Enantioselective Access to 3-Azabicyclo[3.1.0]hexanes by Cp<sup>x</sup>Rh<sup>III</sup> Catalyzed C–H Activation and Cp*Ir<sup>III</sup> Transfer Hydrogenation
Ouidad Lahtigui, Dan Forster, Coralie Duchemin, Nicolai Cramer
Abstract
Rigid saturated nitrogen-containing scaffolds such as 3-azabicyclo[3.1.0]hexanes are very important and frequently occurring motifs in biologically active compounds. We disclose a flexible two-step protocol for their efficient and selective access. A tailored CpxRhIII catalyst promotes alkenyl C–H functionalization of N-enoxysuccinimides engaging in rare cis-cyclopropanation of acrolein to access disubstituted cis-cyclopropanes in high enantio- and diastereoselectivity. Subsequently, in the presence of a broad range of primary amines, the dicarbonyl cis-cyclopropanes are efficiently and completely diastereoselectively cyclized by a Cp*IrIII catalyst via an iterative aminative transfer hydrogen to an exquisite set of substituted 3-azabicyclo[3.1.0]hexanes.