Copper(I)‐Catalyzed Conjugate Addition/Enantioselective Protonation with Selenols and α‐Substituted α,β‐Unsaturated Thioamides

An unprecedented regiodivergent palladium‐catalyzed carbonylation of aromatic alkenes has been developed. Utilizing commercially available Pd(CH3CN)2Cl2 in the presence of 1,1′‐ferrocenediyl‐bis(tert‐butyl(pyridin‐2‐yl)phosphine) ligand L8 diverse selenoesters are obtained in a straightforward manner. Key to success for the control of the regioselectivity of the carbonylation step is the concentration of the acidic co‐catalyst. This general protocol features wide functional group compatibility and good regioselectivity. Mechanistic studies suggest that the presence of stoichiometric amounts of acid changes the properties and coordination mode of the ligand leading to reversed regioselectivity.

Regiodivergent Carbonylation of Alkenes: Selective Palladium‐Catalyzed Synthesis of Linear and Branched Selenoesters

Cao,

Wang,

Neumann

et al. 2023

Copper(I)‐Catalyzed Asymmetric 1,4‐Hydroarsination of α,β‐Unsaturated Compounds

Xiao,

Cai,

Pan

et al. 2024

Herein, a copper(I)‐catalyzed asymmetric 1,4‐hydroarsination of β‐substituted α,β‐unsaturated esters is achieved in moderate to excellent yields with high to excellent enantioselectivity, based on the proposed nucleophilic [Cu]‐AsPh2 species. As for α‐substituted α,β‐unsaturated esters, a 1,4‐hydroarsination/enantioselective protonation event occurs smoothly in satisfying results. Furthermore, β‐substituted α,β‐unsaturated ketone, α,β‐unsaturated amide, and α,β‐unsaturated phosphine sulfide are well applied in the present catalytic system. Finally, some control experiments show that HAsPh2 is activated through coordination with the copper(I) catalyst and HAsPh2 exhibits inferior soft Lewis basicity to HPPh2 in the presence of a copper(I)‐bisphosphine complex.

Asymmetric Carbene Insertion into Se−S Bonds by Synergistic Rh(II)/Guanidine Catalysis Involving Chalcogen‐Bond Assistance

He,

Fu,

et al. 2024

The efficient construction of chalcogen‐atom‐based chiral compounds remains a challenge, despite the importance of organoselenium and organosulfur compounds in life and materials science. Chalcogen atoms can form net attractive interactions called chalcogen bonds, but it is an undeveloped tool to assist asymmetric catalysis. Herein, we report an enantioselective insertion platform to install a stereogenic center bearing selanyl and thiocyano functional groups. Our method operates by synergistic catalysis by a chiral guanidine and an achiral dirhodium complex in a three‐component or four‐component reaction, through Se‐S bond insertion into carbene species, competing successfully with the spontaneous racemic process and showing high regioselectivity. As elucidated by spectroscopic experiments and computational studies, a unique mechanism involving chalcogen as well as hydrogen bonding was established to account for the enantiocontrol. The high stereoselectivity holds for a broad array of selanylthiocyanatopropanoates, which showed excellent anti‐inflammatory toward IL‐1β and low cytotoxicity.