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Upstream product

• 645-00-1 m-iodonitrobenzene 
• 2925-16-8 1,1-difluoro-2-iodoethylene 
• 1219454-89-3 2-((difluoromethyl)sulfonyl)pyridine 
• 99-61-6 3-nitro-benzaldehyde 
• 1535-65-5 difluoromethyl phenyl sulfone 
• 87189-16-0 potassium 2-bromo-2,2-difluoroacetate 
• 1600503-70-5 potassium 2-pyridinyl sulfonyl-difluoroacetate 
• 1895-39-2 sodium chlorodifluoroacetate 
• 75-61-6 dibromodifluoromethane 
• 123266-30-8 2,2-difluoroethenyltri-n-butylstannane 
• 3718-22-7 3-nitrobenzaldehyde hydrazone 
• 19740-19-3 chlorodifluoroacetic acid lithium salt 

Downstream Products

• 114980-30-2 1-(2,2,2-trifluoroethyl)-3-nitrobenzene 
• 621-50-1 (3-nitrophenyl)acetonitrile 

Relevant academic research and scientific papers

Acid-Catalyzed Hydrothiolation of gem-Difluorostyrenes to Access α,α-Difluoroalkylthioethers

The substitution of hydrogen atoms with fluorine in bioactive molecules can greatly impact physicochemical, pharmacokinetic, and pharmacodynamic properties. However, current synthetic methods cannot readily access many fluorinated motifs, which impedes utilization of these groups. Thus, the development of new methods to introduce fluorinated functional groups is critical for developing the next generation of biological probes and therapeutic agents. The synthesis of one such substructure, the α,α-difluoroalkylthioether, typically requires specialized conditions that necessitate early-stage installation. A late-stage and convergent approach to access α,α-difluoroalkylthioethers could involve nucleophilic addition of thiols across gem-difluorostyrenes. Unfortunately, under basic conditions, nucleophilic addition to gem-difluorostyrenes generates an anionic intermediate that can undergo facile elimination of fluoride to generate α-fluorovinylthioethers. To overcome this decomposition, we herein exploit an acid-based catalyst system to facilitate simultaneous nucleophilic addition and protonation of the unstable intermediate. Ultimately, the optimized mild conditions afford the desired α,α-difluoroalkylthioethers in high selectivity and moderate to excellent yields. These α,α-difluoroalkylthioethers are less nucleophilic and more oxidatively stable relative to nonfluorinated thioethers, suggesting the potential application of this unexplored functional group in biological probes and therapeutic agents.

Asymmetric Synthesis of 2,2-Difluorotetrahydrofurans through Palladium-Catalyzed Formal [3+2] Cycloaddition

The asymmetric synthesis of 2,2-difluorinated tetrahydrofurans was accomplished via enantioselective formal [3+2] cycloaddition catalyzed by palladium. The asymmetric reaction between gem-difluoroalkenes and racemic vinyl epoxides or vinylethylene carbonates resulted in the formation of enantioenriched 2,2-difluorotetrahydrofurans with an enantioselectivity up to 98 %. Notably, the reaction used the readily available (R)-BINAP as the ligand at a low loading and yielded a wide variety of difluorinated products in moderate to high yields. Both chiral diastereomers could be obtained in a single sequence.

Design and Synthesis of TY-Phos and Application in Palladium-Catalyzed Enantioselective Fluoroarylation of gem-Difluoroalkenes

The first example of highly enantioselective fluoroarylation of gem-difluoroalkenes with aryl halides is presented by using a new chiral sulfinamide phosphine (Sadphos) type ligand TY-Phos. N-Me-TY-Phos can be easily synthesized on a gram scale from readily available starting materials in three steps. Salient features of this work including readily available starting materials, good yields, high enantioselectivities as well as broad substrate scope make this approach very practical and attractive. Notably, the asymmetric synthesis of an analogue of a biologically active molecule is also reported.

Organocatalytic strategy for hydrophenolation of gem-difluoroalkenes

Gem-difluoroalkenes are an easily accessed fluorinated functional group, and a useful intermediate for elaborating into more complex fluorinated compounds. Currently, most functionalization reactions of gem-difluoroalkenes, with or without a transition metal-based catalyst system, involve the addition or removal of a fluorine atom to generate trifluorinated or monofluorinated products, respectively. In contrast, we present a complementary “fluorine-retentive” reaction that exploits an organocatalytic strategy to add phenols across gem-difluoroalkenes to deliver β,β-difluorophenethyl arylethers. The products are produced in good to moderate yields and selectivities, thus providing a range of compounds that are underrepresented in the synthetic and medicinal chemistry literature.

Photoredox-Coupled F-Nucleophilic Addition: Allylation of gem-Difluoroalkenes

A novel strategy for the expedient construction of CF3-embeded tertiary/quarternary carbon centers was developed by taking advantage of photoredox catalysis. Thanks to a key step of single-electron oxidation, electron-rich gem-difluoroalkenes, which otherwise are essentially reluctant towards F-nucleoplilic addition, now readily participate in this fluoroallylation reaction. Furthermore, this strategy provides an elegant example for the generation, as well as functionalization, of α-CF3-substituted benzylic radical intermediates using cheap and readily available starting materials.

Rhodium-Catalyzed Defluorinative Vinylation of gem-Difluoroalkenes for the Synthesis of 2-Fluoro-1,3-dienes

Herein, we present a strategy for the formation of 2-fluoro-1,3-diene derivatives via rhodium-catalyzed direct C(sp2)—C(sp2) cross-coupling of gem-difluoroalkenes and acrylamides. By merging Rh(III)-catalyzed C(sp2)–H bond activation and nucleophilic addition/F-elimination of gem-difluoroalkene, an efficient defluorinative vinylation reaction is uncovered, which leads to the generation of 2-fluoro-1,3-dienes in moderate to good yields with excellent stereoselectivity under mild conditions. Preliminary mechanistic study suggests unique effects of fluorine substituents which allow the reactivity profile not observed with the congeners bearing heavier halides.

Base Catalysis Enables Access to α,α-Difluoroalkylthioethers

A nucleophilic addition reaction of aryl thiols to readily available β,β-difluorostyrenes provides α,α-difluoroalkylthioethers. The reaction proceeds through an unstable anionic intermediate, prone to eliminate fluoride and generate α-fluorovinylthioethers. However, the use of base catalysis overcomes the facile β-fluoride elimination, generating α,α-difluoroalkylthioethers in excellent yields and selectivities.

Synthesis of tetrazines from: Gem -difluoroalkenes under aerobic conditions at room temperature

An efficient and green procedure for the synthesis of tetrazines has been developed based on an old chemistry reported by Carboni in 1958. Both symmetric and asymmetric 3,6-disubstituted 1,2,4,5-tetrazines can be obtained in moderate to high yields from t

Palladium-Catalyzed Fluoroarylation of gem-Difluoroalkenes

A Pd-catalyzed fluoroarylation of gem-difluoroalkenes with aryl halides is reported. By taking advantage of the in situ generated α-CF3-benzylsilver intermediates derived from the nucleophilic addition of silver fluoride to gem-difluoroalkenes, this strategy bypasses the use of a strong base, thus enabling a mild and general synthetic method for ready access to non-symmetric α,α-disubstituted trifluoroethane derivatives.

Palladium-Catalyzed Defluorinative Coupling of 1-Aryl-2,2-Difluoroalkenes and Boronic Acids: Stereoselective Synthesis of Monofluorostilbenes

The palladium-catalyzed defluorinative coupling of 1-aryl-2,2-difluoroalkenes with boronic acids is described. Broad functional-group tolerance arises from a redox-neutral process by a palladium(II) active species which is proposed to undergo a β-fluoride elimination to afford the products. The monofluorostilbene products were formed with excellent diastereoselectivity (≥50:1) in all cases, and it is critical, as traditional chromatographic techniques often fail to separate monofluoroalkene isomers. As a demonstration of this method's unique combination of reactivity and functional-group tolerance, a Gleevec analogue, using a monofluorostilbene as an amide isostere, was synthesized.