Rhodium-Catalyzed
Diastereo- and Enantioselective
Tandem Spirocyclization/Reduction of 3‑Allenylindoles: Access
to Functionalized Vinylic Spiroindolines
posted on 2019-11-26, 14:44authored byChristian
P. Grugel, Bernhard Breit
A highly selective rhodium-catalyzed tandem spirocyclization/reduction
of 3-allenylindoles is reported. By employing a Hantzsch ester as
reductant, vinylic spiroindolines are obtained in excellent yields
as well as diastereo- and enantioselectivity. In addition, the reaction’s
synthetic utility is highlighted by broad functional group compatibility
and exemplified by a gram scale reaction with subsequent assorted
transformations.