Native carboxyl group-assisted C–H acetoxylation of hydrocinnamic and phenylacetic acids

Abstract

Exogenous-directing-group free C–H acetoxylation of hydrocinnamic and phenylacetic acid derivatives is reported.

Ligand-Enabled C–H Hydroxylation with Aqueous H2O2at Room Temperature

“…Various strategies ranging from photocatalytic methods , to nickel, manganese, copper, and iron , catalysis have been explored to achieve aromatic C–H oxidations. Recently, palladium catalysis has emerged as a powerful strategy for selective oxygenation of C–H bonds. , The C–H hydroxylation reactions of arenes bearing strongly coordinating directing groups such as pyridyl or oxime have been reported using various oxidants; − however, these substrates are not practical for the synthesis. There are a handful of examples on C­(sp 2 )–H oxidation directed by weakly coordinating native directing groups such as free carboxylic acids using hypervalent iodine reagents such as PhI­(OAc) 2 , and an additional hydrolysis step is required to access the final phenolic compound (Scheme b). , …”

Mono and di ortho-C–H acetoxylation of 2-aryloxyquinoline-3-carbaldehydes

“…Using the directing group (DG) strategy, a number of C–O bond-forming reactions have been reported in recent years. 5 Among the various C–O bond-forming reactions, the acetoxylation of aromatic compounds is important. Furthermore, acetoxylation of aromatic compounds is essential since they can be easily converted into phenolic derivatives which are an integral part of many natural products and biologically active molecules.…”