New advances in asymmetric catalytic conversion of olefins

Recently, Prof. Yifeng Chen's group in the School of Chemical and Molecular Engineering and the Fellinga Nobel Prize Scientists Joint Research Center of East China University of Science and Technology has made new progress in the field of asymmetric catalytic conversion of olefins. The research results were published in the German Journal of Applied Chemistry under the title of "Nickel-catalyzed enantioselective reduction of aminocarbonyl-alkylation of endoenes".

In recent years, transition metal-catalyzed intramolecular asymmetric bifunctionalized cyclization of olefins has become one of the most important methods to construct chiral ring skeletons. Among them, nickel-catalyzed asymmetric reductive bifunctionalization of olefins not only avoids the use of organometallic reagents, but also successfully introduces the C(sp3) coupling component, which is prone to β-H elimination side reactions in palladium-catalyzed systems, to one end of the olefin, thus attracting much attention.

At present, most studies have focused on electrophilic reagent-substituted telenes. In contrast, the construction of reactions with two consecutive chiral centers by the nickel-catalyzed asymmetric bifunctionalization strategy of endoenes still poses a great challenge at present. Possible reasons are the low reactivity of the endoene and the low affinity of the endoene with the nickel catalyst further hindering the cyclization step of the reaction, as well as the easy homolytic cleavage of the alkyl nickel intermediates after cyclization increasing the difficulty of regulating the diastereoselectivity of the reaction.

The transition metal-catalyzed enantioselective cyclization reaction of aminocarbonyl electrophilic reagents, as one of the important methods for the synthesis of chiral lactams, has received a lot of attention from chemists in recent years. Based on the research interest in the construction of multiple chiral centers by transition metal-catalyzed olefin asymmetric bifunctionalization reactions, Prof. Yifeng Chen's group has realized nickel-catalyzed asymmetric aminocarbonyl-alkylation of endoenes through further optimization of the chiral 8-quinoline imidazoline as the core backbone Quinim ligand developed by the group, which provides a class of convenient synthesis of γ-lactams containing consecutive chiral centers This provides a new, mild and efficient method for the convenient synthesis of γ-lactams with continuous chiral centers.

In addition, in collaboration with K. N. Houk's group at the University of California, Los Angeles (UCLA), the group performed DFT theoretical calculations on the role of Quinim ligands in the enantioselective decision step and the reaction mechanism. The theoretical calculations provide theoretical guidance for the reaction mechanism of nickel-catalyzed reductive coupling chemistry and the further design and development of Quinim chiral ligands.