Based on the collective evidence of stoichiometric reactions, nmr monitoring studies, kinetic analysis, and dft calculations, a mechanism involving. Hydrocarbon nomenclature of alkenes and alkynes britannica. Supported zirconium reactions of alkene or alkyne with diphenylphosphine and. In contrast, the formal analogous addition of ammonia or primary and secondary amines to nonactivated alkenes and alkynes scheme 1. Standard procedure for the catalytic hydrophosphination of alkynes. Herein, we report the first example of intramolecular hydrophosphination of a series of nonactivated phosphinoalkenes. Methods of preparation of alkynes by dehydrohalogenation. Like the alkanes and alkenes, alkynes of four or fewer carbon atoms tend to be gases. Catalyst and solventfree hydrophosphination and multicomponent. These compounds are slightly soluble in polar solvents and are. The acidity of alkynes, nonpolar bonding strength, and linearity is due to the triple bonds in these compounds. Terminal alkynes are at the end, and contain an h atom on at least.
Herein, we report the first example of intramolecular hydrophosphination of a series of nonactivated phosphinoalkenes and. Hydrophosphination of alkynes with diphenylphosphine. Hydrophosphination of alkenes and alkynes with primary phosphines catalyzed by zirconium complexes bearing aminophenolato ligands. Reactions of alkene or alkyne with diphenylphosphine and catalytic. A novel rhodiumcatalyzed hydrophosphination of alkynes using a silylphosphine as a phosphino group source is described. Supplementary information double hydrophosphination of. Reaction of an alkyne with a hydrogen halide, leading to formation of a halogenated alkene or alkane. The preparations of alkynes are very similar to those of the alkenes. Physical properties of alkynes organic chemistry tutorial.
Calcium carbide is prepared by heating quicklime with coke. Hydrophosphination catalysis university of bath research portal. Hydrophosphination of unactivated alkenes and alkynes. Additionally, 1 is a photocatalyst for the dehydrogenation of amine boranes and formation of siloxanes from tertiary silanes. This method was once an important industrial process for the manufacture of acetylene. The products are potentially useful ligands and organocatalysts. Number the chain from the end closest to the triple bond. Pdf room temperature niii catalyzed hydrophosphination. Pdf room temperature niii catalyzed hydrophosphination and. The main preparative reactions involve the elimination of groups or ions from molecules, resulting in the formation of. This concept article discusses and highlights recent developments.
Request pdf hydrophosphination of unactivated alkenes, dienes and alkynes. Among hydrocarbons, alkynes have higher boiling point than alkenes and alkanes because of the presence of triple bond in alkynes. Webster department of chemistry, university of bath, bath ba2 7ay, uk. Diketiminates have been proven to be incredibly effective ligands for catalysis using a range of metal centers. Alkynes are generally nonpolar molecules with little solubility in polar solvents, such as water. Conversion was quantified by integration of 31p1h nmr spectra. 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. Mechanistic investigation of welldefined cobalt catalyzed.
Results on the hydrophosphination of various alkynes 2 are summarized in table 1. Alkynes are hydrogenated in generally the same way as alkenes. Alkynes can be internal alkynes or terminal alkynes. Alkenes, alkynes, and aromatic compounds hydrocarbons with multiple bonds. Physical properties of alkynes are very similar to the physical properties of alkenes. Catalyzed hydrophosphination and cyclotrimerization of alkynes. Physical properties of alkynes chemical properties alkynes.
Alkynes are oxidised with alkaline kmno 4 to a variety of products depending upon the structure. Photocatalytic hydrophosphination of alkenes and alkynes. 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. This is the best route for entering from aliphatic to aromatic compounds. Since highersubstituted alkyl alkynes internal alkynes are more stable than terminal alkynes hyperconjugation, isomerization is favored thermodynamically. Whereas diphenylphosphine had been an inaccessible substrate under thermal conditions, complete conversion of alkene substrates to tertiary. Basepromoted and freeradical initiated addition of secondary phosphine sulfides to alkenes or alkynes are the most practiced methods to. Alkynes are similar to alkenes in both physical and chemical properties. Alkynes are hydrocarbons with carboncarbon triple bonds. Herein, alkyl and alkenyl tertiary phosphines are obtained by the addition of diphenylphosphine to alkenes and alkynes, respectively, in the absence of a solvent and a catalyst. Note that if a terminal alkyne is produced, the strong base will deprotonate the alkyne to form an alkynide anion. When acetylene is passed through red hot tube of iron or quartz it trimerises to form benzene.
Catalysed hydrofunctionalisation of alkenes and alkynes. 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. The physical properties of alkynes are very similar to those of the alkenes. Unsaturated hydrocarbons compare the following structures of ethane, ethene and.
Request pdf photocatalytic hydrophosphination of alkenes and alkynes using diphenylphosphine and triamidoamine. Chemical reactions of alkynes chemistry assignment. Synthesis of vinylphosphines by hydrophosphination of alkynes in. 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. Ambient temperature hydrophosphination of internal. Hydrophosphination of simple alkenes and alkynes is catalyzed by lanthanocene complexes. Conditions were found which ensure regioselective addition with predominant or exclusive formation of the corresponding. Isomerization since highersubstituted alkyl alkynes internal alkynes are more stable than terminal alkynes hyperconjugation, isomerization is favored thermodynamically. In praxis, the reaction is carried out with moderately strong bases, e. 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. Beyond a small number of standout examples, many reports in the literature focus on the use of simple nickel salts.
A few recent examples reported the use of a metal activation. Instead, the reaction takes place through insertion of alkynes to a. 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. Many regio and stereoselective modifications of related reactions are known. Room temperature niii catalyzed hydrophosphination and. Visiblelight and thermal driven double hydrophosphination of terminal alkynes catalyzed by a commercially available iron. A versatile and valuable approach for the synthesis of phosphines volume. 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.
Hydrophosphination of alkyne is among the most useful methods to install a phosphine moiety into organic molecule. Synthesis of vinylphosphines by hydrophosphination of. Meanwhile, hydrophosphination of alkenes and alkynes under basecatalyzed or freeradical conditions i. View the article pdf and any associated supplements and figures for a period of 48 hours. Hydrophosphination of unactivated alkenes, dienes and alkynes. The hydrophosphination of carboncarbon multiple bonds has been generally performed under acid, base or metal catalysis in di. New synthetic reactions catalyzed by cobalt complexes. A poisoned catalyst will permit the reduction of a triple bond to a double bond by syn addition, but no further. Ambient temperature hydrophosphination of internal, unactivated alkynes and allenyl phosphineoxides with phosphine borane complexes.
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. Alkenes with an electronwithdrawing group also gave the corresponding adducts in good. Substrate scope, mechanistic considerations and potential future applications are examined in full detail. Ethyne is prepared on large scale by the reaction of water on calcium carbide.
Double hydrophosphination of alkynes promoted by rhodium the. The regioselective double hydrophosphination of alkynes mediated by rhodium catalysts is presented. Synthesis of vinylphosphines by hydrophosphination of alkynes. Typical of most electronpoor early metal catalysts for hydrophosphination, this one includes the characteristic ph bond cleavage and pc and ch bond formation. Herein, alkyl and alkenyl tertiary phosphines are obtained by the addition of diphenylphosphine to alkenes and alkynes, respectively, in the absence of.
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. Hydrophosphination of alkenes and alkynes with primary. However, standard catalysts like pdc will not allow hydrogenation to stop before the alkane stage. 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. 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. Acetylene itself is formed from the reaction of the inorganic compound calcium carbide with water.
Pdf the catalytic activity of nickel complexes in hydrophosphination involving secondary. The uniqueness in the alkyne structure is due to the hybridization. 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. Reaction in which the elements of water h and oh are. Challenges in catalytic hydrophosphination bange 2016. Selective intermolecular hydrophosphination reactions have been investigated with alkynes. 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. Ethyne can also be prepared on industrial scale by pyrolysis of methane at very high temperature of about 1800 k. Visible light photocatalysis using a commercially available. Catalyzed syn hydrophosphination of alkynes ohmiya. Nucleophilic and freeradical additions of phosphines and.
Unlimited viewing of the article pdf and any associated supplements. This synthetic study investigates the catalytic ability of a niii. 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. A proton source like h2o must be added to regenerate the terminal alkyne. Regioselective single and double hydrophosphination and. Regio and stereoselective synthesis of alkenylphosphines. Hydrophosphination of unactivated alkenes and alkynes using. The use of airsensitive secondary phosphines is avoided in this facile process. The catalytic activity of nickel complexes in hydrophosphination involving secondary phosphines is not a commonly studied transformation. Intermolecular hydrophosphination of alkynes and dehydrocoupling studies using iron catalysts. Intermolecular hydrophosphination of alkynes and related carbon. A versatile and valuable approach for the synthesis of phosphines the last. Hydrocarbon hydrocarbon nomenclature of alkenes and alkynes.
A solvent based switch can be employed wherein the regioselectivity of the reaction is completely altered. Abstractintermolecular hydrophosphination of terminal and internal alkynes with diphenylphosphine, catalyzed by palladium and nickel complexes, was. Lithiumaluminatecatalyzed hydrophosphination applications. Phosphine boranes have been found to hydrophosphinate internal, unactivated alkynes at room temperature under basic conditions without the need for catalysts or radical initiators. Both terminal and internal alkynes gave the products 3. Simple alkynes are named much like alkenes, except the ending is changed fromane toyne. For example, alkynes undergo many of the typical addition reactions of alkenes. Hydrophosphination of alkynes and related reactions catalyzed. Solubility in nonpolar solvents, such as ether and acetone, is extensive. Solubility of alkynes alkynes like alkanes and alkenes are nonpolar. Hydrophosphination of alkynes and related reactions. Additions are the most common reactions using alkenes and alkynes addition to.
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. The loss of a hydrogen atom and a halogen atom from adjacent alkane carbon atoms leads to the formation of an alkene. Methods of preparation of alkynes by dehydrohalogenation of. Nov 22, 2018 selective intermolecular hydrophosphination reactions have been investigated with alkynes. This concept article discusses and highlights recent developments that address the ongoing challenges, and identifies areas in metal. Different energy and geometry changes may be required for additions to an alkyne and an alkene so some surprising outcomes may occur with alkynes. Intermolecular hydrophosphination of terminal and internal alkynes with diphenylphosphine, catalyzed by palladium and nickel complexes, was accomplished for the first time.
Ethylene and acetylene are synonyms in the iupac nomenclature system for ethene and ethyne, respectively. Some of the important methods of preparation of alkynes are. Hydrophosphination of unactivated alkenes, dienes and. Aibn activation, radical catalysis, functionalised dendrimers, vinylpyridines, polyhedral. 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. Transition metal catalyzed hydrophosphination is an economical route for atoms to access a range of functionalized phosphines from alkenes and alkynes. Double hydrophosphination of alkynes promoted by rhodium. Internal alkynes, just like they sound, are in the center of a molecule. Catalyzed syn hydrophosphination of alkynes hirohisa ohmiya department of material chemistry, graduate school of engineering, kyoto university, kyoto. 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.
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