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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]

A series of cyclohexyl‐fused SPINOL‐derived phosphoric acids (Cy‐SPA) have been developed to catalyze the kinetic resolution of 2‐N‐acylamido tertiary allylic alcohols, providing access to chiral oxazolines bearing C‐2 alkyl substituents with high enantioselectivities (with s‐factors up to 153). Gram‐scale reaction with 1 mol% catalyst loading and transformations of the chiral products demonstrates the value of these methods. [ABSTRACT FROM AUTHOR]

An AgI-mediated ethoxycarbonyldifluoromethylation of isocyanides has been developed. This radical cascade reaction involves the addition of difluoromethylene radical to the isocyanide functionality, and subsequent homolytic aromatic substitution to give difluoromethylated phenanthridines with a good functional-group tolerance. [ABSTRACT FROM AUTHOR]

A simple AgI-mediated direct difluoromethylation reaction of activated alkenes by using TMSCF2COOEt (TMS = trimethylsilyl) under mild reaction conditions has been described. This reaction tolerates a variety of functional groups and allows for a highly efficient synthesis of various difluoro-containing oxindoles. Mechanistic investigations indicate that a difluoromethyl radical initiated the cascade sequence by undergoing an addition reaction to the alkene. [ABSTRACT FROM AUTHOR]

A mild, versatile and efficient method for the silver(i)-catalyzed oxidative decarboxylative gem-difluoromethylenation has been developed. The radical cascade reaction comprises the addition of an oxidatively generated difluoromethylene radical to the isonitrile functionality and subsequent homolytic aromatic substitution. It provides a novel and efficient access to the C–CF2 bond formation. [ABSTRACT FROM AUTHOR]

Efficient direct gem-difluoromethylenation of an sp3-hybridized carbon center in benzyl bromides using benzo-1,3-azolic (oxa-, thia- or aza-) difluoromethyl bromides for construction of a CH2–CF2 linkage has been developed through radical/radical C–C cross-coupling via two separate single electron transfer processes (SET) under the promotion of different copper sources. [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.)