Investigation of transition metal-catalyzed ring opening reactions of bicyclic alkenes
This thesis is a two part investigation into the transition-metal catalyzed ring opening reactions of a 3-aza-2-oxabicyclo[2.2.1]hept-5-ene system. The first part of this thesis will investigate the ruthenium-catalyzed nucleophilic ring opening of a model - racemic 3-aza-2-oxabicyclo[2.2.1]hept-5-ene system with various alcoholic nucleophiles. Using a neutral ruthenium catalyst, Cp*RuCl(COD), ring opening lead to the formation 1,2-'trans' ring opened product in low to good yields (26-85 %) and excellent stereoselectivity (89:11 to 100:0). Using a cationic ruthenium catalyst, [CpRu(CH3CN) 3]PF6, the 1,2-'cis' ring opened product was obtained as the major isomer in low to moderate yields (0-72 %) with good stereoselectivity (70:30 to 100:0). In the second part of this thesis, the rhodium-catalyzed nucleophilic ring opening of a racemic 3-aza-2-oxabicyclo[2.2.1]hept-5-ene with arylboronic acids was investigated. Under the optimal conditions ring opening with substituted aryl boronic acids lead to a mixture of the 1,2-'trans' and 1,2-'cis' ring opened products. The corresponding ring opened products were obtained in moderate yields (39-68 %) with good selectivity (50:50 to 100:0).