Substrate or Solvent‐Controlled Pd^II‐Catalyzed Regioselective Arylation of Quinolin‐4(1H)‐ones Using Diaryliodonium Salts: Facile Access to Benzoxocine and Aaptamine Analogues

Abstract

Regioselective C3, C5, and C8 arylation of quinolin-4(1H)-ones have been accomplished either by substrate-control or by tuning the reaction solvent. A variety of aryl(mesityl)iodonium triflates could smoothly deliver arylated products in good to excellent yields. Additionally, it offers great flexibility by arylating medicinally potent quinolone related heterocycles such as acridin-9(10H)-one, and phenanthridin-6(5H)-one under stan- [a]

Diaryliodoniums Salts as Coupling Partners for Transition-Metal Catalyzed C- and N-Arylation of Heteroarenes

“…The optimization studies revealed that both the efficiency of the arylation and the C4-regioselectivity were enhanced using diaryliodonium salts as the coupling partners. Very recently, Kumar and co-workers reported a site-selective palladium-catalyzed CH arylation of quinolin-4(1H)-ones using diaryliodonium Salts [81]. Driven by the design of substrate-controlled site-selective reactions, the authors described an elegant C3-, C5-and C8-selective arylation by the utilization of an intrinsic directing group (Scheme 15a) [82,83].…”

Synthesis and Evaluation of the Tetracyclic Ring-System of Isocryptolepine and Regioisomers for Antimalarial, Antiproliferative and Antimicrobial Activities

“…x FOR PEER REVIEW 4 of 22 the formation of compound 4a by a palladium-catalyzed arylation technique utilizing diaryliodinium salts [63]. To the best of our knowledge, these two preparations of pyridophenanthridine 4a remain the only descriptions in the literature.…”

Diaryliodonium Salts in Transition‐Metal‐Catalyzed Chelation‐Induced C(sp2/sp3)−H Arylations

“…Coordination of Pd(II) with oxygen atom facilitates the activation of C-8 proton forming five-membered intermediate . [51] Treatment of quinolin-4(1H)-ones with unsymmetrical iodonium triflate using 5 mol % Pd(OAc) 2 in acetic acid provided C-5 arylated product whereas the same reaction with 1-hydroxy-2-methylquinolin-4(1H)-one afforded C-8 arylated product in good yield. The C-5 arylation ensues through the oxidative addition of aryl iodonium salt in five-membered palladacycle A which undergoes reductive elimination to generate the desired product.…”

“…Coordination of Pd(II) with oxygen atom facilitates the activation of C-8 proton forming five-membered intermediate . [51] Treatment of quinolin-4(1H)-ones with unsymmetrical iodonium triflate using way by oxidative addition of aryliodonium salt followed by reductive elimination.…”