Redox of ferrocene controlled asymmetric dehydrogenative Heck reaction via palladium-catalyzed dual C–H bond activation

Abstract

A novel strategy of dehydrogenative Heck reaction controlled by redox process of ferrocene has been developed. Commercially available chiral amino acid as ligand realized asymmetric dehydrogenative Heck reaction, leading to planar-chiral ferrocene derivatives with excellent enantioselectivity and in good to excellent yields (up to 99% ee and 98% yield).Scheme 1 Palladium-catalyzed direct alkenylation of N,N-dimethylaminomethylferrocene.

Asymmetric C(sp2)H Activation

“…Planar chirality of ferrocene could also be accessed by means of an asymmetric dehydrogenative Heck reaction as disclosed by Cui and Wu. [12] Once more the Pd/amino acid catalyst turned out to be efficient in enhancing highly stereoselective coupling of N,N-dimethylaminomethylferrocene and diverse terminal olefins. It is worth noting that this catalytic system does not require addition of an oxidant.…”

A Combined IM‐MS/DFT Study on [Pd(MPAA)]‐Catalyzed Enantioselective CH Activation: Relay of Chirality through a Rigid Framework

“…Here, arylboronic acids were used as the arylation agents and Boc‐Val‐OH was employed as the ligand, affording high enantioselectivity (90–99 % ee ) 9. The Pd/MPAA‐catalyzed enantioselective olefination of planar‐ferrocene was reported by the Wu group 10. Recently, Pd/MPAA catalysts were successfully applied to enantioselective CH iodination through kinetic resolution11 and the enantioselective CH arylation of cyclopropymethylamines 12.…”

Access to β‐Lactams by Enantioselective Palladium(0)‐Catalyzed C(sp3)H Alkylation

“…[1] Moreover, sulbactam is used as a b-lactamase inhibitor. A limiting factor of palladium(0)-catalyzed [14] asymmetric intramolecular CÀH functionalization is the ring size of the arising cyclic product allowing access to five-, [15] six-, [16] and seven-membered rings. Apart from the pharmacological importance, they are also reactive starting materials used, for instance, in ring-opening reactions.…”

“…Transition-metal-catalyzed CÀH bond functionalizations [9] could offer complementary strategies through uncommon disconnections. A limiting factor of palladium(0)-catalyzed [14] asymmetric intramolecular CÀH functionalization is the ring size of the arising cyclic product allowing access to five-, [15] six-, [16] and seven-membered rings. [11] Recently, b-lactams were obtained through N-directed palladium(II)-catalyzed CÀH functionalizations and formation of the classical CÀN bond.…”