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Herein, the use of economically and environmentally friendly bis(pinacolato)diboron (B2Pin2) is described as a non‐metallic reductant in mediating Ni‐catalyzed C(sp3)–C(sp2) reductive cross‐coupling of alkyl electrophiles with aryl/vinyl halides. This method exhibits excellent suitability for heteroaryl halides and alkyl halides/Katritzky salts. The present study is compatible with an in situ halogenation of alcohol method, allowing for selective mono‐functionalization of diols and bio‐relevant alcohols (e.g., carbohydrates). The use of B2Pin2 shows potential for easy scalability without introducing additional metal impurities into the products. It is observed for the first time in the realm of cross‐electrophile coupling chemistry that B2Pin2 can sever as a reductant to reduce NiII to Ni0. This mechanistic insight may inspire the development of new reductive bond‐forming methodologies that can otherwise be difficult to achieve with a metal reductant. [ABSTRACT FROM AUTHOR]

In this short review, we summarize the recent developments on thermo-driven C(sp3)–O bond radical scission methods and their applications in the construction of C(sp3)–C bonds via conjugate addition with activated double bonds and reductive coupling mediated by economic 3d metals, in particular nickel. We have arranged the review based on three approaches for C(sp3)–O bond radical scission (vide infra). After generating the radical intermediates, their subsequent transformation into C(sp3)–C bonds enabled by C(sp3)–O cross-electrophile coupling with carbon electrophiles is discussed in detail. 1 Introduction 2 Direct Single-Electron Transfer to a C(sp3)–O Bond 3 Radical Scission of Activated C(sp3)–O Bonds via Single-Electron Transfer to Protecting Groups 4 In Situ Activation of Alcohols 5 Summary and Outlook [ABSTRACT FROM AUTHOR]

An efficient silver‐promoted decarboxylative gem‐difluoromethylenation of aryl‐ or alkyl‐substituted α,β‐unsaturated carboxylic acids with readily available benzo‐1,3‐diazolic difluoromethyl bromides has been developed. This convenient transformation demonstrated good functional‐group tolerability and broad substrate scope, and afforded the allylic difluorides in good to excellent yields with exclusive E‐stereoselectivity under mild reaction conditions. [ABSTRACT FROM AUTHOR]

An efficient kinetic resolution of N-aryl β-amino alcohols has been developed via asymmetric para-aminations of anilines with azodicarboxylates enabled by chiral phosphoric acid catalysis. Broad substrate scope and high kinetic resolution performances were afforded with this method. Control experiments supported the critical roles of the NH and OH group in these reactions. [ABSTRACT FROM AUTHOR]

Axially chiral diaryl ethers are a type of unique atropisomers bearing two potential axes, which have potential applications in a variety of research fields. However, the catalytic enantioselective synthesis of these diaryl ether atropisomers is largely underexplored when compared to the catalytic asymmetric synthesis of biaryl or other types of atropisomers. Herein, we report a highly efficient catalytic asymmetric synthesis of diaryl ether atropisomers through an organocatalyzed enantioselective desymmetrization protocol. The chiral phosphoric acid-catalyzed asymmetric electrophilic aromatic aminations of the symmetrical 1,3-benzenediamine type substrates afforded a series of diaryl ether atropisomers in excellent yields and enantioselectivities. The facile construction of heterocycles by the utilizations of the 1,2-benzenediamine moiety in the products provided access to a variety of structurally diverse and novel azaarene-containing diaryl ether atropisomers., (© 2023 Wiley-VCH GmbH.)

An efficient approach for asymmetric synthesis of planar-chiral macrocycles (paracyclophanes) has been disclosed through enantioselective electrophilic aromatic aminations with azodicarboxylates enabled by chiral phosphoric acid catalysis. A wide range of chiral macrocycles bearing varied ring sizes (16 to 23-membered) and functional group-containing ansa chains were readily afforded using this method, with excellent yields and high enantioselectivities (23 examples, up to 99.5 : 0.5 er). Experimental studies and DFT calculations were performed to elucidate the mechanism and origin of stereoselectivities of these reactions. Preliminary utilization of the planar-chiral macrocycle as chiral organocatalyst showcased the potential applications of these novel chiral skeletons., (© 2022 Wiley-VCH GmbH.)

A Ni-catalyzed reductive cross-coupling between α-C-tosyl peptides and Csp 2 triflates/halides has been developed. This protocol enables the formation of various unnatural di- and tripeptides containing vinyl and aryl side chains, and it expands the applications of Ni-catalyzed reductive cross-coupling in late-stage diversification of peptides.