One-pot ruthenium catalyzed synthesis of spiro[pyrrolidin-2-one] derivatives by a [2 + 2 + 1] cycloaddition of ketimines, carbon monoxide and ethyleneElectronic supplementary information (ESI) available: experimental details. See http://www.rsc.org/suppdata/cc/b0/b008290m/Dedicated to Prof. Ernst-Gottfried Jäger on the occasion of his 65th birthday.

Abstract

The reaction of chiral N,N′-bis(aryl)tetrahydropyrrolo-[2,1-c][1,4]oxazin e-3,4-diylidenediamines with carbon monoxide and ethylene in the presence of a catalytic amount of Ru₃(CO)₁₂ leads to the formation of spiro-lactams by a formal [2 + 2 + 1] cycloaddition reaction, whereas the imine double bond next to the oxazine nitrogen atom remains unreacted; the same spiro-lactams may be synthesized if iron carbonyl complexes of the N,N′-bis(aryl)tetrahydropyrrolo-[2,1-c][1,4]oxazin e-3,4-diylidenediamines are introduced as the starting compounds.