Synthesis and Iron Carbonyl Promoted Coupling Reactions of 7-(Aryloxy)norbornadienes.

摘要

Mitsunobu reactions of 3-hydroxyquadricyclane (1) with phenol and with p-cyanophenol produced the corresponding 3-aryloxyquadricyclanes (2a (72%) and 2b (39%), respectively). Palladium(II) promoted valence isomerization of 2a and 2b afforded the corresponding 7-aryloxynorbornadienes (3a (84%) and 3b (80%), respectively). The thermal reactions of 3a and of 3b with Fe(CO)5 and with Fe2(CO)9 were studied. With the exception of the thermal reaction of 3b with Fe(CO)5, each reaction afforded a cage dimer (4a and 4b, respectively) and a dimer ketone (5a and 5b, respectively) in low to moderate yields. Thermal reaction of 3b with Fe(CO)5 gave only traces of 4b and no dimer ketone; instead, the major reaction product was p-cyanophenol (36%). A control experiment established that the p-cyanophenol probably was formed unreacted 3b during oxidative workup of the reaction mixture with ferric chloride-acetone solution. Organic chemistry. (jes)