Synthesis of Pyrroloindolines via N-Heterocyclic Carbene Catalyzed Dearomative Amidoacylation of Indole Derivatives

Synthesis of γ-Oxo-phosphonates via N-Heterocyclic Carbene-Catalyzed Acylphosphorylation of Alkenes

“…When cyclopropyl-containing alkene 2y was reacted with 1a and 3c under standard conditions, the ring-opened product 4ay was isolated in 56% yield, thereby indicating the involvement of intermediate Int1 . On the basis of our experimental observations, as well as previous studies, a plausible mechanism is proposed in Scheme B. Initially, the in situ generated Breslow enolate A undergoes SET with the oxime phosphonate, which generates the NHC-derived ketyl radical B and the phosphorus radical C after homolysis of the N–O bond.…”

“…N -Heterocyclic carbene (NHC) radical organocatalysis has recently emerged as a powerful platform for the invention of versatile transformations. − Because of the strong reducing capabilities of the Breslow enolate A , an interesting application of this chemistry is the oxidative generation of NHC-derived persistent ketyl radical B for subsequent coupling reactions (Scheme B). , Pioneering work by Ohmiya et al showcased the single-electron reduction of redox-active esters, which yielded alkyl radicals and enabled the synthesis of sterically hindered ketones from a wide range of aldehydes . Ongoing work by us and the Ohmiya, Li, and Ye groups has extended the application of this organocatalytic strategy to access valuable radicals, including fluoroalkyl radicals, aryl radicals, N radicals, and O radicals.…”