The thiol-yne reaction (also known as alkyne hydrothiolation) is an organic reaction between a thiol and an alkyne. The reaction product is an alkenyl sulfide. [1] [2] The reaction was first reported in 1949 with thioacetic acid as reagent [3] [4] and rediscovered in 2009. [5] It is used in click chemistry [6] [7] [8] and in polymerization, especially with dendrimers.
Thiol-yne reaction |
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This addition reaction is typically facilitated by a radical initiator or UV irradiation and proceeds through a sulfanyl radical species. With monoaddition a mixture of (E/Z)-alkenes form. The mode of addition is anti-Markovnikov. The radical intermediate can engage in secondary reactions such as cyclisation. [9] [10] With diaddition the 1,2-disulfide or the 1,1- dithioacetal forms. Reported catalysts for radical additions are triethylborane, [11] indium(III) bromide [12] and AIBN. [13] The reaction is also reported to be catalysed by cationic rhodium and iridium complexes, [14] by thorium and uranium complexes, [15] by rhodium complexes, [16] [17] [18] by caesium carbonate [19] and by gold. [20]
Ichinose et al. thiol-yne reaction 1987 [11] |
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Diphenyl disulfide reacts with alkynes to a 1,2-bis(phenylthio)ethylene. [21] Reported alkynes are ynamides. [22] A photoredox thiol-yne reaction has been reported. [23]
In polymer chemistry, systems have been described based on addition polymerization with 1,4-benzenedithiol and 1,4-diethynylbenzene, [24] [25] in the synthesis of other addition polymer systems [26] in the synthesis of dendrimers, [27] [28] [29] [30] in star polymers, [31] [32] [33] [34] in graft polymerization, [35] block copolymers, [36] and in polymer networks. [5] [37] Another reported application is the synthesis of macrocycles via dithiol coupling. [38]
In organic chemistry, allenes are organic compounds in which one carbon atom has double bonds with each of its two adjacent carbon atoms. Allenes are classified as cumulated dienes. The parent compound of this class is propadiene, which is itself also called allene. An group of the structure R2C=C=CR− is called allenyl, where R is H or some alkyl group. Compounds with an allene-type structure but with more than three carbon atoms are members of a larger class of compounds called cumulenes with X=C=Y bonding.
In organometallic chemistry, acetylide refers to chemical compounds with the chemical formulas MC≡CH and MC≡CM, where M is a metal. The term is used loosely and can refer to substituted acetylides having the general structure RC≡CM. Acetylides are reagents in organic synthesis. The calcium acetylide commonly called calcium carbide is a major compound of commerce.
In organic chemistry, the Michael reaction or Michael 1,4 addition is a reaction between a Michael donor and a Michael acceptor to produce a Michael adduct by creating a carbon-carbon bond at the acceptor's β-carbon. It belongs to the larger class of conjugate additions and is widely used for the mild formation of carbon-carbon bonds.
An alkyne trimerisation is a [2+2+2] cycloaddition reaction in which three alkyne units react to form a benzene ring. The reaction requires a metal catalyst. The process is of historic interest as well as being applicable to organic synthesis. Being a cycloaddition reaction, it has high atom economy. Many variations have been developed, including cyclisation of mixtures of alkynes and alkenes as well as alkynes and nitriles.
In chemical synthesis, click chemistry is a class of simple, atom-economy reactions commonly used for joining two molecular entities of choice. Click chemistry is not a single specific reaction, but describes a way of generating products that follow examples in nature, which also generates substances by joining small modular units. In many applications, click reactions join a biomolecule and a reporter molecule. Click chemistry is not limited to biological conditions: the concept of a "click" reaction has been used in chemoproteomic, pharmacological, biomimetic and molecular machinery applications. However, they have been made notably useful in the detection, localization and qualification of biomolecules.
The azide-alkyne Huisgen cycloaddition is a 1,3-dipolar cycloaddition between an azide and a terminal or internal alkyne to give a 1,2,3-triazole. Rolf Huisgen was the first to understand the scope of this organic reaction. American chemist Karl Barry Sharpless has referred to this cycloaddition as "the cream of the crop" of click chemistry and "the premier example of a click reaction".
The Pauson–Khand (PK) reaction is a chemical reaction, described as a [2+2+1] cycloaddition. In it, an alkyne, an alkene and carbon monoxide combine into a α,β-cyclopentenone in the presence of a metal-carbonyl catalyst.
A polyyne is any organic compound with alternating single and triple bonds; that is, a series of consecutive alkynes, (−C≡C−)n with n greater than 1. These compounds are also called polyacetylenes, especially in the natural products and chemical ecology literature, even though this nomenclature more properly refers to acetylene polymers composed of alternating single and double bonds (−CR=CR′−)n with n greater than 1. They are also sometimes referred to as oligoynes, or carbinoids after "carbyne" (−C≡C−)∞, the hypothetical allotrope of carbon that would be the ultimate member of the series. The synthesis of this substance has been claimed several times since the 1960s, but those reports have been disputed. Indeed, the substances identified as short chains of "carbyne" in many early organic synthesis attempts would be called polyynes today.
The Cadiot–Chodkiewicz coupling in organic chemistry is a coupling reaction between a terminal alkyne and a haloalkyne catalyzed by a copper(I) salt such as copper(I) bromide and an amine base. The reaction product is a 1,3-diyne or di-alkyne.
Organonickel chemistry is a branch of organometallic chemistry that deals with organic compounds featuring nickel-carbon bonds. They are used as a catalyst, as a building block in organic chemistry and in chemical vapor deposition. Organonickel compounds are also short-lived intermediates in organic reactions. The first organonickel compound was nickel tetracarbonyl Ni(CO)4, reported in 1890 and quickly applied in the Mond process for nickel purification. Organonickel complexes are prominent in numerous industrial processes including carbonylations, hydrocyanation, and the Shell higher olefin process.
Organocobalt chemistry is the chemistry of organometallic compounds containing a carbon to cobalt chemical bond. Organocobalt compounds are involved in several organic reactions and the important biomolecule vitamin B12 has a cobalt-carbon bond. Many organocobalt compounds exhibit useful catalytic properties, the preeminent example being dicobalt octacarbonyl.
Established in 2005, Polymer Factory concentrates on developing well defined dendrimers and dendron based on 2,2-bis(methylol)propionic acid, where the company has the exclusive right to the production, marketing, and sales of such materials. The company also provides tailor-made hyperbranched polymers. Polymer Factory's research lab is located in Stockholm, Sweden.
Adam S. Veige is a professor of Chemistry at the University of Florida. His research focuses on catalysis and the usage of inorganic compounds, including tungsten and chromium complexes.
In organosulfur chemistry, the thiol-ene reaction is an organic reaction between a thiol and an alkene to form a thioether. This reaction was first reported in 1905, but it gained prominence in the late 1990s and early 2000s for its feasibility and wide range of applications. This reaction is accepted as a click chemistry reaction given the reactions' high yield, stereoselectivity, high rate, and thermodynamic driving force.
In organic chemistry, alkynylation is an addition reaction in which a terminal alkyne is added to a carbonyl group to form an α-alkynyl alcohol.
In organometallic chemistry, the activation of cyclopropanes by transition metals is a research theme with implications for organic synthesis and homogeneous catalysis. Being highly strained, cyclopropanes are prone to oxidative addition to transition metal complexes. The resulting metallacycles are susceptible to a variety of reactions. These reactions are rare examples of C-C bond activation. The rarity of C-C activation processes has been attributed to Steric effects that protect C-C bonds. Furthermore, the directionality of C-C bonds as compared to C-H bonds makes orbital interaction with transition metals less favorable. Thermodynamically, C-C bond activation is more favored than C-H bond activation as the strength of a typical C-C bond is around 90 kcal per mole while the strength of a typical unactivated C-H bond is around 104 kcal per mole.
Vinylcyclopropane [5+2] cycloaddition is a type of cycloaddition between a vinylcyclopropane (VCP) and an olefin or alkyne to form a seven-membered ring.
The Crabbé reaction is an organic reaction that converts a terminal alkyne and aldehyde into an allene in the presence of a soft Lewis acid catalyst and secondary amine. Given continued developments in scope and generality, it is a convenient and increasingly important method for the preparation of allenes, a class of compounds often viewed as exotic and synthetically challenging to access.
Topochemical polymerization is a polymerization method performed by monomers aligned in the crystal state. In this process, the monomers are crystallised and polymerised under external stimuli such as heat, light, or pressure. Compared to traditional polymerisation, the movement of monomers was confined by the crystal lattice in topochemical polymerisation, giving rise to polymers with high crystallinity, tacticity, and purity. Topochemical polymerisation can also be used to synthesise unique polymers such as polydiacetylene that are otherwise hard to prepare.
1,4-Butanedithiol is an organosulfur compound with the formula HSCH2CH2CH2CH2SH. It is a malodorous, colorless liquid that is highly soluble in organic solvents. The compound has found applications in biodegradable polymers.