WO2023281421A1 - Hydrofluoroolefins and uses thereof - Google Patents

Abstract

Hydrofluoroolefin amine compounds are represented by the following general formula (I): 5 (Rf 2-)(Rf 3CF2-)N-CH=CF-Rf 1 Formula I where Rf 1 is a linear, branched, or cyclic fluoroalkyl group containing 1-5 carbon atoms and may contain up to 2 H atoms, Rf 2 is a perfluorinated alkyl group, Rf 3 is a perfluorinated alkyl group, or Rf 2 and Rf 3 together form a perfluorinated ring structure, and 0 Rf 2 or Rf 3 may contain an O atom or an N atom. The hydrofluoroolefin amine compounds can be used in working fluids.

Description

HYDROFLUOROOLEFINS AND USES THEREOF Summary Disclosed herein are hydrofluoroolefin amine compounds, working fluids containing the hydrofluoroolefin amine compounds, and methods of preparing the hydrofluorolefin amine compounds. In some embodiments, the hydrofluoroolefin amine compounds are represented by the following general formula (I): (R_f ²-)(R_f ³CF₂-)N-CH=CF-R_f ¹ Formula I where R_f ¹ is a linear, branched, or cyclic fluoroalkyl group containing 1-5 carbon atoms and may contain up to 2 H atoms, Rf² is a perfluorinated alkyl group containing 1-4 carbon atoms and may contain one or more catenated heteroatoms selected from O or N, R_f ³ is a perfluorinated alkyl group containing 1-3 carbon atoms and may contain one or more catenated heteroatoms selected from O or N, or R_f ² and R_f ³ together form a perfluorinated ring structure with 3-6 carbon atoms, and may contain an O atom or a second N atom. Also disclosed herein are working fluids that comprise a hydrofluoroolefin amine compound represented by the following general formula (I) described above. The hydrofluorolefin amine compound is present in the working fluid at an amount of at least 25% by weight based on the total weight of the working fluid. Also disclosed are methods of making the hydrofluoroolefin amines, where the method comprises providing a perfluorinated precursor compound comprising a perfluorinated imine with general structure: Rf²-N=CF(-Rf³) where Rf² is a perfluorinated alkyl group containing 1-4 carbon atoms and may contain one or more catenated heteroatoms selected from O or N, Rf³ is a perfluorinated alkyl group containing 1-3 carbon atoms and may contain one or more catenated heteroatoms selected from O or N, or R_f ² and R_f ³ together form a perfluorinated ring structure with 3-6 carbon atoms, and may contain an O atom or a second N atom and reacting the perfluorinated precursor with a reaction mixture comprising a fluoride salt comprising a metal fluoride salt or a tetraalkylammonium fluoride salt, in an aprotic organic solvent, to form a fluorinated amide salt. The fluorinated amide salt is quenched with an electrophile R_f ¹ -CF₂CH₂-X where R_f ¹ is a linear, branched, or cyclic fluoroalkyl group containing 1-5 carbon atoms and may contain up to 2 H atoms, and X is -OSO₂CF₃, OSO₂CF₂CF₃, or OSO₂CF₂CF₂CF₂CF₃ to form a fluorinated compound of general Formula II: (R_f ²-)( R_f ³-CF₂-)N-CH₂CF₂-R_f ¹ II where R_f ¹ is a linear, branched, or cyclic fluoroalkyl group containing 1-5 carbon atoms and may contain up to 2 H atoms, Rf² is a perfluorinated alkyl group containing 1-4 carbon atoms and may contain one or more catenated heteroatoms selected from O or N, R_f ³ is a perfluorinated alkyl group containing 1-3 carbon atoms and may contain one or more catenated heteroatoms selected from O or N, or R_f ² and R_f ³ together form a perfluorinated ring structure with 3-6 carbon atoms, and may contain an O atom or a second N atom, and dehydrofluorination with an aqueous solution of a metal hydroxide and a phase transfer catalyst to form a hydrofluoroolefin amine of general Formula I as described above. Detailed Description There is an increasing demand for environmentally friendly and low toxicity chemical compounds for use as working fluids that meet demanding performance requirements and can be manufactured cost-effectively. The desired working fluid materials have desirable low ozone-depleting features, low global warming potential (GWP), and are thermally, hydrolytically, and base stable. At the same time the desired working fluid materials must also meet the performance requirements (e.g., nonflammability, solvency, stability, and operating temperature range) of a variety of different applications (e.g., heat transfer, solvent cleaning, deposition coating solvents, and electrolyte solvents and additives). Currently, the materials used in these applications are fluorinated fluids, such as hydrofluoroethers (HFEs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and hydrochlorofluorocarbons (HCFCs). Generally, the present disclosure provides a new class of fluorinated compounds useful as working fluids. The new fluorinated compounds are oxygen-containing hydrofluoroolefins (HFOs), which provide similar physical properties to existing fluorinated fluids, but generally provide lower atmospheric lifetimes and global warming potentials to provide a more acceptable environmental profile. The hydrofluoroolefins of this disclosure have catenated nitrogen atoms and are described in this disclosure as “hydrofluoroolefin amines”. These hydrofluoroolefin amines have the desirable combination of properties of high thermal stability, low toxicity, nonflammability, good solvency, and a wide operating temperature range to meet the requirements of various applications. The compounds also have generally low atmospheric lifetimes, are not ozone-depleting, and have low global warming potentials (GWPs). As used herein, the terms “hydrofluoroolefins” and “HFOs” are used consistent with their commonly understood chemical definitions and refer to unsaturated organic compounds comprising hydrogen, fluorine, and carbon atoms. Unlike traditional hydrofluorocarbons (HFCs) and chlorofluorocarbons (CFCs) which are saturated, HFOs are unsaturated comprising an olefin group. As used herein, “catenated heteroatom” means an atom other than carbon (for example, oxygen, nitrogen, or sulfur) that is bonded to at least two carbon atoms in a carbon chain (linear or branched or within a ring) so as to form a carbon-heteroatom- carbon linkage. As used herein, "fluoro-" (for example, in reference to a group or moiety, such as in the case of "fluoroalkylene" or "fluoroalkyl" or "fluorocarbon") or "fluorinated" means (i) partially fluorinated such that there is at least one carbon-bonded hydrogen atom, or (ii) perfluorinated. As used herein, "perfluoro-" (for example, in reference to a group or moiety, such as in the case of "perfluoroalkylene" or "perfluoroalkyl" or "perfluorocarbon") or "perfluorinated" means completely fluorinated such that, except as may be otherwise indicated, there are no carbon-bonded hydrogen atoms replaceable with fluorine. As used herein, the group “-R_f” is used according to common usage in chemical arts and refers to fluoroalkyl group. The group “-R_f -“ refers to a fluoroalkylene group. As used herein, the term “aqueous” refers to a liquid composition that includes at least water as the majority component, but may also contain minor amounts of additional water-miscible components. In some embodiments, the present disclosure is directed to hydrofluoroolefin amine compounds represented by the following general Formula I: (R_f ²-)(R_f ³CF₂-)N-CH=CF-R_f ¹ Formula I where R_f ¹ is a linear, branched, or cyclic fluoroalkyl group containing 1-5 carbon atoms and may contain up to 2 H atoms, R_f ² is a perfluorinated alkyl group containing 1-4 carbon atoms and may contain one or more catenated heteroatoms selected from O or N, R_f ³ is a perfluorinated alkyl group containing 1-3 carbon atoms and may contain one or more catenated heteroatoms selected from O or N, or R_f ² and R_f ³ together form a perfluorinated ring structure with 3-6 carbon atoms, and may contain an O atom or a second N atom. A wide variety of R_f ¹ groups are suitable. In some embodiments, R_f ¹ is a linear fluoroalkyl group containing 1-5 carbon atoms. In other embodiments, R_f ¹ is a linear fluoroalkyl group containing 1-5 carbon atoms and containing 1 H atom. A wide variety of R_f ² and R_f ³ groups and combinations of groups are suitable. In some embodiments, each R_f ² and R_f ³ is independently a perfluorinated alkyl group containing 1-3 carbon atoms. In some embodiments, both R_f ² and R_f ³ are the same perfluorinated alkyl group containing 1-3 carbon atoms. In other embodiments, R_f ² and R_f ³ together form a perfluorinated ring structure. In some embodiments R_f ² and R_f ³ together form a perfluorinated ring structure with 3-6 carbon atoms. In other embodiments, where R_f ² and R_f ³ together form a perfluorinated ring structure with 3-6 carbon atoms, where the ring structure contains an O atom or a second N atom. If the ring structure contains a second N atom the N atom is a tertiary amine group bonded to a perfluorinated alkyl group containing 1-3 carbon atoms. In some embodiments, the fluorine content in the hydrofluoroolefin compounds of the present disclosure may be sufficient to make the compounds non-flammable according to ASTM D-3278-96 e-1 test method (“Flash Point of Liquids by Small Scale Closed Cup Apparatus”). In various embodiments, representative examples of the compounds of general Formula I include the following:

. In some embodiments, the hydrofluoroolefin amine compounds of the present disclosure may be hydrophobic, relatively chemically unreactive, and thermally stable. The hydrofluoroolefin compounds may have a low environmental impact. In this regard, the hydrofluoroolefin compounds of the present disclosure may have a global warming potential (GWP) of less than 500, 400, 300, 250, 200, 275, 150, 100, 80, or even 50. As used herein, GWP is a relative measure of the global warming potential of a compound based on the structure of the compound. The GWP of a compound, as defined by the Intergovernmental Panel on Climate Change (IPCC) in 1990 and updated in 2007, is calculated as the warming due to the release of 1 kilogram of a compound relative to the warming due to the release of 1 kilogram of CO₂ over a specified integration time horizon (ITH).

In this equation a_i is the radiative forcing per unit mass increase of a compound in the atmosphere (the change in the flux of radiation through the atmosphere due to the IR absorbance of that compound), C is the atmospheric concentration of a compound, ^ is the atmospheric lifetime of a compound, t is time, and i is the compound of interest. The commonly accepted ITH is 100 years representing a compromise between short-term effects (20 years) and longer-term effects (500 years or longer). The concentration of an organic compound, i, in the atmosphere is assumed to follow pseudo first order kinetics (i.e., exponential decay). The concentration of CO₂ over that same time interval incorporates a more complex model for the exchange and removal of CO₂ from the atmosphere (the Bern carbon cycle model). Generally, the hydrofluoroolefin amine compositions of the present disclosure have a desirable boiling point range. In some embodiments, the boiling point is no lower than 40, 50, or even 60°C and no higher than 150, 140, 130, 120, 110, 100, 90, or even 80°C. Generally, the hydrofluoroolefin amine compositions of the present disclosure have desirable low temperature properties as demonstrated by determining the pour point. In some embodiments, the desirable low temperature properties are reflected by pour points of less than -40, -50, or even -60°C. Generally, the hydrofluoroolefin amine compositions of the present disclosure have desirable heat transfer properties as demonstrated by determining specific heat values. In some embodiments, the desirable heat transfer properties are reflected by specific heat values of higher than 900, 1,000, 1,050, 1,100, or even 1,150 J/Kg·K (Joules per Kilogram Kelvin). Generally, the hydrofluoroolefin amine compositions of the present disclosure are expected to provide low acute toxicity based on 4-hour acute inhalation studies in rats following U.S. EPA “Health Effects Test Guidelines OPPTS 870.1100 Acute Oral Toxicity” and/or OECD Test No. 436 “Acute Inhalation Toxicity- Acute Toxic Class Method”. In some embodiments, a compound of the present disclosure has a single dose oral median lethal concentration (LC 50) in male and female Sprague-Dawley rats of greater than 1,000, 1,250, 5,000, 10,000, 12,500, 15,000, 18,000, or even 20,000 ppm. The hydrofluouroolefin amine compounds of this disclosure can be prepared following the general reaction schemes shown below in Scheme 1. Scheme 1

In general, the method comprises providing a perfluorinated precursor compound comprising a perfluorinated imine, reacting the perfluorinated precursor with a reaction mixture comprising a fluoride salt in an aprotic organic solvent to form a fluorinated amide salt, quenching the fluorinated amide salt with an electrophile to form a fluorinated compound of general Formula II, and dehydrofluorination with an aqueous solution of a metal hydroxide and a phase transfer catalyst to form a hydrofluoroolefin amine of general Formula I as described above. A wide range of perfluorinated imines are suitable as the perfluorinated precursor compound. The perfluorinated imine has general Formula III: R_f ²-N=CF(-R_f ³) Formula III where Rf² is a perfluorinated alkyl group containing 1-4 carbon atoms and may contain one or more catenated heteroatoms selected from O or N, R_f ³ is a perfluorinated alkyl group containing 1-3 carbon atoms and may contain one or more catenated heteroatoms selected from O or N, or R_f ² and R_f ³ together form a perfluorinated ring structure with 3-6 carbon atoms, and may contain an O atom or a second N atom. Perfluorinated imines of can be prepared by a number of procedures that are well known in the art, as described in references 1-4 below: 1) H.V. Rasika Dias et al. Dalton Trans.2011, 40, 8569 and references cited therein. 2) V. A. Petrov, G. G. Belen’kii, L. S. German Bulletin of the Academy of Sciences of the USSR Division of Chemical Science 198534, 1789. 3) V. A. Petrov et al. Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya 1989, 1, 122. 4) A. F. Gontar et al. Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya 1984, 1874. In some embodiments, the perfluorinated imines include:

Generally, the fluoride salt comprises a metal fluoride salt or a tetraalkylammonium fluoride salt. Suitable fluoride salts include KF (potassium fluoride), RbF (rubidium fluoride), CsF (cesium fluoride), and TBAF (tetrabutylammonium fluoride). The salts are dissolved in one or more aprotic organic solvents. Suitable aprotic organic solvents include glymes (e.g. diglyme, tetraglyme, and DPM (di(propylene glycol) methyl ether)), N,N-dimethylformamide (DMF), N-methylpyrrolidinone (NMP), and N,N- dimethylacetamide (DMA). The combination of the perfluorinated precursor and the fluoride salt forms a fluorinated amide salt. This fluorinated amide salt is quenched with an electrophile. Typically, the electrophile has the general structure: Rf¹-CF₂CH₂-X, where Rf¹ is a linear, branched, or cyclic fluoroalkyl group containing 1-5 carbon atoms and may contain up to 2 H atoms; and X is -OSO₂CF₃, OSO₂CF₂CF₃, or OSO₂CF₂CF₂CF₂CF₃. The reaction of the fluorinated amide salt and electrophile forms a fluorinated compound of general Formula II: (R_f ²-)(R_f ³CF₂-)N-CH₂CF₂-R_f ¹ II where R_f ¹ is a linear, branched, or cyclic fluoroalkyl group containing 1-5 carbon atoms and may contain up to 2 H atoms, R_f ² is a perfluorinated alkyl group containing 1-4 carbon atoms and may contain one or more catenated heteroatoms selected from O or N, R_f ³ is a perfluorinated alkyl group containing 1-3 carbon atoms and may contain one or more catenated heteroatoms selected from O or N, or R_f ² and R_f ³ together form a perfluorinated ring structure with 3-6 carbon atoms, and may contain an O atom or a second N atom. In some embodiments, the fluorinated compound of general Formula II include the following:

. The fluorinated compound of general Formula II undergoes dehydrofluorination with an aqueous solution of a metal hydroxide and a phase transfer catalyst to form a hydrofluoroolefin amine of general Formula I as described above. Examples of suitable metal hydroxides (represented as [M]OH) include KOH (potassium hydroxide), LiOH (lithium hydroxide), and NaOH (sodium hydroxide). Typically, the phase transfer catalyst is a tetraalkylammonium halide phase transfer catalyst such as TBACl, TBAB, ALIQUAT 336, or benzyltriethylammonium chloride. Also disclosed herein are working fluids. The working fluid comprises the hydrofluoroolefin amine compound of general formula I described above. The hydrofluoolefin amine compound is present in the working fluid at an amount of at least 25% by weight based on the total weight of the working fluid. In some embodiments, the above-described hydrofluoroolefin amine compounds is a major component of the working fluid. For example, the working fluids may include at least 50%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 99% by weight of the above-described hydrofluoroolefin amine compounds based on the total weight of the working fluid. In addition to the hydrofluoroolefin amine compounds, the working fluids may include a total of up to 75%, up to 50%, up to 30%, up to 20%, up to 10%, or up to 5% by weight of one or more of the following components: alcohols, ethers, alkanes, alkenes, haloalkenes, perfluorocarbons, perfluorinated tertiary amines, perfluoroethers, cycloalkanes, esters, ketones, oxiranes, aromatics, siloxanes, hydrochlorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, hydrofluoroolefins, hydrochloroolefins, hydrochlorofluoroolefins, hydrofluoroethers, or mixtures thereof, based on the total weight of the working fluid. Such additional components can be chosen to modify or enhance the properties of a composition for a particular use. The working fluids are suitable for a wide variety of uses. In some embodiments, the working fluid comprises a heat transfer fluid, a coating solvent, a foam blowing agent, an electrolyte solvent, an additive for lithium-ion batteries, or a cleaning fluid. In some embodiments, the present disclosure is further directed to an apparatus for heat transfer that includes a device and a mechanism for transferring heat to or from the device. The mechanism for transferring heat may include a heat transfer working fluid that includes a hydrofluoroolefin compounds of the present disclosure. Such devices are described for example in US Patent No.10,717,694. In some embodiments, the hydrofluoroolefin amine compounds of this disclosure can be used in fire extinguishing compositions. The composition may include one or more co-extinguishing agents. In illustrative embodiments, the co-extinguishing agent may include hydrofluorocarbons, hydrochlorofluorocarbons, perfluorocarbons, perfluoropolyethers, hydrofluoroethers, hydrofluoropolyethers, chlorofluorocarbons, bromofluorocarbons, bromochlorofluorocarbons, hydrobromocarbons, iodofluorocarbons, fluorinated ketones, hydrofluorocarbons, hydrochlorofluorocarbons, perfluorocarbons, perfluoropolyethers, hydrofluoroethers, hydrofluoropolyethers, chlorofluorocarbons, bromofluorocarbons, bromochlorofluorocarbons, iodofluorocarbons, hydrobromofluorocarbons, fluorinated ketones, hydrobromocarbons, fluorinated olefins, hydrofluoroolefins, fluorinated sulfones, fluorinated vinylethers, unsaturated fluoro-ethers, bromofluoroolefins, chlorofluorolefins, iodofluoroolefins , fluorinated vinyl amines, fluorinated aminopropenes and mixtures thereof. In some embodiments, the working fluids of the present disclosure can be used in an apparatus for converting thermal energy into mechanical energy in a Rankine cycle. The apparatus may further include a heat source to vaporize the working fluid and form a vaporized working fluid, a turbine through which the vaporized working fluid is passed thereby converting thermal energy into mechanical energy, a condenser to cool the vaporized working fluid after it is passed through the turbine, and a pump to recirculate the working fluid. The desired thermodynamic characteristics of organic Rankine cycle working fluids are well known to those of ordinary skill and are discussed, for example, in U.S. Pat. Appl. Publ. No.2010/0139274 (Zyhowski et al.). In some embodiments, the present disclosure relates to the use of the hydrofluoroolefin amine compounds of the present disclosure as nucleating agents in the production of polymeric foams and in particular in the production of polyurethane foams and phenolic foams. In this regard, in some embodiments, the present disclosure is directed to a foamable composition that includes one or more blowing agents, one or more foamable polymers or precursor compositions thereof, and one or more nucleating agents that include a hydrofluoroolefin amine compound of the present disclosure. In some embodiments, the hydrofluoroolefin amine compounds of the present disclosure can be used as dielectric fluids in electrical devices (e.g., capacitors, switchgear, transformers, or electric cables or buses) that include such dielectric fluids. For purposes of the present application, the term “dielectric fluid” is inclusive of both liquid dielectrics and gaseous dielectrics. The physical state of the fluid, gaseous or liquid, is determined at the operating conditions of temperature and pressure of the electrical device in which it is used. In some embodiments, the dielectric fluids include one or more hydrofluoroolefin amine compounds of the present disclosure and, optionally, one or more second dielectric fluids. Suitable second dielectric fluids include, for example, air, nitrogen, helium, argon, and carbon dioxide, or combinations thereof. The second dielectric fluid may be a non- condensable gas or an inert gas. Generally, the second dielectric fluid may be used in amounts such that vapor pressure is at least 70 kPa at 25^oC, or at the operating temperature of the electrical device. In some embodiments, the hydrofluoroolefin amine compounds of the present disclosure can be used in coating compositions that include a solvent composition and one or more coating materials which are soluble or dispersible in the solvent composition. In various embodiments, the coating materials of the coating compositions may include pigments, lubricants, stabilizers, adhesives, anti-oxidants, dyes, polymers, pharmaceuticals, release agents, inorganic oxides, and the like, and combinations thereof. For example, coating materials may include perfluoropolyether, hydrocarbon, and silicone lubricants; amorphous copolymers of tetrafluoroethylene; polytetrafluoroethylene; or combinations thereof. Further examples of suitable coating materials include titanium dioxide, iron oxides, magnesium oxide, perfluoropolyethers, polysiloxanes, stearic acid, acrylic adhesives, polytetrafluoroethylene, amorphous copolymers of tetrafluoroethylene, or combinations thereof. In some embodiments, the hydrofluoroolefin amine compounds of the present disclosure can be used in cleaning compositions that include one or more co-solvents. In some embodiments, the hydrofluoroolefin amine compounds may be present in an amount greater than 50 weight percent, greater than 60 weight percent, greater than 70 weight percent, or greater than 80 weight percent based upon the total weight of the hydrofluoroolefin amine compounds and the co-solvent(s). In illustrative embodiments, the co-solvent may include alcohols, ethers, alkanes, alkenes, haloalkenes, perfluorocarbons, perfluorinated tertiary amines, perfluoroethers, cycloalkanes, esters, ketones, oxiranes, aromatics, haloaromatics, siloxanes, hydrochlorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, hydrofluoroolefins, hydrochloroolefins, hydrochlorofluoroolefins, hydrofluoroethers, or mixtures thereof. The cleaning compositions can be used in either the gaseous or the liquid state (or both), and any of known or future techniques for “contacting” a substrate can be utilized. For example, a liquid cleaning composition can be sprayed or brushed onto the substrate, a gaseous cleaning composition can be blown across the substrate, or the substrate can be immersed in either a gaseous or a liquid composition. Elevated temperatures, ultrasonic energy, and/or agitation can be used to facilitate the cleaning. Various different solvent cleaning techniques are described by B. N. Ellis in Cleaning and Contamination of Electronics Components and Assemblies, Electrochemical Publications Limited, Ayr, Scotland, pages 182-94 (1986). In some embodiments, the present disclosure further relates to electrolyte compositions that include one or more hydrofluoroolefin amine compounds of the present disclosure. The electrolyte compositions may comprise (a) a solvent composition including one or more of the hydrofluoroolefin amine compounds; and (b) at least one electrolyte salt. The electrolyte compositions of the present disclosure exhibit excellent oxidative stability, and when used in high voltage electrochemical cells (such as rechargeable lithium ion batteries) provide outstanding cycle life and calendar life. For example, when such electrolyte compositions are used in an electrochemical cell with a graphitized carbon electrode, the electrolytes provide stable cycling to a maximum charge voltage of at least 4.5V and up to 6.0V vs. Li/Li⁺. Examples Unless otherwise noted or readily apparent from the context, all parts, percentages, ratios, etc. in the Examples and the rest of the specification are by weight. Materials Used in the Examples

Example 1. Preparation of 2,2,3,3,5,5,6,6-octafluoro-4-(2,3,3,4,4,4-hexafluorobut-1- enyl)morpholine. Step 1: To a 600 mL stainless steel reactor was charged with KF (33.0 g, 569 mmol). The reaction vessel was evacuated, back-filled with N2, and evacuated again before vacuum transferring DMF (230 mL) and CF₃CF₂CF₂CH₂ONf (274 g, 569 mmol) in to the reaction vessel. With stirring, the contents were then heated (30 ⁰C) followed by the slow addition of 2,2,3,3,5,6,6-heptafluoro-1,4-oxazine (120 g, 568 mmol). The resultant reaction mixture was then slowly heated to 55 ⁰C followed by an overnight stir. The resultant mixture was then allowed to cool to room temperature followed by the addition of water (200 mL). The mixture was then transferred to a separatory funnel and removal of the aqueous phase yielded a fluorochemical mixture for which GC-FID analysis indicated formation of 2,2,3,3,5,5,6,6-octafluoro-4-(2,2,3,3,4,4,4-heptafluorobutyl)morpholine (23% uncorrected GC yield). Fractional distillation of the crude fluorochemical mixture produced 2,2,3,3,5,5,6,6-octafluoro-4-(2,2,3,3,4,4,4-heptafluorobutyl)morpholine (124⁰C, 740 mm/Hg) as a colorless liquid (55 g, 23% isolated yield). The purified material was used in the next step. Confirmation of the chemical compound was obtained by conventional proton and fluorine NMR. Step 2: To a 3-neck round-bottom flask equipped with a magnetic stir bar, dry ice condenser, and temperature probe were charged KOH (19.2 g, 291 mmol), TBACl (5.38 g, 19.4 mmol), and water (50 mL). With stirring, KOH and TBACl were dissolved completely before the addition of 2,2,3,3,5,5,6,6-octafluoro-4-(2,2,3,3,4,4,4- heptafluorobutyl)morpholine (40.0 g, 96.8 mmol). The reaction mixture was stirred vigorously at 80⁰C for 3 h. The resultant mixture was then allowed to cool to room temperature and diluted by the addition of water (50 mL). Removal of the aqueous layer yielded 28.9 g of a fluorochemical mixture for which GC-FID analysis indicated formation of 2,2,3,3,5,5,6,6-octafluoro-4-(2,3,3,4,4,4-hexafluorobut-1-enyl)morpholine (59% uncorrected GC yield). Fractional distillation of the crude fluorochemical mixture produced 2,2,3,3,5,5,6,6-octafluoro-4-(2,3,3,4,4,4-hexafluorobut-1-enyl)morpholine (109⁰C, 740 mm/Hg) as a colorless liquid (14.9 g, 39% isolated yield), Example 1. Confirmation of the chemical compound was obtained by conventional proton and fluorine NMR.

Example 2. Preparation of 2,2,3,3,5,5,6,6-octafluoro-4-(2,3,3,3-tetrafluoroprop-1- enyl)morpholine. Step 1: To a 2-neck round bottom flask equipped with a magnetic stir bar and dry ice condenser was added KF (18.2 g, 313 mmol). The flask was evacuated and backfilled with nitrogen three times before the addition of tetraglyme (200 mL). With stirring, the mixture was cooled with an ice bath and 2,2,3,3,5,6,6-heptafluoro-1,4-oxazine (60.0 g, 284 mmol) was slowly added followed by the dropwise addition of CF₃CF₂CH₂ONf (123 g, 284 mmol). The resultant reaction mixture was allowed to slowly warm to room temperature with stirring overnight. The resultant mixture was then diluted by the addition of water (500 mL). The diluted mixture was transferred to a separatory funnel and further diluted by an additional 500 mL water. Removal of the aqueous phase yielded 108.3 g of a crude fluorochemical mixture for which GC-FID analysis indicated formation of 2,2,3,3,5,5,6,6-octafluoro-4-(2,2,3,3,3-pentafluoropropyl)morpholine (80% uncorrected GC yield). Fractional distillation of the fluorochemical mixture produced 2,2,3,3,5,5,6,6- octafluoro-4-(2,2,3,3,3-pentafluoropropyl)morpholine (104⁰C, 740 mm/Hg) as a colorless liquid (69.2 g, 67% isolated yield). The purified material was used in the next step. Confirmation of the chemical compound was obtained by conventional proton and fluorine NMR. Step 2: To a 3-neck round-bottom flask equipped with a magnetic stir bar, dry ice condenser, and temperature probe were charged KOH (5.45 g, 82.6 mmol), TBACl (0.765 g, 2.75 mmol), and water (10 mL). With stirring, KOH and TBACl were dissolved completely before the addition of 2,2,3,3,5,5,6,6-octafluoro-4-(2,2,3,3,3- pentafluoropropyl)morpholine (10.0 g, 27.5 mmol). The reaction mixture was stirred vigorously at 80⁰C for 3 h. The resultant mixture was then allowed to cool to room temperature and diluted by the addition of water (20 mL). Removal of the aqueous layer yielded a fluorochemical mixture for which fractional distillation produced 2,2,3,3,5,5,6,6- octafluoro-4-(2,3,3,3-tetrafluoroprop-1-enyl)morpholine (98⁰C, 740 mm/Hg) as a colorless liquid (6.2 g, 66% isolated yield), Example 2. Confirmation of the chemical compound was obtained by conventional proton and fluorine NMR.

Example 3. Preparation of 2,2,3,3,5,5,6,6-octafluoro-4-(2,3,3-trifluoroprop-1- enyl)morpholine. Step 1: To a 3-neck round bottom flask equipped with a stir bar and dry ice condenser was added KF (13.8 g, 237 mmol). With stirring, the flask was evacuated and back-filled with N₂ and was then charged with tetraglyme (100 mL) followed by the slow addition of 2,2,3,3,5,6,6-heptafluoro-1,4-oxazine (50.0 g, 237 mmol). The resultant mixture was cooled to 0 ⁰C with stirring followed by the slow addition of CF₂HCF₂CH₂ONf (98.1 g, 237 mmol) over the course of 1 h. The reaction mixture was then allowed to slowly rise to room temperature and stirred overnight. The resultant reaction mixture was then diluted by the slow addition of water (200 mL). The diluted mixture was transferred to a separatory funnel followed by dilution with additional water (200 mL). Removal of the aqueous phase yielded 143 g of a fluorochemical mixture for which GC-FID analysis indicated formation of 2,2,3,3,5,5,6,6-octafluoro-4-(2,2,3,3- tetrafluoropropyl)morpholine (47% uncorrected GC yield). Fractional distillation of the crude fluorochemical mixture produced 2,2,3,3,5,5,6,6-octafluoro-4-(2,2,3,3- tetrafluoropropyl)morpholine (99⁰C, 740 mm/Hg) as a colorless liquid (32.2 g, 39% isolated yield). The purified material was used in the next step. Confirmation of the chemical compound was obtained by conventional proton and fluorine. Step 2: To a 2-neck round bottom flask equipped with a magnetic stir bar, reflux condenser, and temperature probe were charged KOH (11.5 g, 174 mmol), TBPBr (9.8 g, 29.0 mmol), and H₂O (30 mL). With stirring, KOH and TBPBr were dissolved completely before the addition of 2,2,3,3,5,5,6,6-octafluoro-4-(2,2,3,3-tetrafluoropropyl)morpholine (20.0 g, 58.0 mmol). The reaction mixture was stirred vigorously for 4 h at elevated temperature (80⁰C). A distillation head was then attached to one of the flask necks and the reflux condenser was removed. The temperature was increased until fluorochemical distillate was observed which co-distilled with some water. The aqueous layer was removed leaving 15.9 g of a fluorochemical distillate for which GC-FID analysis indicated complete conversion of starting material and formation of 2,2,3,3,5,5,6,6-octafluoro-4- (2,3,3-trifluoroprop-1-enyl)morpholine (37.1% uncorrected GC yield), Example 3. GC- MS analysis confirmed the identity of 2,2,3,3,5,5,6,6-octafluoro-4-(2,3,3-trifluoroprop-1- enyl)morpholine.

Example 4. Preparation of 2,2,3,3,5,5,6,6-octafluoro-4-(2,3,3,4,4,5,5-heptafluoropent-1- enyl)morpholine. Step 1: To a 3-neck round bottom flask equipped with a stir bar and dry ice condenser was added KF (22.7 g, 391 mmol). With stirring, the flask was evacuated and back-filled with N₂ and was then charged with tetraglyme (200 mL) followed by the slow addition of 2,2,3,3,5,6,6-heptafluoro-1,4-oxazine (75.0 g, 355 mmol). The resultant mixture was cooled to 0⁰C with stirring followed by the slow addition of CF₂HCF₂CF₂CF₂CH₂ONf (183 g, 355 mmol) over the course of 1 h. The reaction mixture was then allowed to slowly rise to room temperature and stirred overnight. The resultant reaction mixture was then diluted by the slow addition of water (200 mL). The diluted mixture was transferred to a separatory funnel followed by dilution with additional water (200 mL). Removal of the aqueous phase yielded a fluorochemical mixture for which fractional distillation produced 2,2,3,3,5,5,6,6-octafluoro-4-(2,2,3,3,4,4,5,5- octafluoropentyl)morpholine (153⁰C, 740 mm/Hg) as a colorless liquid (53 g, 34% isolated yield). The purified material was used in the next step. Confirmation of the chemical compound was obtained by conventional proton and fluorine NMR. Step 2: To a 2-neck round bottom flask equipped with a magnetic stir bar, reflux condenser, and temperature probe were charged KOH (4.45 g, 67.4 mmol), TBPBr (3.8 g, 11.2 mmol), and H₂O (15 mL). With stirring, KOH and TBPBr were dissolved completely before the addition of 2,2,3,3,5,5,6,6-octafluoro-4-(2,2,3,3,4,4,5,5- octafluoropentyl)morpholine (10.0 g, 22.5 mmol). The reaction mixture was stirred vigorously overnight at elevated temperature (80⁰C) and was then allowed to cool back to room temperature and diluted with H₂O (20 mL). Removal of the aqueous layer yielded a fluorochemical mixture for which GC-FID analysis indicated complete conversion of the starting material. Filtration (0.45 micrometer PVDF syringe filter) of the fluorochemical mixture produced 2,2,3,3,5,5,6,6-octafluoro-4-(2,3,3,4,4,5,5-heptafluoropent-1- enyl)morpholine as a colorless liquid (6.2 g at 91% purity, 59% isolated yield), Example 4. Confirmation of the chemical compound was obtained by conventional proton and fluorine NMR.

Example 5. Preparation of 2,3,3,4,4,4-hexafluoro-N,N-bis(trifluoromethyl)but-1-en-1- amine. Step 1: To a 300 mL stainless steel reaction vessel was charged KF (8.7 g, 150 mmol), DMF (80 mL), and 2,2,3,3,4,4,4-heptafluoro-1,1,2,2,3,3,4,4,4-nonafluorobutane- 1-sulfonate (72.5 g, 150 mmol). The vessel was sealed and evacuated followed by stirring at 30⁰C. 1,1-Difluoro-N-(trifluoromethyl)methanimine (20.1 g, 151 mmol) was slowly added to the stirring mixture over the course of 0.5 h. After complete addition, the reaction temperature was raised to 55⁰C followed by an overnight stir. The reaction mixture was then allowed to cool to room temperature and was then diluted by water (100 mL). After transfer to a separatory funnel, removal of the aqueous phase yielded 68.2 g of a crude fluorochemical mixture for which GC-FID analysis indicated formation of 2,2,3,3,4,4,4- heptafluoro-N,N-bis(trifluoromethyl)butan-1-amine (42% uncorrected GC yield). Fractional distillation of the crude fluorochemical fluid produced 2,2,3,3,4,4,4- heptafluoro-N,N-bis(trifluoromethyl)butan-1-amine (80 ⁰C, 740 mm/Hg) as a colorless liquid (12.6 g, 25% isolated yield). The purified material was used in the next step. Confirmation of the chemical compound was obtained by conventional proton and fluorine NMR. Step 2: To a 2-neck round bottom flask equipped with a magnetic stir bar, reflux condenser, and temperature probe were charged KOH (2.95 g, 44.8 mmol), TBACl (0.83 g, 3.0 mmol), and H₂O (7 mL). With stirring, KOH and TBACl were dissolved completely before the addition of 2,2,3,3,4,4,4-heptafluoro-N,N-bis(trifluoromethyl)butan-1-amine (5.0 g, 15 mmol). The reaction mixture was stirred vigorously overnight at elevated temperature (80⁰C) and was then allowed to cool back to room temperature and diluted with H₂O (10 mL). Removal of the aqueous layer yielded a fluorochemical mixture for which GC-FID analysis indicated complete conversion of the starting material. Filtration (0.45 micrometer PVDF syringe filter) of the fluorochemical mixture produced 2,3,3,4,4,4-hexafluoro-N,N-bis(trifluoromethyl)but-1-en-1-amine as a colorless liquid (2.8 g at 95% purity, 57% isolated yield), Example 5. Confirmation of the chemical compound was obtained by conventional proton and fluorine NMR. Comparative Example 1 (CE-1). Attempted preparation of 4-(2,2-difluorovinyl)- 2,2,3,3,5,5,6,6-octafluoromorpholine. Step 1: To a 3-neck round bottom flask under an N₂ atmosphere and equipped with a temperature probe, magnetic stir bar, and dry ice condenser were charged tetraglyme (75 mL) and CsF (41.2 g, 271 mmol). The resultant stirring mixture was then slowly charged with 2,2,3,3,5,6,6-heptafluoro-1,4-oxazine (55.2 g, 261 mmol) via a PTFE line. To the resultant reaction mixture, CF₃CH₂OTf (53.5 g, 231 mmol) was slowly added. The reaction mixture was stirred for 3 h at the same temperature and was then slowly raised to 50⁰C followed by an overnight stir. After cooling to room temperature, the reaction mixture was diluted by the addition of water (150 mL). The diluted mixture was transferred to a separatory funnel and removal of the aqueous phase yielded 49.7 g of a fluorochemical mixture for which GC-FID analysis revealed formation of 2,2,3,3,5,5,6,6- octafluoro-4-(2,2,2-trifluoroethyl)morpholine (50% uncorrected GC-FID yield). Fractional distillation of the crude fluorochemical mixture produced 2,2,3,3,5,5,6,6-octafluoro-4- (2,2,2-trifluoroethyl)morpholine (91⁰C, 740 mm/Hg) as a colorless liquid (28.8 g, 40% isolated yield). The purified material was used in the next step. Step 2: A 3-neck round bottom flask equipped with a temperature probe, magnetic stir bar, and reflux condenser was charged with 2,2,3,3,5,5,6,6-octafluoro-4-(2,2,2- trifluoroethyl)morpholine (10.1 g, 32.3 mmol), water (7 mL), and KOH (6.3 g, 95 mmol). After the resultant mixture cooled to room temperature, TBACl (0.92 g, 3.3 mmol) was added. With stirring, the reaction mixture was heated (100⁰C) followed by an overnight stir. After cooling to room temperature, GC-FID analysis of the crude reaction mixture indicated no conversion of starting material and no formation of 4-(2,2-difluorovinyl)- 2,2,3,3,5,5,6,6-octafluoromorpholine. Comparative Example 2 (CE-2): Preparation of 1,3,3,3-tetrafluoro-N-(perfluoroethyl)-N- (trifluoromethyl)prop-1-en-1-amine. CE-2 was prepared as described in U.S. Pat. Publ. 2018/0141893, which is incorporated herein by reference in its entirety, Example 1. Comparative Example 3 (CE-3): 3,3,4,4,5,5,6,6,6-nonafluorohex-1-ene. CE-3 was purchase from Synquest Laboratories, Inc., and used as received. Comparative Example 4 (CE-4): 3,3,4,4,5,5-hexafluorocyclopent-1-ene. CE-4 was purchase from Synquest Laboratories, Inc., and used as received. Comparative Example 5 (CE-5): (Z)-1,1,1,4,4,4-hexafluorobut-2-ene. CE-5 was purchase from Synquest Laboratories, Inc., and used as received. Dielectric Constants of Examples 1, and CE-2 through CE-5 The dielectric constant was determined using ASTM D150 with the average value reported at 1 KHz. Dielectric constant values were measured for Example 1, CE-2, CE-3, CE-4, and CE-5. The dielectric constants presented in the Tables 1 and 2, below, were measured using the broadband Dielectric Spectrometer available from Novocontrol Technologies, GmbH, Montabaur, Germany, per ASTM D150-11. This data demonstrates the compatibility of hydrofluoroolefin fluids of the present disclosure for high voltage applications. The results are surprising since similar hydrofluoroolefin structures (e.g., CE-2 – CE-5) show relatively higher dielectric constant values. Table 1.

Table 2.

Claims

What is claimed is: 1. A hydrofluoroolefin amine compound represented by the following general formula (I): (R_f ²-)(R_f ³CF₂-)N-CH=CF-R_f ¹ Formula I wherein R_f ¹ is a linear, branched, or cyclic fluoroalkyl group containing 1-5 carbon atoms and may contain up to 2 H atoms; R_f ² is a perfluorinated alkyl group containing 1-4 carbon atoms and may contain one or more catenated heteroatoms selected from O or N; R_f ³ is a perfluorinated alkyl group containing 1-3 carbon atoms and may contain one or more catenated heteroatoms selected from O or N; or R_f ² and R_f ³ together form a perfluorinated ring structure with 3-6 carbon atoms, and may contain an O atom or a second N atom. 2. The hydrofluoroolefin amine compound of claim 1, wherein R_f ¹ is a linear fluoroalkyl group containing 1-5 carbon atoms. 3. The hydrofluoroolefin amine compound of claim 1, wherein R_f ¹ is a linear fluoroalkyl group containing 1-5 carbon atoms and containing 1 H atom. 4. The hydrofluoroolefin amine compound of claim 1, wherein each R_f ² and R_f ³ is independently a perfluorinated alkyl group containing 1-3 carbon atoms. 5. The hydrofluoroolefin amine compound of claim 1, wherein both R_f ² and R_f ³ are the same perfluorinated alkyl group containing 1-3 carbon atoms. 6. The hydrofluoroolefin amine compound of claim 1, wherein R_f ² and R_f ³ together form a perfluorinated ring structure with 3-6 carbon atoms. 7. The hydrofluoroolefin amine compound of claim 1, wherein R_f ² and R_f ³ together form a perfluorinated ring structure with 3-6 carbon atoms, wherein the ring structure contains an O atom or a second N atom, wherein if the ring structure contains a second N atom the N atom is a tertiary amine group bonded to a perfluorinated alkyl group containing 1-3 carbon atoms. 8. The hydrofluoroolefin amine compound of claim 1, comprising a structure selected from:

9. A working fluid comprising a hydrofluoroolefin amine compound represented by the following general formula (I): (R_f ²-)(R_f ³CF₂-)N-CH=CF-R_f ¹ Formula I wherein R_f ¹ is a linear, branched, or cyclic fluoroalkyl group containing 1-5 carbon atoms and may contain up to 2 H atoms; R_f ² is a perfluorinated alkyl group containing 1-4 carbon atoms and may contain one or more catenated heteroatoms selected from O or N; R_f ³ is a perfluorinated alkyl group containing 1-3 carbon atoms and may contain one or more catenated heteroatoms selected from O or N; or Rf² and Rf³ together form a perfluorinated ring structure with 3-6 carbon atoms, and may contain an O atom or a second N atom; wherein the hydrofluoolefin amine compound is present in the working fluid at an amount of at least 25% by weight based on the total weight of the working fluid. 10. The working fluid of claim 9, wherein the working fluid comprises a heat transfer fluid, a coating solvent, a foam blowing agent, an electrolyte solvent, an additive for lithium-ion batteries, or a cleaning fluid. 11. A method of making a hydrofluoroolefin amine comprising: providing a perfluorinated precursor compound comprising a perfluorinated imine with general structure: R_f ²-N=CF(-R_f ³) wherein Rf² is a perfluorinated alkyl group containing 1-4 carbon atoms and may contain one or more catenated heteroatoms selected from O or N; R_f ³ is a perfluorinated alkyl group containing 1-3 carbon atoms and may contain one or more catenated heteroatoms selected from O or N; or R_f ² and R_f ³ together form a perfluorinated ring structure with 3-6 carbon atoms, and may contain an O atom or a second N atom; reacting the perfluorinated precursor with a reaction mixture comprising a fluoride salt comprising a metal fluoride salt or a tetraalkylammonium fluoride salt, in an aprotic organic solvent, to form a fluorinated amide salt; quenching the fluorinated amide salt with an electrophile Rf¹ -CF₂CH₂-X wherein R_f ¹ is a linear, branched, or cyclic fluoroalkyl group containing 1-5 carbon atoms and may contain up to 2 H atoms; and X is -OSO₂CF₃, OSO₂CF₂CF₃, or OSO₂CF₂CF₂CF₂CF₃; to form a fluorinated compound of general Formula II: (R_f ²-)( R_f ³-CF₂-)N-CH₂CF₂-R_f ¹ II wherein R_f ¹ is a linear, branched, or cyclic fluoroalkyl group containing 1-5 carbon atoms and may contain up to 2 H atoms; R_f ² is a perfluorinated alkyl group containing 1-4 carbon atoms and may contain one or more catenated heteroatoms selected from O or N; R_f ³ is a perfluorinated alkyl group containing 1-3 carbon atoms and may contain one or more catenated heteroatoms selected from O or N; or R_f ² and R_f ³ together form a perfluorinated ring structure with 3-6 carbon atoms, and may contain an O atom or a second N atom; and dehydrofluorination with an aqueous solution of a metal hydroxide and a phase transfer catalyst to form a hydrofluoroolefin amine of general Formula I: (R_f ²-)(R_f ³CF₂-)N-CH=CF-R_f ¹ Formula I wherein R_f ¹, R_f ², and R_f ³ are as defined above. 12. The method of claim 11, wherein the fluorinated compound of general Formula II is selected from:

. 13. The method of claim 11, wherein the perfluorinated imine precursor is selected from: