Pd‐Catalyzed ortho Selective C–H Acyloxylation and Hydroxylation of Pyridotriazoles

• Published in: European journal of organic chemistry Vol. 2019; no. 48; pp. 7874 - 7879
• Main Authors: Rawat, Deepa, Kumar, Rahul, Adimurthy, Subbarayappa
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 31.12.2019; Wiley Subscription Services, Inc
• Subjects: Acetates; Acylation; Aliphatic compounds; Carboxylic acids; Chemistry; Chemistry, Organic; Gram scale reaction; Hydroxylation; ortho C–H activation; ortho Hydroxylation; Oxidizing agents; Palladium; Pd catalysis; Physical Sciences; Pyridotriazole; Reagents; Ring opening; Science & Technology; Gram scale reaction; ACETANILIDES; Pyridotriazole; 6-HYDROXY-3-SUCCINOYL-PYRIDINE; ALKYNES; Pd catalysis; FUNCTIONALIZATION; WHOLE CELLS; DENITROGENATIVE TRANSANNULATION; ARYL; ORTHO-BENZOXYLATION; BOND ACETOXYLATION; DERIVATIVES; ortho C-H activation; ortho Hydroxylation
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.201901748

An efficient protocol for the palladium‐catalyzed direct ortho C–H acyloxylation of 3‐phenyl‐pyridotriazoles is described. The reaction was facilitated by PhI(OAc)2 (PIDA) as an oxidant and with carboxylic acids as acyloxylation reagents. The reaction is highly selective for mono acyloxylation of pyridotriazoles with various acids such as aliphatic, branched, and cyclic including adamantane carboxylic acids. When acetic anhydride was employed as acylation reagent, interesting 2‐oxo‐1‐phenyl‐1‐(pyridin‐2‐yl)propyl acetates were obtained through the ring opening of pyridotriazoles. The key strategy is the employment of pyridotriazoles as a modifiable heterocycle; acyloxylation followed by the hydrolysis in one pot to yield the potential drug intermediates [(2‐hydroxyphenyl)pyridin‐2‐yl]methanone in good yields. An efficient protocol for the palladium‐catalyzed direct ortho C–H acyloxylation of 3‐phenyl‐pyridotriazoles is described. The reaction was facilitated by PhI(OAc)2 (PIDA) as an oxidant and with carboxylic acids as acyloxylation reagents. The reaction is highly selective for mono acyloxylation of pyridotriazoles with various acids