Nickel-Catalyzed Regiodivergent Acylzincation of Styrenes with Organozincs and CO

Transition metal-catalyzed carbometallation of unsaturated hydrocarbons constitutes one of the most efficient synthetic methodologies for the construction of C—C bond.Recently,the incorporation of organometallic reagent with the CO gas as a nucleophilic acyl synthon could enable the acylmetallation reaction,which greatly increases the horizon of carbometallation chemistry.Herein,we report a nickel-catalyzed regiodivergent acylzincation of o-cyano cinnamate ester and o-cyano styrene,in which the cyano moiety intramolecularly captures zinc intermediates to trigger the tandem cyclization process.This protocol features mild conditions,broad substrate scope and excellent functional group tolerance,thus affording a diverse array of highly functionalized carbocyclic compounds.

Enantioselective Synthesis ofα-Alkenylatedγ-Lactam Enabled by Ni-Catalyzed 1,4-Arylcarbamoylation of 1,3-Dienes

The facile construction of chiral quaternaryα-alkenylated pyrrolidinones is a long-term challenge in organic synthesis.The asymmetric difunctionalization of 1,3-dienes represents the most compelling tool for assembling alkenylated compounds by regioselective 1,2-or 1,4-difunctionalization.Nevertheless,the manipulation of unactivated 1,3-dienes to forge the quarternary stereogenic center still remains largely underdeveloped.Herein,we disclose a nickelcatalyzed asymmetric 1,4-arylcarbamoylation of unactivated 1,3-dienes tethered on carbamoyl fluoride with readily available arylboronic acids,providing rapid access to the enantioenrichedα-alkenylated pyrrolidinones bearing the quaternary stereogenic center in high yields with broad functional group tolerance.Moreover,this chiral ligand-controlled asymmetric transformation overcomes the intrinsic substrate control with a preexisting chiral center.

Nickel/Quinim Enabled Asymmetric Carbamoyl-Acylation of Unactivated Alkenes

Transition metal-catalyzed difunctionalization of tethered alkene has emerged as a prevailing tool for the expedient construction of synthetically valuable cyclic compounds.However,most efforts have been devoted to the reaction of styrene-type substrates due to their rigid scaffold and high reactivity.With respect to the difunctionalization of nonaromatic tethered olefin,especially the mono-substituted alkene,still remains largely underdeveloped.Herein,we disclose a nickel/Quinim complex and TBADT-cocatalyzed asymmetric carbamoyl-acylation of unactivated alkene tethered on nonaromatic carbamoyl chlorides with diverse aldehydes.The reaction exhibits broad substrate scope with good functional group tolerance,as well as high reaction efficiency and enantioselectivity.Both monosubstituted and 1,1-substituted alkenes can work well with either aliphatic or aromatic aldehydes under the current protocol,providing convenient access to an array of medicinally useful chiralγ-lactams derivatives bearing a convertible acyl functionality.This reaction showcases more application possibilities of the chiral Quinim ligand in the future asymmetric catalytic transformations.