Biscarbene complexes from the reactions of O-ethyl lactim and 1-alkynyl Fischer carbene complexes of chromium and tungsten

A chromium biscarbene complex with an azabicyclo[3.2.0]heptene core from the reaction of O-ethyl lactim ∼(CH2)3-NC(OEt)∼ with 1-alkynyl Fischer carbene complex (OC)5CrC(OEt)CCPh underwent SiO2-promoted rearrangement, thermal annelation and stepwise oxidation under controlled conditions.