REACTION OF A TERT-BUTYL-SUBSTITUTED IRON(0) ALKYNYL(ETHOXY)CARBENE COMPLEX WITH DIMETHYLAMINE

Abstract

The reaction of [(3,3-dimethylbutynyl)ethoxymethylene]Fe(CO)(4) (1) with dimethylamine was investigated. [(3,3-Dimethylbutynyl)(dimethylamino)methylene]-Fe(CO)(4) (2) was formed in. 95% yield by substitution of the ethoxy group at -78 degrees C. Meanwhile, the eta(3)-(2-(tertbutylcarbonyl)vinyl)carbene complete (3) was produced at 25 degrees C in 96% yield through the Michael-type addition of dimethylamine and subsequent rearrangements. The alkynyl(amino)carbene complex 2 was further reacted with dimethylamine in acetonitrile at 25 degrees C to give the eta(3)-vinylcarbene complex: 4 analogous to 3. Under CO pressure 3 and 4 were converted slowly to (eta(4)-alpha-pyrone)-Fe(CO)(3) complexes 5 and 6.