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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 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]

The first AgI-mediated C-H ethoxycarbonyl difluoromethylation with TMSCF2COOEt (TMS = trimethylsilyl) has been developed. The radical difluoromethylation proceeds smoothly to give the difluoromethylated arenes in moderate to high yields with Friedel-Crafts-type regioselectivity. Mechanistic studies indicate that the innate C-H difluoromethylation proceeds through an electrophilic radical-type pathway. [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]