AMINOCARBENE COMPLEXES OF CHROMIUM .8. ACCESS TO THE PYRROLOINDOLE AND PYRROLOCHINOLINE FRAMEWORKS AND SYNTHESIS OF SUBSTITUTED LYCORANES

The use of alkynylaminocarbene complexes of chromium as starting mater ial for the synthesis of pyrroloindole, pyrrolochinoline, and azaacena phtylenone skeletons via cascade insertions of alkynes and CO followed by the rearrangement of zwitterionic intermediates was examined. Both the precursor complexes, synthesized from the appropriate functionali zed lactams, as well as their thermolysis products were obtained in sa tisfactory yields and could be fully characterized. This reaction was finally applied to the synthesis of substituted lycoranes, a result wh ich confirmed its general scope.