A Mn-catalyzed remote C(sp3)-H bond peroxidation triggered by radical trifluoromethylation of unactivated alkenes

A manganese-catalyzed radical relay strategy for the remote trifluoromethylation-peroxidation of unactivated alkenes is disclosed. The electrophilic CF3 group was added to the C[double bond, length as m-dash]C double bonds to afford remote C-centered radicals upon 1,5-HAT, which could be efficiently trapped by Mnn+1OOBu-t species to deliver 1,6-difunctionalized products selectively under mild conditions. t-BuOOH serves as both the oxidant and the peroxy precursor in this transformation.

Organic synthesis with the most abundant transition metal–iron: from rust to multitasking catalysts

The promising aspects of iron in synthetic chemistry are being explored for three-four decades as a green and eco-friendly alternative to late transition metals. This present review unveils these rich iron-chemistry towards different transformations.

Peroxidation of 3,4-dihydro-1,4-benzoxazin-2-ones

The sp³-C-H peroxidation of 3,4-dihydro-1,4-benzoxazin-2-ones was achieved under mild and simple catalyst-free reaction conditions. A range of biologically important alkylated benzoxazinone peroxides are synthesized in high yield with a good functional group tolerance. The C(sp³)-OO bond was constructed efficiently and could be further converted into C(sp³)-C(sp³), C(sp³)-C(sp²), C(sp³)-C(sp), C-P and C[double bond, length as m-dash]O bonds by late-stage functional group transformations.

Highly Selective Synthesis of 2-tert-Butoxy-1-Arylethanones via Copper(I)-Catalyzed Oxidation/tert-Butoxylation of Aryl Olefins with TBHP

A practical and environmentally friendly protocol for the selective oxidation of aryl olefins to arylethanone derivatives by using a Cu(I) catalyst and tert-butyl hydroperoxide (TBHP) has been developed. A series of 2-tert-butoxy-1-arylethanones were obtained in moderate to good yields under mild conditions with high selectivity. In this method, TBHP acts not only as an oxidant but also as the tert-butoxy and carbonyl oxygen sources. This enables one-step oxidation/tert-butoxylation. Various allyl peroxides were also synthesized from allyl substrates.

Thiyl radical promoted iron-catalyzed-selective oxidation of benzylic sp3 C–H bonds with molecular oxygen

A ligand-free iron-catalyzed method for the oxygenation of benzylic sp³ C–H bonds by molecular oxygen (1 atm) using a thiyl radical as a cocatalyst has been developed.

An efficient method for the preparation of tert-butyl esters from benzyl cyanide and tert-butyl hydroperoxide under the metal free condition

A novel protocol to synthesize tert-butyl esters from benzyl cyanides and tert-butyl hydroperoxide has been successfully achieved. Csp³–H bond oxidation, C–CN bond cleavage and C–O bond formation proceeded smoothly in one pot under the metal-free condition.

Cs2CO3-promoted polycondensation of CO2 with diols and dihalides for the synthesis of miscellaneous polycarbonates

A one-pot protocol for the direct synthesis of polycarbonates through polycondensation of diols, dihalides and CO₂ in the presence of Cs₂CO₃ is described.

Cross-dehydrogenative coupling for the intermolecular C-O bond formation

The present review summarizes primary publications on the cross-dehydrogenative C-O coupling, with special emphasis on the studies published after 2000. The starting compound, which donates a carbon atom for the formation of a new C-O bond, is called the CH-reagent or the C-reagent, and the compound, an oxygen atom of which is involved in the new bond, is called the OH-reagent or the O-reagent. Alcohols and carboxylic acids are most commonly used as O-reagents; hydroxylamine derivatives, hydroperoxides, and sulfonic acids are employed less often. The cross-dehydrogenative C-O coupling reactions are carried out using different C-reagents, such as compounds containing directing functional groups (amide, heteroaromatic, oxime, and so on) and compounds with activated C-H bonds (aldehydes, alcohols, ketones, ethers, amines, amides, compounds containing the benzyl, allyl, or propargyl moiety). An analysis of the published data showed that the principles at the basis of a particular cross-dehydrogenative C-O coupling reaction are dictated mainly by the nature of the C-reagent. Hence, in the present review the data are classified according to the structures of C-reagents, and, in the second place, according to the type of oxidative systems. Besides the typical cross-dehydrogenative coupling reactions of CH- and OH-reagents, closely related C-H activation processes involving intermolecular C-O bond formation are discussed: acyloxylation reactions with ArI(O2CR)2 reagents and generation of O-reagents in situ from C-reagents (methylarenes, aldehydes, etc.).

Iron-catalyzed aerobic oxidative functionalization of sp3 C–H bonds: a versatile strategy for the construction of N-heterocycles

Iron-catalyzed aerobic oxidative functionalization of sp³ C–H bonds using a biofriendly iron catalyst in combination with O₂ or air as the sole oxidant has been developed for the construction of N-heterocycles from easily available carboxylic acid derivatives and o-substituted anilines.

Iron-catalyzed/mediated oxidative transformation of C–H bonds

Iron-catalyzed/mediated C–H bond oxidation has been demonstrated as one of practical and straightforward tools in synthetic chemistry.