of enantiopure 1,7-enyne benzoates in the presence of a gold(I) complex to form stereochemically well-defined azabicyclo[4.2.0]oct-5-enes and gold(I) catalyzed cycloisomerization and Diels-Alder reaction of 1,4,9-dienyne esters to 3a,6-methanoisoindole esters. In the course of our study on gold catalyzed reactions of propargylic alcohols, it was found that silver salts could also serve as a possible alternative to the third row metal as the catalyst to mediate the construction of indolin-3-ol derivatives via intramolecular hydroamination of 2-aminophenylprop-1-yn-3-ols. From this investigation, during examining the scope of the hydroamination reaction to include alkyl protected 2-aminophenylprop-1-yn-3-ols, an unexpected reaction leading to the formation of 2-oxindoles in the presence of silica gel is also presented.