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 material for the synthesis of pyrroloindole, pyrrolochinoline, and azaacenaphtylenone 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 functionalized lactams, as well as their thermolysis products were obtained in satisfactory yields and could be fully characterized. This reaction was finally applied to the synthesis of substituted lycoranes, a result which confirmed its general scope.