Rhodium‐Catalyzed Chemo‐, Regio‐ and Enantioselective Hydroformylation of Cyclopropyl‐Functionalized Trisubstituted Alkenes.

The first rhodium‐catalyzed highly chemo‐, regio‐ and enantioselective hydroformylation of cyclopropyl‐functionalized trisubstituted alkenes affording useful chiral cyclopropyl entities is reported. Compared to generally used diphosphine ligands for asymmetric catalysis, the modified hybrid phosphorus ligand, named (R,S)‐DTBM‐Yanphos, can convert a series of readily available cyclopropyl‐functionalized trisubstituted alkenes into high‐value chiral cyclopropyl‐functionalized aldehydes with high selectivities (81–98 % ee). Gram‐scale reactions (TON up to 1500) and follow‐up transformations to the corresponding alcohol, acid, esters and nitrile are also presented. Finally, a possible hydroformylation mechanism involving ring‐open‐hydroformylation pathways is proposed based on control and deuteroformylation reactions. [ABSTRACT FROM AUTHOR]