A series of 38 chiral ruthenium complexes containing cyclic(alkyl)(amino)carbene (CAAC) ligands with axial C–N chirality have been developed. By merging axial and central chirality, very high enantioselectivity (up to >99% ee) as well as good to high E-selectivity (up to 98%) were achieved in the asymmetric ring-opening cross-metathesis (AROCM) of various norbornene and cyclopropene derivatives. Furthermore, these catalysts are efficient in challenging asymmetric ring-closing ene-yne metathesis (ARCEYM), providing valuable enantioenriched building blocks (up to 90% ee). Mechanistic insights from density functional theory (DFT) calculations highlight the crucial role of axial chirality in CAAC ligands in governing both enantio- and diastereo-selectivity in the metathesis reaction.
Merging Central and Axial Chirality in Cyclic(alkyl)(amino)carbenes: The Keystone for High Enantioselectivities in Ru-Catalyzed Asymmetric Olefin Metathesis
Falivene, Laura;
2025
Abstract
A series of 38 chiral ruthenium complexes containing cyclic(alkyl)(amino)carbene (CAAC) ligands with axial C–N chirality have been developed. By merging axial and central chirality, very high enantioselectivity (up to >99% ee) as well as good to high E-selectivity (up to 98%) were achieved in the asymmetric ring-opening cross-metathesis (AROCM) of various norbornene and cyclopropene derivatives. Furthermore, these catalysts are efficient in challenging asymmetric ring-closing ene-yne metathesis (ARCEYM), providing valuable enantioenriched building blocks (up to 90% ee). Mechanistic insights from density functional theory (DFT) calculations highlight the crucial role of axial chirality in CAAC ligands in governing both enantio- and diastereo-selectivity in the metathesis reaction.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
