Abstract
| - The reaction of α,β-unsaturated imines with CO and alkenes in the presence of Ru3(CO)12 as acatalyst results in a three-component coupling reaction that gives α,α-disubstituted β,γ-unsaturatedγ-butyrolactams. The reaction proceeds via a two-step sequence involving the initial formation ofketone derivatives by catalytic carbonylation at the β-olefinic C−H bonds of α,β-unsaturated imines,followed by the (uncatalyzed) intramolecular nucleophilic attack of the imine nitrogen on the ketoniccarbon to generate a tetrahedral intermediate, which then undergoes a 1,2-ethyl migration. Thereaction of a cyclic unsaturated imine, derived from the reaction of (1R)-(−)-myrtenal with tert-butylamine, gives a β-aminocyclopentene derivative, which is formed by an aldol-type condensationof the initially formed ketone, indicating the initial formation of ethyl ketone.
|