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An electroreductive deoxygenative carboxylation of alkyl oxalates with CO2 is demonstrated for the first time, which offers a general and scalable method for obtaining various carboxylic acids. This electrochemical method features a broad substrate scope and mild reaction conditions; various secondary benzyl alcohols and non-benzylic alcohols, primary benzyl alcohols and non-benzylic alcohols, and tertiary benzyl alcohols and non-benzylic alcohols can be converted into the corresponding carboxylic acids in good to excellent yields. Importantly, this electroreductive deoxygenative carboxylation reaction also offers a mild and straightforward route to access drug molecules, such as ibuprofen, (±) naproxen, fenoprofen, hexaprofen, and biprofen. [ABSTRACT FROM AUTHOR]

Here we report a visible-light facilitated radical addition strategy for the preparation of various natural or unnatural α-amino acids from readily available glycine derivatives and alkenes. A key aspect in achieving this side carbon chain introduction reaction, while circumventing the well-documented cyclization pathway, was the employment of a radical-polar crossover strategy under redox neutral conditions. [ABSTRACT FROM AUTHOR]

The C(sp3)−H bond decyanative arylations of diverse symmetrical and unsymmetrical BIMs have been successfully accomplished. Aromatic nitriles were utilized as components in the presence of thiobenzoic acid (TBA) under visible‐light irradiation. These redox‐neutral protocols provide a highly efficient and practical strategy for the synthesis of a broad range of bis(indolyl)‐substituted and mono(indolyl)‐substituted hetero‐triarylmethanes. Moreover, this synthetic approach has been expanded to the construction of indole‐substituted triarylmethanes bearing all‐carbon quaternary stereocenters. It is noteworthy that the preparation of the natural product Arsindolin A was effectively achieved using this methodology. [ABSTRACT FROM AUTHOR]

Abstract: A semi-synthetic route to the D-ring analogs of (-)-epigallocatechin gallate (EGCG) from the relatively abundant (-)-epigallocatechin (EGC), isolated from green tea leaves, is described. A natural product (13), found [...]

Main observation and conclusion: An oxidative tandem (4+2)‐cyclization/aromatization of N‐aryl glycine derivatives with electron‐deficient alkenes was first achieved using Ru(bpy)3Cl2 as a photocatalyst and TBHP as an oxidant in combination with visible‐light irradiation by blue LEDs. One‐electron oxidation and the following α‐deprotonation of glycine derivatives afford α‐amino alkyl radicals, which were then trapped by electrophilic maleimides. As an atom‐economic and efficient method, a variety of pyrrolo[3,4‐c]quinoline‐1,3‐diones have been obtained in good yields under mild reaction conditions. [ABSTRACT FROM AUTHOR]

An efficient and diastereoselective [2+1] annulation of arylidenepyrazolones with bromides has been developed that relies on in situ formation of sulfur ylide via a direct sulfide‐catalyzed process. A variety of spirocyclopropanyl pyrazolones were achieved in good to excellent yields (up to 93% yield) with high diastereoselectives (up to 20 : 1 dr). Meanwhile, several spirocyclopropanyl compounds were also prepared from corresponding enones. This catalytic strategy exhibits good functional group tolerance, gram‐scale capacity and broad substrate scope, and provides various spirocyclopropanyl derivatives. [ABSTRACT FROM AUTHOR]

We report a catalytic oxidative C–H cyanation of glycine derivatives using a simple copper(I) catalyst with NFSI as an oxidant via a radical process to furnish α-cyano glycine derivatives, which are useful intermediates for organic synthesis. CuCl acted as both a one-electron reductant and a transition-metal catalyst in this transformation. NFSI served as a one-electron oxidant and generated a N-centered radical as a H-abstractor. The reaction displayed broad substrate scope and mild reaction conditions. [ABSTRACT FROM AUTHOR]

A visible-light-mediated aerobic α-alkylation reaction of glycine derivatives with alkyl boronic acids has been established in the presence of a Ru/Cu catalyst system, giving the desired radical coupling products efficiently. The transformation features mild reaction conditions and broad substrate scope, delivering a wide range of complex unnatural α-amino-acid derivatives. [ABSTRACT FROM AUTHOR]

A redox-neutral decarboxylative coupling reaction of heteroaryl methylamines with NHPI esters derived from aliphatic carboxylic acids has been developed. By employing a copper complex as a photocatalyst with blue LED irradiation, NHPI esters underwent one-electron reduction and heteroaryl methenamine derivatives underwent one-electron oxidation in one photo-redox catalytic cycle to form radical intermediates, respectively, followed by the recombination of these two radicals to form new C–C bonds. The methodology is illustrated by the transformation of different kinds of heteroaromatic compounds as well as primary, secondary and tertiary alkyl carboxylic acids. The reaction can be scaled up and NHPI can be recovered. Also, the reaction can be conducted in a one-pot in situ activation manner. [ABSTRACT FROM AUTHOR]

Summary of main observation and conclusion: A Cu(OAc)2/DDQ/DTBP/Py system catalyzed oxidative dehydrogenative silylation‐alkenation tandem reaction of readily available alkyl aromatic compounds with silanes was established. A variety of functionalized alkenyl organosilicon compounds were provided in good to high yields with a total β‐(E) selectivity. The control experiments revealed that the transformation might proceed through a radical pathway. [ABSTRACT FROM AUTHOR]

The one‐electron reduction (OER) can profoundly affect the structure and reactivity of organic compounds. OER induced radical decarboxylative functionalizations of redox‐active esters have gained wide concerns in this century. In this review, we present recent advances using redox‐active esters as carbon‐centered radical precursors to form carbon–carbon and carbon–heteroatom bonds. [ABSTRACT FROM AUTHOR]

The auto‐oxidative Povarov/aromatization tandem reaction of N‐aryl glycine derivatives with enamides yields a series of complex quinoline derivatives in good yields. The reactions are performed using only catalytic amount of Brønsted acid and O2. The acylamino group is used as both activating and leaving group to improve the reaction efficiency in this transformation. [ABSTRACT FROM AUTHOR]

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＝O bonds by late-stage functional group transformations. [ABSTRACT FROM AUTHOR]

A visible-light photoinduced ring opening of N-alkyl-4-piperidinols under mild conditions has been achieved. The reaction sequence involves a visible-light-induced charge-transfer complex, which promoted the S–Cl bond cleavage of sulfonyl chlorides. The generated sulfonyl radical further reacts with N-alkyl-4-piperidinol cation radicals to achieve C–N and C–C bond cleavages to yield homoallylamine products. [ABSTRACT FROM AUTHOR]

A highly efficient, metal-free, chemical oxidation of hydrazines has been implemented using environmentally friendly TCCA as oxidant. This benign protocol provides straightforward access to a wide range of azo compounds in THF in excellent yield. Altogether, 35 azo compounds were obtained in this way and scale-up preparations were performed. Additionally, a plausible mechanism was also proposed. Step-economical process, mild reaction conditions, operational simplicity, high reaction efficiency, and easy scale-up highlight the practicality of this methodology. [ABSTRACT FROM AUTHOR]

An iodine promoted cascade cycloisomerization of 1-en-6,11-diynes is presented for the easy preparation of tetrahydrobenzo[f]isoquinolines. This developed reaction system is identified as having good functional-group applicability and can be scaled up to gram quantities. In this transformation, two new cyclic frameworks and one carbonyl group are formed with four new bonds constructed. Additionally, the resulting iodo-substituted compounds could be further derived through simple elimination reactions. [ABSTRACT FROM AUTHOR]

Styrene, an extremely important compound in the chemical industry, is mainly produced by the dehydrogenation or oxidative dehydrogenation of ethylbenzene. Transformation of this raw organic material to more useful fine organic chemicals is a very significant topic. Recently, the radical difunctionalization of styrene has become a powerful and efficient tool for organic synthesis. This strategy can introduce two substituents into a styrene molecule in one step via addition to the C=C bond, enhancing the molecular complexity in a single operation with good selectivity and wide functional group compatibility. 1 Introduction 2 C-Centered Radicals 3 CF3 and Other Polyfluoroalkyl Radicals 4 N-Centered Radicals 5 P-Centered Radicals 6 O-Centered Radicals 7 S-Centered Radicals 8 Other-Atom-Centered Radicals 9 Conclusion and Perspective [ABSTRACT FROM AUTHOR]

Summary of main observation and conclusion: Oxidative dehydrogenative [3+3] annulation of benzylhydrazines with N‐sulfonylaziridines is described. A series of complex tetrahydro‐1,2,4‐triazines were produced under mild reaction conditions. [ABSTRACT FROM AUTHOR]

A copper‐catalyzed aerobic oxidative dehydrogenative reaction of glycine derivatives with α′‐angelicalactone is achieved under mild and simple reaction conditions. This strategy can be applicable to a wide range of gylcine esters, including complex substrates derived from (+)‐dehydroisoandrosterone or menthol, thus enabling the oxidative dehydrogenative ring‐opening reaction for producing diverse functionalized α‐amino‐γ‐ketopimelate derivatives in an atom‐economic manner. [ABSTRACT FROM AUTHOR]

A metal- and additive-free strategy for the synthesis of oxindoles has been achieved through a chlorine radical-induced cascade chlorination/carbocyclization of N -aryl acrylamides. Trichloroiso-cyanuric acid (TCCA) is used as both radical initiator and chlorine source. A wide range of substrates can be applied in this process to directly afford chlorinated oxindoles via C–Cl and C–C bond formation. [ABSTRACT FROM AUTHOR]

An oxygenation approach to isatins via an auto‐oxidation/intramolecular annulation tandem reaction of glycine derivatives is described. This transformation provides a metal‐free protocol for the preparation of isatin derivatives, which are important structural motifs widely found in organic molecules with various functions and privileged units for the synthesis of complex heterocycles. The reaction proceeds smoothly under mild reaction conditions and requires only Brønsted acid and oxygen. Oxygen mask: An oxygenation approach to isatins via an auto‐oxidation/intramolecular annulation tandem reaction of glycine derivatives is described. This transformation provides a metal‐free protocol for the preparation of isatin derivatives, which are important structural motifs widely found in organic molecules with various functions and privileged units for the synthesis of complex heterocycles. The reaction proceeds smoothly under mild reaction conditions and requires only a Brønsted acid and oxygen. [ABSTRACT FROM AUTHOR]

Abstract: A visible‐light‐mediated α‐hydroxymethylation of ketones using methanol as the hydroxymethylating reagent has been developed. Using 1 mol% rose bengal as the photosensitizer and air as the green oxidant, the reactions proceeded smoothly at room temperature. Experimental studies indicate the reaction proceeded via a radical pathway. [ABSTRACT FROM AUTHOR]