Nickel-Catalyzed Directed C6-Selective C–H Alkylation of 2-Pyridones with Dienes and Activated Alkenes

Abstract

A pyridine-directed, C6-selective nickel-catalyzed ring-contracting C-H alkylation of 2-pyridones with 1,5-cyclooctadiene (cod) has been developed. The reaction proceeds smoothly under external-ligand-free conditions and is accelerated uniquely by a KPO base. Preliminary mechanistic investigations with deuterium-labeled substrates and related reactions with some alkenes are also disclosed.

Solvent‐Controlled Rhodium‐Catalyzed C6‐Selective C−H Alkenylation and Alkylation of 2‐Pyridones with Acrylates

“…To date, the C3, C4, C5, and C6‐selective C−H functionalizations have been reported under various transition metal catalyses. Our group has also focused on the site‐selective C−H functionalization of 2‐pyridones and developed the C3‐selective alkylation and arylation, and C6‐selective alkylation, (hetero)arylation, and borylation . As part of this research project, we herein wish to report a Cp*Rh(III)‐catalyzed C6‐selective C−H coupling of 2‐pyridones with acrylates via pyridine‐directed C−H cleavage (Scheme ): the reaction in DMF efficiently occurs to deliver the corresponding C−H alkenylation products in good yields (left).…”

“…On the basis of our recent success in the Cp*Rh(III)‐catalyzed C−H activation and pyridine‐directed C6‐selective C−H functionalization of 2‐pyridones, we initially tested the reaction of N ‐(2‐pyridyl)‐2‐pyridone ( 1 a ) with ethyl acrylate ( 2 a ) in the presence of [Cp*RhCl 2 ] 2 catalyst (5 mol%), AgSbF 6 additive (20 mol%), and Cu(OAc) 2 ⋅ H 2 O oxidant (1.0 equiv) under atmospheric conditions (Table ). Whereas the reaction in 1,2‐dichloroethane (DCE), toluene, 1,4‐dioxane, CH 3 CN, THF, and 2,2,2‐trifluoroethanol (TFE) gave no coupling product (entries 1–6), the DMF solvent afforded the expected C6‐alkenylated product 3 aa in 40% yield (entry 7).…”

C–H Functionalization of Aromatic Amides

“…Thei soindolinone skeleton hasg ood biological activity andisanimportant drug intermediate.Recently, anew synthetic method for isoindolinoneswas reported in which the ortho-C-H bond of aromatic amides was regioselectively alkenylated with alkynesu nder catalysis by the transitionm etal Ru, andt he alkenylated products further underwent intramolecular cyclization (Scheme 50). [75] This new method of synthesizing isoindolinonesi se nvironmentally friendly,d oes not produce by-products,a nd the atomicu tilization rate reaches 100%. Awide scope of functional groups in the substrates is tolerated and the reactionf urnishes high yields.…”

Recentes Avanços Em Reações Orgânicas Catalisadas Por Níquel

“…Após obter as melhores condições reacionais, foi investigado o escopo de 2-piridonas metilenos foram testados, assim como alcenos simples terminais, mas nenhum produto de acoplamento foi detectado. 25 Experimentos controle com marcação isotópica de deutério de 77-d 1 e estireno-d 8 25 A ativação C-H catalisada por níquel, por um tempo, tornou-se limitada a hidrogênios ácidos. O grupo de Chatani desenvolveu um sistema bidentado quelado 26 onde é possível ativar hidrogênios não ácidos como está descrito no Esquema 22 (para simplificar o entendimento, as condições e os grupos que não estão envolvidos na etapa chave não foram demonstrados no esquema).…”