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The rapid assembly of valuable cyclic amine architectures in a single step from simple precursors has been recognized as an ideal platform in term of efficiency and sustainability. Although a vast number of studies regarding cyclic amine synthesis has been reported, new synthetic disconnection approaches are still high in demand. Herein, we report a catalytic radical‐polar crossover cycloaddition to cyclic amine synthesis triggered from primary sulfonamide under photoredox condition. This newly developed disconnection, comparable to established synthetic approaches, will allow to construct β, β‐disubstituted cyclic amine and β‐monosubstituted cyclic amine derivatives efficiently. This study highlights the unique utility of primary sulfonamide as a bifunctional reagent, which acts as a radical precursor and a nucleophile. The open‐shell methodology demonstrates broad tolerance to various functional groups, drug derivatives and natural products in an economically and sustainable fashion. [ABSTRACT FROM AUTHOR]

Despite the importance of heteroatom‐substituted cyclopropane derivatives in drug design and organic synthesis, cyclopropanethiols remain critically underexplored. Inspired by the wide use of the Newman‐Kwart rearrangement to access valuable thiophenols from phenol feedstocks, we report the development of a photocatalytic approach for efficient ambient temperature aliphatic O‐ to S‐rearrangement on tertiary cyclopropanol derivatives. After demonstrating that a range of cyclopropanethiols—that are difficult to access by other methods—can be obtained with this strategy, we show that these rearranged products can be easily hydrolyzed and further derivatized. We conclude this study with mechanistic findings that enabled an initial extension of this approach toward other classes of aliphatic alcohols. [ABSTRACT FROM AUTHOR]

We report a highly enantioselective intermolecular C−H bond silylation catalyzed by a phosphoramidite‐ligated iridium catalyst. Under reagent‐controlled protocols, propargylsilanes resulting from C(sp3)−H functionalization, as well the regioisomeric and synthetically versatile allenylsilanes, could be obtained with excellent levels of enantioselectivity and good to excellent control of propargyl/allenyl selectivity. In the case of unsymmetrical dialkyl acetylenes, good to excellent selectivity for functionalization at the less‐hindered site was also observed. A variety of electrophilic silyl sources (R3SiOTf and R3SiNTf2), either commercial or in situ‐generated, were used as the silylation reagents, and a broad range of simple and functionalized alkynes, including aryl alkyl acetylenes, dialkyl acetylenes, 1,3‐enynes, and drug derivatives were successfully employed as substrates. Detailed mechanistic experiments and DFT calculations suggest that an η3‐propargyl/allenyl Ir intermediate is generated upon π‐complexation‐assisted deprotonation and undergoes outer‐sphere attack by the electrophilic silylating reagent to give propargylic silanes, with the latter step identified as the enantiodetermining step. [ABSTRACT FROM AUTHOR]

Herein, an electrochemically driven NiH‐catalyzed reductive coupling of alkyl halides and alkyl alkenes for the construction of Csp3−Csp3 bonds is firstly reported. Notably, alkyl halides serve dual function as coupling substrates and as hydrogen sources to generate NiH species under electrochemical conditions. The tunable nature of this reaction is realized by introducing an intramolecular coordinating group to the substrate, where the product can be easily adjusted to give the desired branched products. The method proceeds under mild conditions, exhibits a broad substrate scope, and affords moderate to excellent yields with over 70 examples, including late‐stage modification of natural products and drug derivatives. Mechanistic insights offer evidence for an electrochemically driven coupling process. The sp3‐carbon‐halogen bonds can be activated through single electron transfer (SET) by the nickel catalyst in its low valence state, generated by cathodic reduction, and the generation of NiH species from alkyl halides is pivotal to this transformation. [ABSTRACT FROM AUTHOR]

1‐Aryl‐substituted bicyclo[1.1.1]pentanes (BCPs) are an important class of BCP derivatives with widespread application in drug development. Most syntheses of these materials require multiple chemical steps via BCP electrophiles or nucleophiles derived from [1.1.1]propellane. Although one‐step, multicomponent radical cross‐coupling reactions could provide a more sustainable and rapid route to access diverse heteroarylated BCPs, current approaches are limited to tertiary alkyl radicals, leading to a decrease in their practical value. In this study, a conceptually different approach enabled by a radical multicomponent heteroarylation of [1.1.1]propellane to access functionalized heteroarylated BCPs is described. Importantly, this protocol is compatible with primary‐, secondary‐, and tertiary aliphatic radicals, as well as various fluoroalkyl radical sources, thus enabling rapid library generation of sought‐after BCP derivatives for drug development. [ABSTRACT FROM AUTHOR]

Efficient protocols for accessing iodo‐substituted diaryl and aryl(vinyl) sulfides have been developed using iodonium salts as reactive electrophilic arylation and vinylation reagents. The reactions take place under transition‐metal‐free conditions, employing odorless and convenient sulfur reagents. A wide variety of functional groups are tolerated in the S‐diarylation, enabling the regioselective late‐stage application of several heterocycles and drug molecules under mild reaction conditions. A novel S‐difunctionalization pathway was discovered using vinyliodonium salts, which proceeds under additive‐free reaction conditions and grants excellent stereoselectivity in the synthesis of aryl(vinyl) sulfides. A one‐pot strategy combining transition‐metal‐free diarylation and subsequent reduction provided facile access to electron‐rich thioanilines and a direct synthesis of a potential drug candidate derivative. The retained iodo group allows a wide array of further synthetic transformations. Mechanistic insights were elucidated by isolating the key intermediate, and the relevant energy profile was substantiated by DFT calculations. [ABSTRACT FROM AUTHOR]

Herein, an electroreductive carboxylation of organic carbon‐halogen bonds (X=Br and Cl) promoted by catalytic amounts of naphthalene as an organic mediator is reported. This transformation proceeds smoothly under mild conditions with a broad substrate scope of 59 examples, affording the valuable and versatile carboxylic acids in moderate to excellent yields without the need of costly transition metal, wasted stoichiometric metal reductants, or sacrificial anodes. Further late‐stage carboxylations of natural product and drug derivatives demonstrate its synthetic utility. Mechanistic studies confirmed the activation of carbon‐halogen bonds via single‐electron transfer and the key role of naphthalene in this reaction. [ABSTRACT FROM AUTHOR]

Herein, an efficient and facile approach to valuable β‐hydroxy acid derivatives from readily available aryl epoxides and CO2 with high chemo‐ and regioselectivity under mild and sustainable electrochemical conditions is described. This approach showed broad substrate scope and good functional‐group compatibility. In addition to aryl epoxides, four‐ to six‐membered aryl cyclic ethers could all be tolerated in the reaction to provide synthetically useful hydroxy acids with high efficiency. Further late‐stage carboxylation of complex molecules and drug derivatives demonstrated its potential application in the pharmaceutical industry. Mechanistic studies disclosed possible reaction pathways. [ABSTRACT FROM AUTHOR]

C(sp3)−H bond coupling with carbon electrophiles remains rarely explored under thermo‐driven hydrogen atom transfer (HAT) conditions due to the challenge of integrating oxidation and reduction in a single operation. We report here a Ni‐catalyzed arylation and alkylation of C(sp3)−H bonds with organohalides to forge C(sp3)−C bonds by merging economical Zn and tBuOOtBu (DTBP) as the external reductant and oxidant. The mild and easy‐to‐operate protocol enables facile carbofunctionalization of N‐/O‐α‐ and cyclohexane C−H bonds, and preparation of a few intermediates of bioactive compounds and drug derivatives. Preliminary mechanistic studies implied addition of an alkyl radical to a NiII salt. [ABSTRACT FROM AUTHOR]

Site‐selective incorporation of deuterium into biologically active compounds is of high interest in pharmaceutical industry. We present a mild and environmentally benign metal‐free method for the remote selective radical C−H monodeuteration of aliphatic C−H bonds in various amides with inexpensive heavy water (D2O) as the deuterium source. The method uses the easily installed N‐allylsulfonyl moiety as an N‐radical precursor that generates the remote C‐radical via site‐selective 1,5‐ or 1,6‐hydrogen atom transfer (HAT). Methyl thioglycolate, that readily exchanges its proton with D2O, serves as the radical deuteration reagent and as a chain‐carrier. The highly site‐selective monodeuteration has been applied to different types of unactivated sp3‐C−H bonds and also to the deuteration of C−H bonds next to heteroatoms. The potential utility of this method is further demonstrated by the site‐selective incorporation of deuterium into natural product derivatives and drugs. [ABSTRACT FROM AUTHOR]

A simple and efficient protocol to generate amidyl radicals from amine functionalities through a manganese‐mediated atom‐transfer reaction has been developed. This approach employs an earth‐abundant and inexpensive manganese complex, Mn2(CO)10, as the catalyst and visible light as the energy input. Using this strategy, site‐selective chlorination of unactivated C(sp3)−H bonds of aliphatic amines and intramolecular/intermolecular chloroaminations of unactivated alkenes were readily realized under mild reaction conditions, thus providing efficient access to a range of synthetically valuable alkyl chlorides, chlorinated pyrrolidines, and vicinal chloroamine derivatives. These practical reactions exhibit a broad substrate scope and tolerate a wide array of functional groups, and complex molecules including various marketed drug derivatives. [ABSTRACT FROM AUTHOR]

A radical‐mediated monofluoroalkylative alkynylation of alkenes is disclosed for the first time. The reaction demonstrates a remarkably broad substrate scope in which both activated and unactivated alkenes are suitable starting materials. The concurrent addition of an alkynyl and a monofluoroalkyl group onto an alkene proceeds through a docking–migration sequence, affording a vast array of valuable fluoroalkyl‐substituted alkynes. Many complex natural products and drug derivatives are readily functionalized, demonstrating that this method can be used for late‐stage alkynylation. [ABSTRACT FROM AUTHOR]