Palladium-Catalyzed Allenamide Carbopalladation/Allylation with Active Methine Compounds

Abstract

A palladium-catalyzed allenamide carbopalladation/ allylation with active methine compounds has been developed. Various indoles and isoquinolinones bearing a quaternary carbon center were achieved with good efficiency, a broad substrate scope and good functional group tolerance. This reaction underwent cascade oxidative addition, carbopalladation, and allylic alkylation, and two new C−C bonds were formed in one pot.

Recent Advances in the Synthesis of Five‐membered Nitrogen Heterocycles Induced by Palladium Ions and Complexes

“…Lin, Yao, and colleagues developed a different method upon treating 2-iodoallenamides 16 d with active methine compounds. [101] Varied indole derivatives with substituents at C-3 bearing a quaternary carbon center were synthesized applying Pd(PPh 3 ) 4 and diphenylmethanamine under mild conditions (Scheme 75). A range of other nucleophiles, including β-ketoester, malonate, 2-nitro-and 2-cyanopropionate, amide, ketone, were also reacted to give low to excellent yields of 43-93 % [Pd(PPh 3 ) 4 , Cs 2 CO 3 ].…”

Diversely functionalized isoquinolines and their core-embedded heterocyclic frameworks: a privileged scaffold for medicinal chemistry

“…52 Zhu et al developed a palladium catalysed cascade oxidative addition protocol for constructing isoquinolinone derivative 51 (Scheme 9). 53 The one-pot synthetic protocol involves the carbopalladation of allenamide 47 to form the isoquinolinone intermediate 50, followed by allylic alkylation with aldehyde 48 to afford isoquinolinones bearing a quaternary carbon core 51.…”

Substrate-Dependent Regioselectivity: Pd/PTC Cooperatively Catalyzed Domino Heck/Allylation of Allenamides with α-Carbon of Carbonyl Compounds

“…However, the domino Heck process based on enolate to capture C−Pd intermediates is rarely reported. Recently, Lin's group 14 reported palladium-catalyzed domino Heck/allylation of allenamide with active methine compounds to generate a single linear allylation product (Scheme 1b). Our group 15 has reported a new class of palladium-catalyzed asymmetric domino Heck cyclization/dearomatization reactions of βnaphthols with N- (2-iodophenyl)allenamides for the construction of indole-terpenoid analogs.…”