Catalyzed syn hydrophosphination of alkynes hirohisa ohmiya department of material chemistry, graduate school of engineering, kyoto university, kyoto. Internal alkynes, just like they sound, are in the center of a molecule. For example, alkynes undergo many of the typical addition reactions of alkenes. Catalyst and solventfree hydrophosphination and multicomponent.
Nucleophilic and freeradical additions of phosphines and. A solvent based switch can be employed wherein the regioselectivity of the reaction is completely altered. Hydrophosphination of unactivated alkenes and alkynes using. Physical properties of alkynes organic chemistry tutorial. Regioselective single and double hydrophosphination and. Lecture outline class odds and ends defining unsaturation in hydrocarbons naming alkenes and alkynes cis and trans isomers reactions of alkenes and alkynes o hydrogenation o halogenation o hydrohalogenation o hydration polymers aromatic compounds properties of aromatic compounds 1. Supplementary information double hydrophosphination of. Diketiminates have been proven to be incredibly effective ligands for catalysis using a range of metal centers. Me 3 sinch 2 ch 2 2 nch 2 ch 2 nsime 2 ch 2zr 1 are greatly enhanced under photolysis, providing viable catalytic hydrophosphination with a broad substrate scope.
Intermolecular hydrophosphination of alkynes and related carbon. A few recent examples reported the use of a metal activation. Intermolecular hydrophosphination of terminal and internal alkynes with diphenylphosphine, catalyzed by palladium and nickel complexes, was accomplished for the first time. Pdf room temperature niii catalyzed hydrophosphination and. Beyond a small number of standout examples, many reports in the literature focus on the use of simple nickel salts. Physical properties of alkynes chemical properties alkynes. Catalyzed hydrophosphination and cyclotrimerization of alkynes. Unsaturated hydrocarbons compare the following structures of ethane, ethene and. Pdf the catalytic activity of nickel complexes in hydrophosphination involving secondary.
Hydrophosphination of alkynes and related reactions. Based on the collective evidence of stoichiometric reactions, nmr monitoring studies, kinetic analysis, and dft calculations, a mechanism involving. Double hydrophosphination of alkynes promoted by rhodium. The catalytic activity of nickel complexes in hydrophosphination involving secondary phosphines is not a commonly studied transformation. Note that if a terminal alkyne is produced, the strong base will deprotonate the alkyne to form an alkynide anion.
This concept article discusses and highlights recent developments that address the ongoing challenges, and identifies areas in metal. Calcium carbide is prepared by heating quicklime with coke. Additions are the most common reactions using alkenes and alkynes addition to. Aibn activation, radical catalysis, functionalised dendrimers, vinylpyridines, polyhedral. Challenges in catalytic hydrophosphination bange 2016. Basepromoted and freeradical initiated addition of secondary phosphine sulfides to alkenes or alkynes are the most practiced methods to. The hydrophosphination of carboncarbon multiple bonds has been generally performed under acid, base or metal catalysis in di. The international union of pure and applied chemistry iupac names for alkynes parallel those of alkenes, except that the family ending is yne rather than ene.
Request pdf photocatalytic hydrophosphination of alkenes and alkynes using diphenylphosphine and triamidoamine. Results on the hydrophosphination of various alkynes 2 are summarized in table 1. Synthesized, isolated, and characterized by xray crystallography and nmr spectroscopic studies, lithium phosphidoaluminate ibu3alpph2lithf3 has been tested as a catalyst for hydrophosphination of alkynes, alkenes, and carbodiimides. Alkynes are hydrocarbons with carboncarbon triple bonds. Both terminal and internal alkynes gave the products 3. A versatile and valuable approach for the synthesis of phosphines volume. Simple alkynes are named much like alkenes, except the ending is changed fromane toyne. Ethyne is prepared on large scale by the reaction of water on calcium carbide. Request pdf hydrophosphination of unactivated alkenes, dienes and alkynes. Selective intermolecular hydrophosphination reactions have been investigated with alkynes. Among hydrocarbons, alkynes have higher boiling point than alkenes and alkanes because of the presence of triple bond in alkynes.
Double hydrophosphination of alkynes promoted by rhodium the. Catalysed hydrofunctionalisation of alkenes and alkynes. Visiblelight and thermal driven double hydrophosphination of terminal alkynes catalyzed by a commercially available iron. Reaction in which the elements of water h and oh are. Herein, alkyl and alkenyl tertiary phosphines are obtained by the addition of diphenylphosphine to alkenes and alkynes, respectively, in the absence of. When acetylene is passed through red hot tube of iron or quartz it trimerises to form benzene. Hydrophosphination of alkenes and alkynes with primary phosphines catalyzed by zirconium complexes bearing aminophenolato ligands. Many regio and stereoselective modifications of related reactions are known. Alkynes are oxidised with alkaline kmno 4 to a variety of products depending upon the structure.
Herein, we report the first example of intramolecular hydrophosphination of a series of nonactivated phosphinoalkenes and. Mar 10, 2008 thus, apart from the quantity of the external base used, the electronic properties of the functional group in the substituted alkynes also play a major role in reaction mechanism of the current hydrophosphination reaction for the chemoselective formation of the 1,1 and 1,2addition products. Herein, we report the first example of intramolecular hydrophosphination of a series of nonactivated phosphinoalkenes. In praxis, the reaction is carried out with moderately strong bases, e. This concept article discusses and highlights recent developments.
Hydrophosphination of unactivated alkenes, dienes and. Unlimited viewing of the article pdf and any associated supplements. The products are potentially useful ligands and organocatalysts. Reactivity that is absent from the literature also speaks to the challenges in catalytic hydrophosphination. Reaction in which halogen is introduced into a molecule 3 hydration. New synthetic reactions catalyzed by cobalt complexes. Hydrophosphination of unactivated alkenes and alkynes. A proton source like h2o must be added to regenerate the terminal alkyne. Higher alkenes and alkynes are named by counting the number of carbons in the longest continuous chain that includes the double or triple bond and appending an ene alkene or yne alkyne suffix to the stem name of the. Alkynes can be internal alkynes or terminal alkynes.
The addition of two phosphines across an alkyne using primary phosphine s is extremely challenging and has only been reported within the last five years 81 cui and coworkers very recently reported the catalytic double phosphination of terminal alkynes 1 2 using diphenyl phosphine 1 87 and a copper nhc system figure 1 28 82 the double. A variety of alkynes, both terminal and internal ones with aryl, alkyl, and carboxyl groups, gave the corresponding alkenylphosphines in a highly regioselective and synselective manner. Whereas diphenylphosphine had been an inaccessible substrate under thermal conditions, complete conversion of alkene substrates to tertiary. View the article pdf and any associated supplements and figures for a period of 48 hours. The use of airsensitive secondary phosphines is avoided in this facile process. Thus, apart from the quantity of the external base used, the electronic properties of the functional group in the substitutedalkynes also play a major role in reaction mechanism of the current hydrophosphination reaction for the chemoselective formation of the 1,1 and 1,2addition products. Oct 11, 2016 the catalytic addition of phosphines to alkenes and alkynes is a very attractive process that offers access to phosphines in a 100% atomeconomic reaction using readily available and inexpensive materials. Phosphine boranes have been found to hydrophosphinate internal, unactivated alkynes at room temperature under basic conditions without the need for catalysts or radical initiators. The loss of a hydrogen atom and a halogen atom from adjacent alkane carbon atoms leads to the formation of an alkene.
Hydrophosphination of alkyne is among the most useful methods to install a phosphine moiety into organic molecule. Hydrocarbon hydrocarbon nomenclature of alkenes and alkynes. Different energy and geometry changes may be required for additions to an alkyne and an alkene so some surprising outcomes may occur with alkynes. This is the best route for entering from aliphatic to aromatic compounds. The acidity of alkynes, nonpolar bonding strength, and linearity is due to the triple bonds in these compounds. Acetylene itself is formed from the reaction of the inorganic compound calcium carbide with water.
Ethylene and acetylene are synonyms in the iupac nomenclature system for ethene and ethyne, respectively. This synthetic study investigates the catalytic ability of a niii. Supported zirconium reactions of alkene or alkyne with diphenylphosphine and. Ambient temperature hydrophosphination of internal, unactivated alkynes and allenyl phosphineoxides with phosphine borane complexes.
Hydrophosphination of alkynes and related reactions catalyzed. The regioselective double hydrophosphination of alkynes mediated by rhodium catalysts is presented. Webster department of chemistry, university of bath, bath ba2 7ay, uk. Alkenes, alkynes, and aromatic compounds hydrocarbons with multiple bonds. Ethyne can also be prepared on industrial scale by pyrolysis of methane at very high temperature of about 1800 k. A versatile and valuable approach for the synthesis of phosphines the last. However, standard catalysts like pdc will not allow hydrogenation to stop before the alkane stage. Methods of preparation of alkynes by dehydrohalogenation. The uniqueness in the alkyne structure is due to the hybridization. Substrate scope, mechanistic considerations and potential future applications are examined in full detail. Hydrophosphination of alkenes and alkynes with primary. In the case of less reactive aliphatic internal alkynes 2e and 2f, relatively drastic conditions were, however, necessary to complete the reaction runs 5 and 6. Synthesis of vinylphosphines by hydrophosphination of alkynes in. The preparations of alkynes are very similar to those of the alkenes.
Synthesis of vinylphosphines by hydrophosphination of. The first three members of alkyne family ethyne, propyne and butyne are colourless gases, the next eight members are liquids and the higher ones are solids. Meanwhile, hydrophosphination of alkenes and alkynes under basecatalyzed or freeradical conditions i. In contrast, the formal analogous addition of ammonia or primary and secondary amines to nonactivated alkenes and alkynes scheme 1. Hydrophosphination of unactivated alkenes, dienes and alkynes. Regio and stereoselective synthesis of alkenylphosphines.
Instead, the reaction takes place through insertion of alkynes to a. Chemical reactions of alkynes chemistry assignment. The physical properties of alkynes are very similar to those of the alkenes. Visible light photocatalysis using a commercially available. Room temperature niii catalyzed hydrophosphination and. Conditions were found which ensure regioselective addition with predominant or exclusive formation of the corresponding. Cobaltcatalyzed syn hydrophosphination of alkynes hirohisa ohmiya, hideki yorimitsu, koichiro oshima department of material chemistry, graduate school of engineering, kyoto university, kyotodaigaku katsura, nishikyoku, kyoto, email.
Hydrophosphination catalysis university of bath research portal. Hydrophosphination of alkynes with diphenylphosphine. In contrast, the formal analogous addition of ammonia or primary and secondary amines to nonactivated alkenes and alkynes scheme 1 does not have comparable significance. Reactions of alkene or alkyne with diphenylphosphine and catalytic. Ambient temperature hydrophosphination of internal. Conversion was quantified by integration of 31p1h nmr spectra. Mechanistic investigation of welldefined cobalt catalyzed. Reaction of an alkyne with a hydrogen halide, leading to formation of a halogenated alkene or alkane. Alkynes are hydrogenated in generally the same way as alkenes. The catalytic addition of phosphines to alkenes and alkynes is a very attractive process that offers access to phosphines in a 100% atomeconomic reaction using readily available and inexpensive materials. The distinctive stereoelectronic properties of the nhc ligand prevent the catalyst deactivation by diphosphine coordination thereby allowing for the closing of a productive catalytic cycle. This method was once an important industrial process for the manufacture of acetylene. Like the alkanes and alkenes, alkynes of four or fewer carbon atoms tend to be gases. Lithiumaluminatecatalyzed hydrophosphination applications.
Hydrocarbon nomenclature of alkenes and alkynes britannica. Photocatalytic hydrophosphination of alkenes and alkynes. Synthesis of vinylphosphines by hydrophosphination of alkynes. Additionally, 1 is a photocatalyst for the dehydrogenation of amine boranes and formation of siloxanes from tertiary silanes. Abstractintermolecular hydrophosphination of terminal and internal alkynes with diphenylphosphine, catalyzed by palladium and nickel complexes, was. Terminal alkynes are at the end, and contain an h atom on at least. Standard procedure for the catalytic hydrophosphination of alkynes.
Alkenes with an electronwithdrawing group also gave the corresponding adducts in good. Some of the important methods of preparation of alkynes are. Pdf room temperature niii catalyzed hydrophosphination. Solubility in nonpolar solvents, such as ether and acetone, is extensive. Transition metal catalyzed hydrophosphination is an economical route for atoms to access a range of functionalized phosphines from alkenes and alkynes. Hydrophosphination of simple alkenes and alkynes is catalyzed by lanthanocene complexes. A novel rhodiumcatalyzed hydrophosphination of alkynes using a silylphosphine as a phosphino group source is described. Nov 22, 2018 selective intermolecular hydrophosphination reactions have been investigated with alkynes. Intermolecular hydrophosphination of alkynes and dehydrocoupling studies using iron catalysts. Methods of preparation of alkynes by dehydrohalogenation of. The main preparative reactions involve the elimination of groups or ions from molecules, resulting in the formation of. Physical properties of alkynes are very similar to the physical properties of alkenes. Isomerization since highersubstituted alkyl alkynes internal alkynes are more stable than terminal alkynes hyperconjugation, isomerization is favored thermodynamically.
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