Enantioselective Synthesis of Cyclohepta[]indoles via Pd-Catalyzed Cyclopropane C(sp)-H Activation as a Key Step.

An enantioselective synthesis of functionalized cyclohepta[]indoles via Pd-catalyzed cyclopropane C-H activation followed by olefination and indole-vinylcyclopropane rearrangement is reported. The design of the chiral cyclopropane precursor was such that both enantiomeric cyclohepta[]indoles were accessed from a single compound exhibiting a "hidden" symmetry plane. The scope of the method was demonstrated by varying the substituents on the cyclopropane as well as on the heterocycle itself.