Fluorinated Vinylsilanes from the Copper-Catalyzed Defluorosilylation of Fluoroalkene Feedstocks

Defluorination of HFCs by a magnesium reagent

Reaction of a series of HFCs with a main group reagent containing a Mg-Mg bond results in defluorination to form the corresponding magnesium fluoride complex. In the case of 1,1,1,2-tetrafluoroethane (HFC-134a) generation of the fluoride occurs alongside selective formation of 1,1-difluoroethene. DFT calculations have been carried out to better understand the selectivity and compare the barriers for sp3 C-F bond activation with sp3 C-H bond activation in this system.

Synthetic Advantages of Defluorinative C-F Bond Functionalization

Much progress has been made in the development of methods to both create compounds that contain C-F bonds and to functionalize C-F bonds. As such, C-F bonds are becoming common and versatile synthetic functional handles. This review summarizes the advantages of defluorinative functionalization reactions for small molecule synthesis. The coverage is organized by the type of carbon framework the fluorine is attached to for mono- and polyfluorinated motifs. The main challenges, opportunities and advances of defluorinative functionalization are discussed for each class of organofluorine. Most of the text focuses on case studies that illustrate how defluorofunctionalization can improve routes to synthetic targets or how the properties of C-F bonds enable unique mechanisms and reactions. The broader goal is to showcase the opportunities for incorporating and exploiting C-F bonds in the design of synthetic routes, improvement of specific reactions and advent of new methods.

N-Heterocyclic Carbenes with Polyfluorinated Groups at the 4- and 5-Positions from [3 + 2] Cycloadditions between Formamidinates and cis-1,2-Difluoroalkene Derivatives

We herein report the formation of fluorinated N-heterocyclic carbenes (NHCFs) that bear fluorine atoms at the 4- and 5-positions of the imidazol-2-ylidene ring. Treatment of sodium N,N'-bis(aryl)formamidinates with tetrafluoroethylene followed by the addition of LiBF4 induced a [3 + 2] cycloaddition to afford 4,5-difluorinated imidazolium salts, which served as the precursors for 4,5-difluorinated NHCs. A key feature of this procedure is its applicability to other perfluorinated compounds, which enabled us to incorporate polyfluorinated functional groups at 4- and 5-positions on the imidazol-2-ylidene skeleton. Thus, employing octafluorocyclopentene and hexafluorobenzene led to the formation of 4,4,5,5,6,6-hexafluoro-1,3-diaryl-3,4,5,6-tetrahydrocyclopenta[d]imidazolium (CypIPrF·HBF4) and 4,5,6,7-tetrafluoro-1,3-diarylbenzimidazolium (BIPrF·HBF4) salts, respectively. A thorough NMR analysis of these NHCFs, their selenium adducts, and their tricarbonyl nickel complexes, (NHCF)Ni(CO)3, demonstrated that the fluorine substituents, contrary to expectations, tend to act as electron donors owing to the considerable positive mesomeric effect, while the perfluorocyclopentene-fused and tetrafluorobenzo-fused rings are pure electron acceptors due to their strong negative inductive effect. The unique and increased π-accepting character of the perfluorocyclopentene-fused and tetrafluorobenzo-fused NHCFs in both stoichiometric and catalytic reactions is further demonstrated by employing (NHCF)Ni(CO)3 and (NHCF)AuCl species, respectively. Moreover, an analysis of the % buried volume (%Vbur) values clearly suggests that the modification of the NHC backbone with polyfluorinated groups can drastically alter the electronic properties of the NHC ligand without substantially changing its steric properties. Our experimental results were further corroborated by a series of computational calculations.

Synthesis and Transformation of Bis(silyl)-Substituted Conjugated Vinylallene Compounds

We develop a copper-catalyzed disilylation of polysubstituted pent-1-en-4-yn-3-yl acetate derivatives, which in one pot furnishes the bis(silyl)-substituted vinylallenes in moderate yields under mild reaction conditions. The reaction shows broad substrate scope and single stereoselectivity. Besides, we develop a method to decrease the electrocyclization temperature of vinylallenes for the synthesis of methylenecyclobutenes by installing bis(silyl) substituents. And the effect of a silyl substituent on electrocyclization of vinylallenes was studied via DFT computation. The synthetic method features broad substrate scope and excellent stereoselectivity.

Base-Mediated α-gem-Difluoroalkenylations of Aldehydes and Ketones

Herein, we present a base-mediated nucleophilic substitution reaction of α-trifluoromethylstyrenes with simple silyl enol ethers, enabling the efficient synthesis of carbonyl-substituted gem-difluoroalkenes. The merit of this protocol is exhibited by its mild reaction conditions, broad substrate scope, and scalable preparation. Notably, this method demonstrates its applicability for late-stage functionalization of structurally complex molecules. Moreover, we illustrate that the resulting products can serve as valuable precursors for the synthesis of diverse medicinally relevant compounds.

Nickel-Catalyzed Selective C(sp2 )-F Bond Alkylation of Industrially Relevant Hydrofluoroolefin HFO-1234yf

The selective transition-metal catalyzed C-F bond functionalization of inexpensive industrial fluorochemicals represents one of the most attractive approaches to valuable fluorinated compounds. However, the selective C(sp2 )-F bond carbofunctionalization of refrigerant hydrofluoroolefins (HFOs) remains challenging. Here, we report a nickel-catalyzed selective C(sp2 )-F bond alkylation of HFO-1234yf with alkylzinc reagents. The resulting 2-trifluoromethylalkenes can serve as a versatile synthon for diversified transformations, including the anti-Markovnikov type hydroalkylation and the synthesis of bioactive molecule analogues. Mechanistic studies reveal that lithium salt is essential to promote the oxidative addition of Ni0 (Ln ) to the C-F bond; the less electron-rich N-based ligands, such as bipyridine and pyridine-oxazoline, feature comparable or even higher oxidative addition rates than the electron-rich phosphine ligands; the strong σ-donating phosphine ligands, such as PMe3 , are detrimental to transmetallation, but the less electron-rich and bulky N-based ligands, such as pyridine-oxazoline, facilitate transmetallation and reductive elimination to form the final product.

Copper and Palladium Cocatalyzed Defluorinative Coupling of gem-Difluoroalkenes and Acyl Chloride

A novel copper and palladium cocatalyzed defluorinative coupling of gem-difluoroalkenes and acyl chlorides has been developed. It is a practical method to prepare α-fluorochalcones, which are a kind of important unit in a variety of bioactive compounds. Under mild reaction conditions, a series of substrates with various functional groups could afford desired products smoothly. Further synthetic studies illustrated that the products of this chemistry could be used as versatile precursors to access complicated compounds. Furthermore, the reaction mechanism was proposed based on control experiments.

Photoredox Catalyzed Single C-F Bond Activation of Trifluoromethyl Ketones: A Solvent Controlled Divergent Access of gem-Difluoromethylene Containing Scaffolds

Selective defluorinative functionalization of trifluoromethyl ketones is a long-standing challenge owing to the exhaustive mode of the process. To meet the demands for the installation of the gem-difluoromethylene unit for the construction of the molecular architectures of well-known pharmaceuticals and agrochemicals, a distinct pathway is thereby highly desirable. Here, a protocol is introduced that allows the divergent synthesis of gem-difluoromethylene group containing tetrahydrofuran derivatives and linear ketones via single C-F bond activation of trifluoromethyl ketones using visible-light photoredox catalysis in the presence of suitable olefins as trapping partner. The choice of appropriate solvent and catalyst plays a significant role in controlling the divergent behavior of this protocol. Highly reducing photo-excited catalysts are found to be responsible for the generation of α,α-difluoromethyl ketone (DFMK) radicals as the key intermediate via a SET process. This protocol also results in a high diastereoselectivity towards the formation of partially fluorinated cyclic ketal derivatives with simultaneous construction of one C-C and two C-O bonds. State-of-the-art DFT calculations are performed to address the origin of diastereoselectivity as well as the divergence of this protocol.

Nickel-Catalyzed Reductive Coupling of Chlorosilanes

Organosilanes play essential roles in many important research areas. The use of readily available chlorosilanes to catalytically access these compounds is synthetically appealing but remains a long-standing challenge. Nickel-catalyzed reductive cross-coupling reaction has recently emerged as a promising protocol to arrive at this goal. This strategy allows the chlorosilanes to be coupled with various carbon electrophiles under mild conditions. These reactions afford organosilanes with improved molecular diversity, structural complexity, and functional group compatibility. This Concept article summarizes the recent advance on nickel-catalyzed reductive C-Si couplings of chlorosilanes.

Cu-catalyzed cascade difluoroalkylation/5-endo cyclization/β-fluorine cleavage of ynones

A copper-catalyzed, redox-neutral cascade difluoroalkylation/5-endo annulation/β-fluorine cleavage of ynones is developed, providing a direct and stereoselective method to access synthetically important α-monofluoroalkenyl cyclopentanones. Mechanistic studies suggest an unprecedented Cu^II-assisted β-fluorine fragmentation, which may be valuable for the challenging but important C-F bond activation. Moreover, the in situ generated difluorocarbene was found to serve as an effective reductant for the regeneration of copper(I) catalyst, thus avoiding the addition of external reductants.

Recent Advances in Alkenyl sp2 C-H and C-F Bond Functionalizations: Scope, Mechanism, and Applications

Alkenes and their derivatives are featured widely in a variety of natural products, pharmaceuticals, and advanced materials. Significant efforts have been made toward the development of new and practical methods to access this important class of compounds by selectively activating the alkenyl C(sp²)-H bonds in recent years. In this comprehensive review, we describe the state-of-the-art strategies for the direct functionalization of alkenyl sp² C-H and C-F bonds until June 2022. Moreover, metal-free, photoredox, and electrochemical strategies are also covered. For clarity, this review has been divided into two parts; the first part focuses on currently available alkenyl sp² C-H functionalization methods using different alkene derivatives as the starting materials, and the second part describes the alkenyl sp² C-F bond functionalization using easily accessible gem-difluoroalkenes as the starting material. This review includes the scope, limitations, mechanistic studies, stereoselective control (using directing groups as well as metal-migration strategies), and their applications to complex molecule synthesis where appropriate. Overall, this comprehensive review aims to document the considerable advancements, current status, and emerging work by critically summarizing the contributions of researchers working in this fascinating area and is expected to stimulate novel, innovative, and broadly applicable strategies for alkenyl sp² C-H and C-F bond functionalizations in the coming years.

Electrochemical Synthesis of gem-Difluoro- and γ-Fluoro-Allyl Boronates and Silanes

The electrochemical synthesis of fluorinated allyl silanes and boronates was disclosed. The addition of electrogenerated boryl or silyl radicals onto many α-trifluoromethyl or α-difluoromethylstyrenes in an undivided cell allowed the formation of a large panel of synthetically useful gem-difluoro and γ-fluoroallyl boronates and silanes (64 examples, from 31 % to 95 % yield). In addition, a scale up of the reactions under continuous flow was showcased using an electrochemical reactor with promising volumetric productivity (688 g.L-1 .h-1 and 496 g.L-1 .h-1 ). Moreover, the synthetic utility of these building blocks was highlighted through versatile transformations. Finally, plausible reaction mechanisms were suggested to explain the formation of the products.

Cu(II)-Catalyzed Unsymmetrical Dioxidation of gem-Difluoroalkenes to Generate α,α-Difluorinated-α-phenoxyketones

A Cu-based catalyst system convergently couples gem-difluoroalkenes with phenols under aerobic conditions to deliver α,α-difluorinated-α-phenoxyketones, an unstudied hybrid fluorinated functional group. Composed of α,α-difluorinated ketone and α,α-difluorinated ether moieties, these compounds have rarely been reported as a synthetic intermediate. Computational predictions and later experimental corroboration suggest that the phenoxy-substituted fluorinated ketone's sp3-hybridized hydrate form is energetically favored relative to the respective nonether variant and that perturbation of the electronic character of the ketone can further encourage the formation of the hydrate. The more facile conversion between ketone and hydrate forms suggests that analogues should readily covalently inhibit proteases and other enzymes. Further functionalization of the ketone group enables access to other useful fluorinated functional groups.

Photoredox Metal-Free Allylic Defluorinative Silylation of α-Trifluoromethylstyrenes with Hydrosilanes

We report an efficient strategy that combines organic photoredox and hydrogen atom transfer to deliver gem-difluoroallylsilanes via defluorinative silylation of α-trifluoromethylstyrenes using hydrosilanes as silicon sources. This protocol provides an environmentally friendly approach for the preparation of structurally diverse gem-difluoroallylsilanes with excellent functional group compatibility and renders it suitable for late-stage modification of bioactive and complex molecules.

Oxidative Addition of Silicon-Chloride Bonds to a Zerovalent Ruthenium Center and Direct Generation of an Ethylene Insertion Complex

The oxidative addition of a silicon-chloride (Si-Cl) bond to a metal center can be a key reaction step in coordinative silicon chemistry, but this reaction is seldom observed. Herein, we report direct oxidative addition of the Si-Cl bonds of dimethyldichlorosilane (Me₂SiCl₂) and cyclotrimethylenedichlorosilane [(CH₂)₃SiCl₂] to low-valent ruthenium complexes, yielding the 16e^- chloro(organosilyl)ruthenium complexes [N₃]Ru(Cl)(SiMe₂Cl) (4a) and [N₃]Ru(Cl)(SiCl(CH₂)₃) (4b) ([N₃] = 2,6-(MesN═CMe)₂C₅H₃N; Mes = 1,3,5-trimethylphenyl; Me = methyl). The reversible reaction of 4a with ethylene yields an 18e^- ethylene adduct, in which an ethylene is subsequently inserted into a ruthenium-silicon (Ru-Si) bond to produce the 16e^- complex [N₃]Ru(Cl)(CH₂CH₂SiMe₂Cl) (7). This study provides a good example of the direct generation of an ethylene insertion product, which is an important intermediate in the catalytic reduction of unsaturated molecules.

Nickel-catalyzed alkyl-arylation of 3,3,3-trifluoropropene

Owing to the versatile synthetic utility of its carbon-carbon double bond, low-cost industrial chemical 3,3,3-trifluoropropene (TFP) represents one of the most straightforward and cost-efficient precursors to prepare trifluoromethylated compounds. However, only limited methods for the efficient transformations of TFP have been reported so far. Here, we report a nickel-catalyzed dicarbofunctionalization of TFP. The reaction uses inexpensive NiCl₂·6H₂O as the catalyst and 4,4'-biMeO-bpy and PCy₂Ph as the ligands, allowing the alkyl-arylation of TFP with a variety of tertiary alkyl iodides and arylzinc reagents in high efficiency. This nickel-catalyzed process overcomes the previous challenges by suppressing β-H and β-F eliminations from TFP, rendering this strategy effective for the transformations of TFP into medicinal interest trifluoromethylated compounds.

Recent Advances in the Construction of Fluorinated Organoboron Compounds

Fluorinated organoboron compounds are important synthetic building blocks that combine the unique characteristics of a fluorinated motif with the versatile synthetic applications of organoboron moiety. This review article guides the research on fluorinated organoboron compounds mainly from four aspects in recent years: selective monodefluoroborylation of polyfluoroarenes and polyfluoroalkenes, selective borylation of fluorinated substrates, selective fluorination of organoboron compounds, and borofluorination of alkynes/olefins. In addition, this review will provide a necessary guidance and inspiration for the research on the valuable synthetic building block fluorinated organoboron compounds.

Chemo- and regio-divergent access to fluorinated 1-alkyl and 1-acyl triazenes from alkynyl triazenes

The 1,1,2,2-tetrafluoroethylene unit is a prevalent pattern in bioactive molecules and functional materials. Despite being in principle a straightforward strategy to access this motif, the direct tetrafluorination of alkynes involves...

Nickel-Catalyzed Stereo- and Enantioselective Cross-Coupling of gem-Difluoroalkenes with Carbon Electrophiles by C-F Bond Activation

Stereo- and enantioselective cross-electrophile coupling involving C-F bond activation is reported. Treatment of gem-difluoroalkenes with racemic benzyl electrophiles in the presence of a chiral nickel complex using B₂ pin₂ as a stoichiometric reductant allows the construction of a C(sp² )-C(sp³ ) bond under mild conditions, affording a broad range of monofluoroalkenes bearing stereogenic allylic centers. Initial mechanistic studies indicate that a radical chain pathway may be operating, wherein the ester group in the gem-difluoroalkene promotes C-F bond activation through oxidative addition to a Ni species.

Application of Industrially Relevant HydroFluoroOlefin (HFO) Gases in Organic Syntheses

Hydrofluoroolefin (HFO) gases are state-of-the-art cooling agents with widespread household and industrial applications. Considering their structural benefits these fluorous feedstocks have gained the attention of organic chemists in the last couple of years. In this short review we summarized the existing synthetic transformations of these gaseous starting material and present their applicability in the synthesis of fluorine-containing organic molecules, which have potential importance as building blocks and reagents for diverse syntheses.

1 Introduction

2 Addition Reactions

3 Substitutions

4 Organometallic Chemistry

4.1 Organolithium Compounds

4.2 Organometallic Complexes

4.3 Silicon Organic Chemistry

4.4 Boron Organic Chemistry

4.5 Palladium-Catalyzed Transformations

4.6 Metathesis

4.7 Hydroesterification, Hydroformylation

5 Conclusions

HFIP-Assisted Single C-F Bond Activation of Trifluoromethyl Ketones using Visible-Light Photoredox Catalysis

A visible light photoredox catalytic method for the selective cleavage of single strong C-F bond in trifluoromethyl ketones is reported. Single electron reduction of trifluoromethyl ketones generates difluoromethyl radicals which can be engaged in intermolecular C-C bond formation with N-methyl-N-arylmethacrylamides to furnish fluorine-containing oxindole derivatives in good yields. The reaction shows excellent chemoselectivity with good functional group tolerance under mild conditions. 1,1,1,3,3,3-Hexafluoroisopropanol (HFIP) as a solvent plays a critical role for the selective single C-F bond cleavage. High-level DFT calculations are depicted to shed light on the mechanism.

Advances in silylation and borylation of fluoroarenes and gem-difluoroalkenes via C-F bond cleavage

Organoboron and organosilane compounds are widely used in organic synthesis and pharmaceuticals. In addition, the C-F bond functionalization is a useful tool for the construction of carbon-carbon and carbon-heteroatom bonds. In particular, the late-stage functionalization of bioactive molecules through defluoroborylation and defluorosilylation reactions will provide good opportunities for the development and diversification of new medicinal compounds. Thus, this feature article summarized the methods for the defluorosilylation and defluoroborylation of unreactive monofluoroarenes and gem-difluoroalkenes from 2000 to 2021, which might create some new ideas and will be helpful for further research in this field. These defluoroborylation and defluorosilylation strategies can be applied to synthesize silylated arenes, borylated arenes, silylated fluoroalkenes, and borylated fluoroalkenes, thus providing impressive advantages over traditional methods for the synthesis of organoboron and organosilane compounds in terms of divergent structures.

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.

Generation of Axially Chiral Fluoroallenes through a Copper-Catalyzed Enantioselective β-Fluoride Elimination

Herein we report the copper-catalyzed silylation of propargylic difluorides to generate axially chiral, tetrasubstituted monofluoroallenes in both good yields (27 examples >80%) and enantioselectivities (82-98% ee). Compared to previously reported synthetic routes to axially chiral allenes (ACAs) from prochiral substrates, a mechanistically distinct reaction has been developed: the enantiodiscrimination between enantiotopic fluorides to set an axial stereocenter. DFT calculations and vibrational circular dichroism (VCD) suggest that β-fluoride elimination from an alkenyl copper intermediate likely proceeds through a syn-β-fluoride elimination pathway rather than an anti-elimination pathway. The effects of the C1-symmetric Josiphos-derived ligand on reactivity and enantioselectivity were investigated. Not only does this report showcase that alkenyl copper species (like their alkyl counterparts) can undergo β-fluoride elimination, but this elimination can be achieved in an enantioselective fashion.

Versatile Reaction Pathways of 1,1,3,3,3-Pentafluoropropene at Rh(I) Complexes [Rh(E)(PEt3 )3 ] (E=H, GePh3 , Si(OEt)3 , F, Cl): C-F versus C-H Bond Activation Steps

The reaction of the rhodium(I) complexes [Rh(E)(PEt₃)₃] (E=GePh₃ (1), H (6), F (7)) with 1,1,3,3,3‐pentafluoropropene afforded the defluorinative germylation products Z/E‐2‐(triphenylgermyl)‐1,3,3,3‐tetrafluoropropene and the fluorido complex [Rh(F)(CF₃CHCF₂)(PEt₃)₂] (2) together with the fluorophosphorane E‐(CF₃)CH=CF(PFEt₃). For [Rh(Si(OEt)₃)(PEt₃)₃] (4) the coordination of the fluoroolefin was found to give [Rh{Si(OEt)₃}(CF₃CHCF₂)(PEt₃)₂] (5). Two equivalents of complex 2 reacted further by C−F bond oxidative addition to yield [Rh(CF=CHCF₃)(PEt₃)₂(μ‐F)₃Rh(CF₃CHCF₂)(PEt₃)] (9). The role of the fluorido ligand on the reactivity of complex 2 was assessed by comparison with the analogous chlorido complex. The use of complexes 1, 4 and 6 as catalysts for the derivatization of 1,1,3,3,3‐pentafluoropropene provided products, which were generated by hydrodefluorination, hydrometallation and germylation reactions.

Synthesis and Photochemical Application of Hydrofluoroolefin (HFO) Based Fluoroalkyl Building Block

A novel fluoroalkyl iodide was synthesized on multigram scale from refrigerant gas HFO-1234yf as cheap industrial starting material in a simple, solvent-free, and easily scalable process. We demonstrated its applicability in a metal-free photocatalytic ATRA reaction to synthesize valuable fluoroalkylated vinyl iodides and proved the straightforward transformability of the products in cross-coupling chemistry to obtain conjugated systems.

Silylative aromatization of p-quinone methides under metal and solvent free conditions

A base-mediated silylation reaction leading to benzyl silanes has been developed. Under transition-metal and solvent free conditions, the silylation of a wide array of p-quinone methides is achieved using a Cs₂CO₃ catalyst in yields up to 96%. Carboxylation of the as-obtained organosilane with gaseous CO₂ provides a new synthetic protocol for the preparation of carboxylic acid.

A novel and efficient synthetic protocol is reported for the synthesis of benzyl silanes from readily available silylborane and p-quinone methides using 5% cesium carbonate under solvent-free conditions.

Copper-Catalyzed Chemoselective Silylative Cyclization of 2,2'-Diethynylbiaryl Derivatives

In this protocol, copper-catalyzed diverse silylative carbocyclization reactions of 2,2'-diethynylbiaryl derivatives with silaboronate were reported. Three new and novel types of domino reactions for the copper-catalyzed transformation of silaboronate were discovered. The corresponding cyclobuta[l]phenanthrene, bis((silyl)methyl)phenanthrene, and silyl-substituted exocyclic diene products were chemoselectively formed with high efficiency.

Synthesis of Fluoroalkyl Sulfides via Additive-Free Hydrothiolation and Sequential Functionalization Reactions

A modular synthetic method, involving a hydrothiolation, silylation, and fluoroalkylation, for the construction of highly functionalized fluoroalkyl sulfides has been developed. The use of aprotic polar solvents enables the additive-free chemoselective hydrothiolation of tetrafluoroethylene, trifluorochloroethylene, and hexafluoropropene with various thiols. The stepwise functionalization reactions convert the hydrothiolated intermediates into the tetrafluoroethyl sulfides in high efficiency. The method avoids the use of the environmental pollutant Halon-2402, which was employed as a building block in a reported synthetic route.

Experimental and Computational Studies of the Iron-Catalyzed Selective and Controllable Defluorosilylation of Unactivated Aliphatic gem-Difluoroalkenes

The first iron-catalyzed defluorosilylation of unactivated gem-difluoroalkenes was developed, delivering gem-disilylated alkenes and (E)-silylated alkenes with excellent efficiency. This protocol features good functional group compatibility and excellent regio- and stereoselectivity, enabling the late-stage silylation of biologically relevant compounds, thus providing good opportunities for applications in medicinal chemistry. Preliminary mechanistic studies and DFT calculations reveal that a nucleophilic addition and elimination of the second C-F bond might be involved in the disilylation catalytic system, demonstrating unusual reactivity characteristics of iron catalysis.

Activation of the Si–B interelement bond related to catalysis

Covering the past seven years, this review comprehensively summarises the latest progress in the preparation and application of Si–B reagents, including the discussion of relevant reaction mechanisms.

One pot synthesis of isocyano-containing, densely functionalised gem-difluoroalkenes from α-trifluoromethyl alkenes, alkyl halides and TosMIC

A base-promoted one-pot, three-component reaction of TosMIC with α-trifluoromethyl alkenes and alkyl halides has been deveolped for the synthesis of isocyano-containing, densely functionalised gem-difluoroalkenes.

Two C(sp3)-F Bond Activation in a CF3 Group: ipso-Defluorinative Amination Triggered 1,3-Diamination of (Trifluoromethyl)alkenes with Indoles, Carbazoles, Pyrroles, and Sulfonamides

A novel strategy enabled cleavage of two C(sp³)-F bonds in a CF₃ group is reported. Triggered by ipso-defluorinative amination, this 1,3-diamination of (trifluoromethyl)alkenes with indoles, carbazoles, pyrroles, and sulfonamides gave acyclic 1,3-diamine products bearing a monofluoroalkene moiety in high yields with good to excellent Z/E selectivities. Preliminary mechanistic studies enable the isolation of the reaction intermediate and indicate that a unique sequential ipso-/γ-selective defluorinative amination pathway is involved in this transformation.