Oxidative cyclization of alkenoic acids promoted by AgOAc

Abstract

Alkenoic acids derived from salicylic acid and analogues undergo an unexpected oxidative cyclization process triggered by AgOAc leading to 4H-benzo[d][1,3]dioxin-4-ones. The process is affected by the substitution on the aryl and the allyl units.

Development of A New Delivery System Based on Drug-Loadable Electrospun Nanofibers for Psoriasis Treatment

“…Methyl salicylate was synthesized from the esterification of salicylic acid in a solution of methanol and sulfuric acid by following the method proposed by Carrillo-Arcos et al (2016) [35]. Briefly, the 2-hydroxybenzoic acid (28.96 mmol) was dissolved in 60 mL of methanol, and then sulfuric acid (98%, 2 mL) was added dropwise to the solution, and the mixture was stirred at reflux for 18 h. Next, the solvent of the reaction was removed by vacuum rotary-evaporation, and the crude product was neutralized to pH 5–6 with a solution of NaOH (1 M, 50 mL), which was extracted three times with dichloromethane (3 × 50 mL).…”

Chemo- and regioselective benzylic C(sp3)–H oxidation bridging the gap between hetero- and homogeneous copper catalysis

“…This was prepared by a modified method from literature report ( Carrillo-Arcos et al., 2016 ). To a solution of 14 (325 mg, 0.5 mmol, 1 equiv) in DMF-water (5 mL, 8:1) taking in a 25 mL round bottom flask with guard tube was added NaH (60% purity, 30 mg, 1.5 equiv) at 0°C and stirred for 10 min.…”

Recent progress in catalytic acyloxylation of C(sp3)‐H bonds

“…[ 77 ] Allylic functionalizations with retention of the heteroatom (O, N) attached allyl moiety have been extremely rare because of the undesired deallylation under palladium catalysis. [ 78 ] Therein, formation of deallylation products was suppressed via addition of bis ‐sulfoxide ligand, affording products of the type 112 and 114 with six‐ or five‐membered rings with high chemo‐, regio‐ and stereoselecitivity (Scheme 17). [ 77 ]…”

“…[77] Allylic functionalizations with retention of the heteroatom (O, N) attached allyl moiety have been extremely rare because of the undesired deallylation under palladium catalysis. [78] Therein, formation of deallylation products was suppressed via addition of bis-sulfoxide ligand, affording products of the type 112 and 114 with six-or five-membered rings with high chemo-, regio-and stereoselecitivity (Scheme 17). [77] 2.1.7 | Acyloxylation of other substrates Aromatic ketones and aldehydes have been rarely used as substrates for the C(sp 3 )-H acyloxylation reactions, because of the propensity of the CHO group to undesired oxidation, as well as competitive metal insertions into formyl C-H bonds and the weak coordination ability of carbonyl groups.…”