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Aryl radicals were generated for the first time from cheap and easily available aryl acyl peroxides in eco-friendly ethyl acetate under ambient conditions and visible-light illumination in the absence of any additive, metal catalyst, or external photosensitizer. The present arylation of quinoxalin-2(1H)-ones was chemo- and regioselective, and provided good access to various 3-arylquinoxalin-2(1H)-ones. This journal is

A new copper-catalyzed two-component amino-benzoyloxylation of unactivated alkenes of unsaturated ketoximes with O-benzoylhydroxylamines as the benzoyloxy sources is developed. Chemoselectivity of this method toward amino-benzoyloxylation or oxy-benzoyloxylation of alkenyl ketoximes relies on the position of the tethered olefins, and provides an external-oxidant-free alkene difunctionalization route that directly utilizes O-benzoylhydroxylamines as the benzoyloxy radical precursors and internal oxidants for the divergent synthesis of cyclic nitrones and isoxazolines.

The Ni-catalyzed oxidation of unactivated alkanes, including the oxidation of polyethylenes, by meta-chloroperbenzoic acid (mCPBA) occur with high turnover numbers under mild conditions, but the mechanism of such transformations has been a subject of debate. Putative, high-valent nickel-oxo or nickel-oxyl intermediates have been proposed to cleave the C-H bond, but several studies on such complexes have not provided strong evidence to support such reactivity toward unactivated C(sp3)-H bonds. We report mechanistic investigations of Ni-catalyzed oxidations of unactivated C-H bonds by mCPBA. The lack of an effect of ligands, the formation of carbon-centered radicals with long lifetimes, and the decomposition of mCPBA in the presence of Ni complexes suggest that the reaction occurs through free alkyl radicals. Selectivity on model substrates and deuterium-labeling experiments imply that the m-chlorobenzoyloxy radical derived from mCPBA cleaves C-H bonds in the alkane to form an alkyl radical, which subsequently reacts with mCPBA to afford the alcohol product and regenerate the aroyloxy radical. This free-radical chain mechanism shows that Ni does not cleave the C(sp3)-H bonds as previously proposed; rather, it catalyzes the decomposition of mCPBA to form the aroyloxy radical.

A novel and facile cobalt-catalyzed selective aroylation of primary amines with aroyl peroxides was developed for the synthesis of aryl amides. It was unprecedented that C[sbnd]N bond formation product was selectively generated without the common N[sbnd]O bond formation product. Aroyl peroxides act as the sole aroylation reagent without additional base or oxidant. The reactions proceeded under mild conditions and showed broad substrates scope with a series of primary amines and aroyl peroxides.

The oxygenation of 8-aminoquinoline amides by benzoyl peroxide at the C5 position in water is developed in the absence of a transition metal catalyst, affording the desired products in moderate to good yields of up to 88%. Mechanism studies reveal that the reaction would involve a radical process.

In this paper, the direct acyloxylation of the α-C(sp2)-H bond in tertiary β-enaminones is accomplished under catalyst-free conditions and ambient temperature by using aroyl peroxides as coupling partners. By means of a thermoinduced free-radical pathway, the present method enables facile and efficient synthesis of both acyloxylated chromones and enaminones.

An efficient Cu-catalyzed Csp3-O coupling of peroxides with haloalkanes is described. High yields of products were achieved under mild conditions. Significantly, in addition to primary alkyl halides, secondary alkyl halogenated hydrocarbons could also be applied to this system. The new reaction system could tolerate a wide range of organic peroxides.

An efficient Pd-catalyzed decarboxylative ortho-arylation of amides with aryl acylperoxides was developed. A variety of anilides reacted with aryl acylperoxides to afford the corresponding ortho-arylation products, and N-methoxyarylamides generated phenanthridinones. This journal is

A palladium(II)-catalyzed ortho-benzoxylation of 2-arylpyridines with aryl acylperoxides was developed. With pyridyl as directing group, the benzoxylation reaction exhibits remarkable regioselectivity and excellent functional group tolerance, providing the products in up to 87% yield.

A Pd(OAc)2-catalyzed protocol for decarboxylative arylation of aromatic C-H bond was developed using aryl acylperoxides as inexpensive aryl sources. Substrates containing pyridyl, oxime, and oxazoline groups undergo effectively ortho-selective C-H arylation with excellent functional group tolerance. This arylation should begin by directing-group-assisted cyclopalladation, followed by the reaction of the palladacycle with aryl radicals generated in situ by thermal decomposition of the peroxides.

A quinone methide diterpene: abietaquinone methide, which possesses potent anti-methicillin-resistant Staphylococcus aureus (MRSA) and anti-vancomycin- resistant Enterococcus (VRE) activities, was synthesized via efficiently ortho-oxidation of ferruginol derived from industrially available dehydroabietic acid. ortho-Oxidation of phenols was developed to give mono esters of catechols using a stable diacyl peroxide, bis(4-chlorobenzoyl) peroxide (m-chlorobenzoyl peroxide: mCBPO) which was synthesized from meta-chlorobenzoic acid. Efficient one pot ortho-oxidation reaction of phenol with an adduct of meta-chloroperbenzoic acid (mCPBA) with dicyclohexylcarbodiimide (DCC) was also reported.

This contribution describes an unexpected incident that occurred during oxidation of sulfide to sulfoxide using m-CPBA (m-chloroperoxybenzoic acid) as oxidant in DMF as a solvent on a pilot-plant scale. Investigation in the incident indicated that initial

2-Substituted and 1,2-disubstituted indoles react with m-chloroperbenzoic acid and hydrogen peroxide in the presence of acid or calcium chloride affording 2- and 3-(3-oxoindol-2-yl)indoles; whereas 2,3-disubstituted indoles, reacting with the same oxidant

m-Chloroperbenzoic acid (MCPBA) oxidatively assisted reactions at 25 deg C between straight chain primary alkyl iodides and sodium nitrocyanamide to give corresponding alkyl nitrocyanamides (N-alkylation) and N-alkoxy-N'-cyanodiazene N-oxides (O-alkylation).Each alkyl nitrocyanamide thermolysed to an alkyl isocyanate.In the absence of oxidative assistance sodium nitrocyanamide suspended in an inert solvent (25 deg C to 110 deg C) did not convert straight chain primary alkyl halides.Simple secondary and tertiary alkyl iodides and isobutyl iodide in the presence of MCPBA and sodium nitrocyanamide were converted to intractable mixtures that did not contain detectable amounts of alkyl nitrocyanamides, isocyanates, or N-alkoxy-N'-cyanodiazene N-oxides.This differential reactivity between the various types of alkyl iodides was supported by a similar conversion of straight chain primary alkyl iodides to corresponding azides and other alkyl iodides to intractable mixtures on treatment with sodium azide under conditions that brought about no reaction in the absence of oxidative assistance of MCPBA.Alkyl iodides were unreactive (25 deg C to 110 deg C) to sodium cyanate in the presence or absence of peroxides.

N-Benzoylperoxycarbamic acid (BPC) was found to react generally with imines and azines to form oxaziridines rather than N-oxides.The imine products were stable, but those found from azines apparently were unstable and converted to ketones or aldehydes plus diazo compounds.