A New Synthesis of 2-Aroylcoumaran-3-ones by Hypervalent Iodine Oxidation of 2-Acetyl-phenyl Benzoates Using [Hydroxy(tosyloxy)iodo]benzene

meta-Chloroperbenzoic acid (mCPBA): a versatile reagent in organic synthesis

“…a-Tosyloxy ketones are very important strategic precursors for the construction of various heteroaromatics, such as thiazoles, imidazoles, imidazo[1,2-a]pyridines, oxazoles, selenazoles, pyrazoles, and benzofurans. [436][437][438][439][440][441][442][443][444][445][446][447][448][449][450][451][452][453] Interestingly, method A [PhI (0.1 eq. ), mCPBA (1.1 eq.…”

Catalytic Enantioselective α-Tosyloxylation of Ketones Using Iodoaryloxazoline Catalysts: Insights on the Stereoinduction Process

“…The solvent was removed under reduced pressure, and the crude mixture was purified by column chromatography on silica gel with EtOAc/hexanes (20:80) to provide 350 mg (66%) of 5 as a yellow oil; R f 0.25 (EtOAc/ hexanes, 20:80); 1 25 D +3.72 (c 0.43, CHCl 3 ). (S)-4-tert-Butyl-2-(8-iodonaphthalen-1-yl)-4,5-dihydrooxazole (6). To a solution of 8-iodo-1-naphthoic acid 26 (1.00 g, 3.36 mmol) in 25.0 mL of SOCl 2 was added 5 drops of DMF.…”

“…In particular, the α-tosyloxylation of ketones enables the introduction of a potent leaving group alpha to a carbonyl. Additionally, and in contrast to α-halo ketones, these electrophiles are not lacrymators . A method to access such compounds relies on the use of toxic thallium­(III) reagents .…”

“…Additionally, and in contrast to αhalo ketones, these electrophiles are not lacrymators. 6 A method to access such compounds relies on the use of toxic thallium(III) reagents. 7 An iodine(III)-mediated variant has been popularized by Koser et al 8 and uses hydroxy(tosyloxy)iodobenzene 9 (Scheme 1a, HTIB).…”

7.07 α-Oxygenation of Carbonyl Compounds

“…152 Moriarty reported the synthesis of keto-g-lactones from 5-ketoacids in 1990, 153 and the reaction sequence is often utilized in the synthesis of oxygen-containing heterocycles. 154 A catalytic version of this reaction was recently achieved with Ochiai's established mCPBA protocol (Scheme 55). 155 Moderate yields were obtained due to byproducts from Baeyer-Villiger oxidation.…”