Efficient trifluoromethylation via the cyclopropanation of allenes and subsequent C–C bond cleavage

Trifluoromethyl has been efficiently incorporated into organic skeletons via allene cyclization and C–C bond cleavage.

Cobalt salt-catalyzed carbocyclization reactions of α-bromo-N-phenylacetamide derivatives

A Co(ii)-catalyzed carbocyclization reaction for the synthesis of 4-substituted quinolin-2-(1H)-ones is described.

CuBr-mediated radical cascade difluoroacetamidation of acrylamides using α,α-difluoro-α-(TMS)-acetamides

Radical cascade difluoroacetamidation of N-(arylsulfonyl)acrylamides with α,α-difluoro-α-(TMS)-acetamides has been achieved for the first time.

Copper-catalyzed gem-difluoromethylenation of C(sp2)–H bonds of alkenes

Copper-catalyzed gem-difluoromethylenation of the C(sp²)–H bonds of alkenes has been developed. This protocol is the first to efficiently achieve gem-difluoromethylenation of C(sp²)–H bonds of unactivated aliphatic terminal olefins and is applied in gem-difluoromethylenation/cyclization of alkenes.

Palladium-catalyzed radical cascade difluoroalkylation/cyclization of acrylamide with ethyl difluorobromoacetate

An efficient Pd(0)-catalyzed radical cascade difluoroalkylation/cyclization of acrylamide with ethyl difluorobromoacetate was described.

A general photoinduced electron transfer-directed chemoselective perfluoroalkylation of N,N-dialkylhydrazones

The first metal-free, initiator-free, and general photochemical perfluoroalkylation of a variety of N,N-dialkylhydrazones was developed at room temperature in the absence of any external photocatalyst.

Cu-catalyzed hydrofluoroacetylation of alkynes or alkynyl carboxylic acids leading highly stereoselectively to fluoroacetylated alkenes

A copper-catalyzed hydrofluoroacetylation of arylacetylenes or alkynyl carboxylic acids with bromofluoroacetates was developed. The reaction shows excellent stereoselectivity to afford fluoroacetylated alkenes in good to excellent yields with a broad substrate scope.

Iron-catalyzed trifluoromethylation of vinylcyclopropanes: facile synthesis of CF3–containing dihydronaphthalene derivatives

FeCl₂-catalyzed trifluoromethylation of vinylcyclopropanes to generate a series of CF₃-containing dihydronaphthalene derivatives in moderate to high yields (up to 96%) under mild reaction conditions was successfully developed.

Palladium-catalyzed cascade cyclization of allylamine-tethered alkylidenecyclopropanes: facile access to iodine/difluoromethylene- and perfluoroalkyl-containing 1-benzazepine scaffolds

Palladium-catalyzed radical cascade iododifluoromethylation and iodoperfluoroalkyation/cyclization of allylamine-tethered alkylidenecyclopropanes (ACPs) were developed.

Efficient generation of perfluoroalkyl radicals from sodium perfluoroalkanesulfinates and a hypervalent iodine(iii) reagent: mild, metal-free synthesis of perfluoroalkylated organic molecules

Introduction of perfluoroalkyl groups into various organic molecules was achieved from sodium perfluoroalkanesulfinates and a hypervalent iodine(iii) reagent.

Merging photoredox with copper catalysis: decarboxylative difluoroacetylation of α,β-unsaturated carboxylic acids with ICF2CO2Et

A novel decarboxylative difluoroacetylation of α,β-unsaturated carboxylic acids via a combination of visible light photocatalysis and cooper catalysis is reported.

Palladium-catalyzed phosphonyldifluoromethylation of alkenes with bromodifluoromethylphosphonate

An efficient palladium-catalyzed phosphonyldifluoromethylation of alkenes with bromodifluoromethylphosophonate is described. The method provides a facile access to a series of phosphonyldifluoromethylated alkenes that are of interest in medicinal chemistry. Mechanistic studies reveal that a phosphonyl difluouromethyl radical is involved in the reaction.

A Visible-Light-Mediated Radical Smiles Rearrangement and its Application to the Synthesis of a Difluoro-Substituted Spirocyclic ORL-1 Antagonist

A visible-light-mediated radical Smiles rearrangement has been developed to address the challenging synthesis of the gem-difluoro group present in an opioid receptor-like 1 (ORL-1) antagonist that is currently in development for the treatment of depression and/or obesity. This method enables the direct and efficient introduction of the difluoroethanol motif into a range of aryl and heteroaryl systems, representing a new disconnection for the synthesis of this versatile moiety. When applied to the target compound, the photochemical step could be conducted on 15 g scale using industrially relevant [Ru(bpy)3Cl2] catalyst loadings of 0.01 mol %. This transformation is part of an overall five-step route to the antagonist that compares favorably to the current synthetic sequence and demonstrates, in this specific case, a clear strategic benefit of photocatalysis.

Mono-Oxidation of Bidentate Bis-phosphines in Catalyst Activation: Kinetic and Mechanistic Studies of a Pd/Xantphos-Catalyzed C-H Functionalization

Kinetic, spectroscopic, crystallographic, and computational studies probing a Pd-catalyzed C-H arylation reaction reveal that mono-oxidation of the bis-phosphine ligand is critical for the formation of the active catalyst. The bis-phosphine mono-oxide is shown to be a hemilabile, bidentate ligand for palladium. Isolation of the oxidative addition adduct, with structural elucidation by X-ray analysis, showed that the mono-oxide was catalytically competent, giving the same reaction rate in the productive reaction as the Pd(II)/xantphos precursor. A dual role for the carboxylate base in both catalyst activation and reaction turnover was demonstrated, along with the inhibiting effect of excess phosphine ligand. The generality of the role of phosphine mono-oxide complexes in Pd-catalyzed coupling processes is discussed.