Selective Cyclopropanation/Aziridination of Olefins Catalyzed by Bis(pyrazolyl)borate Cu(I) Complexes

Abstract

Bis(pyrazolyl)borate complexes [BBN(pz R ) 2 ]Cu(I) were evaluated as catalysts in the reaction of carbene/nitrene transfer and addition to C=C bonds of a wide range of aromatic, heterocyclic and aliphatic olefins. The complexes exhibit high catalytic efficiency and selectivity in both processes.

Recent advances in the accessibility, synthetic utility, and biological applications of aziridines

“…Indeed, a lot of pathways have been described by using different catalysts. 9 Among them, nickel was employed and in 2022 Wu and co-workers reported a nickel-catalyzed aminofluoroalkylative cyclization of unactive alkenes (15) with iododifluoromethyl ketones (14) to afford versatile difluoroalkylated nitrogen-containing hetorocycles including aziridines (18), as shown in Scheme 4. 10 According to the authors, the transformation proceeds through a radical mechanism.…”

“…Organic & Biomolecular Chemistry mediates such as 16, which react with N-allyl anilines (15) to give radical species 17, from which the aziridine products (18) are obtained. Berhal et al documented the iron-catalyzed reaction between alkenes (20) and hydroxylamine derivatives (19) to give aziridines 22.…”

“…During the catalytic process, a nitrene is generated and added to the double bond. 15 Dauban et al employed C4-symmetrical dirhodium(II) tetracarboxylates (48) as catalysts for the asymmetric intermolecular aziridination of substituted alkenes (47) with p-tBuphenylsulfamates 49 (TBPhsNH 2 ) (Scheme 8). The authors proposed a two-spin-state mechanism, involving a triplet Rhnitrene species as the key intermediate (50) to direct the approach with stereocontrol and for the activation of the substrate.…”