1c:I[419806,["/_next/static/chunks/bb923814e1f4d2e9.js","/_next/static/chunks/dd3ee9f5b7716ca6.js","/_next/static/chunks/4204a0ae82542ca8.js","/_next/static/chunks/1270dead247da766.js","/_next/static/chunks/6e1aa89a642f40be.js","/_next/static/chunks/2d7aa753e81324a8.js","/_next/static/chunks/8ffd0b71567920d8.js","/_next/static/chunks/67ea6dfd21f16c5f.js","/_next/static/chunks/24eb4379f68013fd.js","/_next/static/chunks/b8cd775ffdf935bd.js","/_next/static/chunks/983103cd9eb7b428.js","/_next/static/chunks/263f2cdcb9aa2341.js","/_next/static/chunks/294b9525248c8e5f.js"],"default"] 1d:T411,The selective introduction of fluorine atom(s) and fluorinated moieties into organic molecules has become an important and fast-growing research field, since fluorine atoms play crucial roles in life science and materials science-related applications. Similar to the trifluoromethyl group, both difluoromethyl and monofluoromethyl groups can often bring about many beneficial effects to the target molecules, and a variety of CF(2)H- and CH(2)F-containing pharmaceuticals and agrochemicals have been developed. Among the synthetic methods for CF(2)H- and CH(2)F-containing compounds, selective di- and monofluoromethylation (i.e., introduction of CF(2)H and CH(2)F groups into organic molecules) represent one of the most straightforward synthetic methods and thus can be conveniently used in the synthetic design. This feature article summarizes the presently known selective difluoromethylation and monofluoromethylation methods, including nucleophilic, electrophilic, and free radical di- and monofluoromethylation reagents and reactions.1e:T4ee,Difluorocarbene is a versatile, reactive intermediate for use in organic synthesis. Over the past decade, significant progress has been made in difluorocarbene chemistry owing to the increasing demand for various fluorinated molecules. Not only the substrate scope for some classical difluorocarbene reagents has been largely expanded, but also new and environmentally friendly difluorocarbene reagents for difluoromethylation and gem-difluorocyclization have been developed. This review summarizes the difluoromethylation, gem-difluorocyclopropanation, gem-difluorocyclopropenation, gem-difluoroolefination, and trifluoromethylation achieved in the last decade using both the classical and the new difluorocarbene sources. 1 Introduction 2 Difluorocarbene Sources 3 Difluoromethylation 3.1 O-Difluoromethylation 3.2 S-Difluoromethylation 3.3 N-Difluoromethylation 3.4 Difluoromethylation of Ambident N,O- and N,S-Nucleophiles 3.5 Se- and P-Difluoromethylation 3.6 C-Difluoromethylation 3.7 Sn-Difluoromethylation 4 gem-Difluorocyclization 4.1 gem-Difluorocyclopropanation 4.2 gem-Difluorocyclopropenation 5 gem-Difluoroolefination and Related Reactions 6 Trifluoromethylation 7 Miscellaneous 8 Conclusions1f:T47b,A new olefination protocol for transition-metal-free cross-coupling of two carbene fragments arising from two different sources, namely, a nonfluorinated carbene fragment resulting from a diazo compound and a difluorocarbene fragment derived from Ruppert-Prakash reagent (TMSCF3) or TMSCF2Br, has been developed. This gem-difluoroolefination proceeds through the direct nucleophilic addition of diazo compounds to difluorocarbene followed by elimination of N2. Compared to previously reported Cu-catalyzed gem-difluoroolefination of diazo compounds with TMSCF3, which possesses a narrow substrate scope due to a demanding requirement on the reactivity of diazo compounds and in-situ-generated CuCF3, this transition-metal-free protocol affords a general and efficient approach to various disubstituted 1,1-difluoroalkenes, including difluoroacrylates, diaryldifluoroolefins, as well as arylalkyldifluoroolefins. In view of the ready availability of diazo compounds and difluorocarbene reagents and versatile transformations of 1,1-difluoroalkenes, this new gem-difluoroolefination method is expected to find wide applications in organic synthesis.

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