766-97-2

Usage

Uses

Used in Organic Synthesis:
4-Ethynyltoluene is used as a key intermediate in the synthesis of various organic compounds, particularly in the formation of bis(bicyclic) products through the cycloaddition of alkynes to the AlN2C2 moiety. This process allows for the creation of complex molecular structures with potential applications in various fields.
Used in Liquid Crystals Industry:
4-Ethynyltoluene serves as an intermediate in the production of liquid crystals, which are essential components in display technologies such as LCD screens. Its unique molecular structure contributes to the development of liquid crystal materials with specific properties, enhancing their performance in electronic devices.

InChI:InChI=1/C9H8/c1-3-9-6-4-8(2)5-7-9/h1,4-7H,2H3

Upstream product

• 42107-37-9 α-chloro-p-methylstyrene 
• 2227-58-9 3-(4-methylphenyl)prop-2-ynoic acid 
• 122-00-9 para-methylacetophenone 
• 33458-08-1 1-(1,2-dibromoethyl)-4-methylbenzene 
• 40886-61-1 (α-ethoxycarbonyl-α-4-methylbenzoylmethylene)triphenylphosphorane 
• 4186-14-5 1-(2-(trimethylsilyl)ethynyl)toluene 
• 67-56-1 methanol 
• 593-53-3 Methyl fluoride 
• 536-74-3 phenylacetylene 
• 65114-80-9 1-(4-Methylphenyl)-1,1-dichlorethan 
• 60512-56-3 1-(2,2-dibromovinyl)-4-methylbenzene 
• 91347-88-5 1-(4-methylphenyl)-1-cyclobutene 
• 79756-91-5 2-methyl-4-(4-methylphenyl)-3-butyn-2-ol 
• 73839-45-9 (E)-trimethyl[2-(4-methylphenyl)ethenyl]silane 

Downstream Products

• 861050-53-5 4-Hydroxy-1-phenyl-2-p-tolyl-naphthalin 
• 102006-96-2 5,5'-di-(4-methylphenyl)-3,3'-bisisoxazole 
• 33491-05-3 1-(2-bromoethynyl)-4-methylbenzene 
• 33675-56-8 1-(iodoethynyl)-4-methylbenzene 
• 22666-07-5 di-p-tolylbutadiyne 
• 31208-53-4 4-p-tolylbut-3-yn-1-ol 
• 52999-14-1 2-(4-p-Tolyl-but-3-ynyloxy)-ethanol 
• 97023-74-0 1-(4-methylphenyl)-hexane-1,5-dione 
• 80221-02-9 4-(p-tolyl)but-3-yn-2-one 
• 93021-70-6 1-phenyl-3-(p-tolyl)prop-2-yn-1-ol 
• 79756-90-4 4-(4-methylphenyl)but-3-yn-2-ol 
• 41193-24-2 N,N-diethyl-3-(p-tolyl)prop-2-yn-1-amine 
• 2749-93-1 1-methyl-4-(1-propyn-1-yl)benzene 
• 57355-73-4 5-(p-tolyl)pent-4-yn-2-ol 

Relevant academic research and scientific papers

Iodonium Cation-Pool Electrolysis for the Three-Component Synthesis of 1,3-Oxazoles

The synthesis of 1,3-oxazoles from symmetrical and unsymmetrical alkynes was realized by an iodonium cation-pool electrolysis of I2 in acetonitrile with a well-defined water content. Mechanistic investigations suggest that the alkyne reacts with the acetonitrile-stabilized I+ ions, followed by a Ritter-type reaction of the solvent to a nitrilium ion, which is then attacked by water. The ring closure to the 1,3-oxazoles released molecular iodine, which was visible by the naked eye. Also, some unsymmetrical internal alkynes were tested and a regioselective formation of a single isomer was determined by two-dimensional NMR experiments.

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.

Synthesis of Phenanthrenes via Palladium-Catalyzed Three-Component Domino Reaction of Aryl Iodides, Internal Alkynes, and o-Bromobenzoic Acids

A new palladium-catalyzed domino alkyne insertion/C-H activation/decarboxylation sequence has been developed, which provides an efficient approach for synthesizing a variety of functionalized phenanthrenes in moderate to good yields. The method shows broad substrate scope and good functional group tolerance by employing readily available materials, including aryl iodides, internal alkynes, and o-bromobenzoic acids, as three-component coupling partners.

Fe-Catalyzed Selective Cyclopropanation of Enynes under Photochemical or Thermal Conditions

The nucleophilic Fe-complex Bu4N[Fe(CO)3(NO)] (TBA[Fe]) catalyzes the cyclopropanation of enynes to substituted propargyl cyclopropanes using diazoesters as carbene surrogates. The catalyst can be activated either thermally in the presence of catalytic amounts of 4-nitroanisole or under photochemical conditions. Cyclopropanation occurs selectively at the enyne moiety; alternative olefinic moieties remain intact.

BF3·OEt2-Promoted Propargyl Alcohol Rearrangement/[1,5]-Hydride Transfer/Cyclization Cascade Affording Tetrahydroquinolines

An efficient BF3·OEt2-mediated propargyl alcohol rearrangement/[1,5]-hydride transfer/cyclization cascade for the synthesis of tetrahydroquinoline derivatives has been described. The substituents adjacent to triple bonds play an important role in the formation of ketones (via [1,3]-hydroxyl shift) or alkenyl fluorides which are products of formal trans-carbofluorination of internal alkynes. This method provides a rapid access to diverse heterocycles in moderate to excellent yields.

Palladium-Catalyzed Cascade Intramolecular Cyclization and Allylation of Enynoates with Allylic Alcohols

A Pd(II)-catalyzed mild and highly regioselective 6-endo cyclization/allylation reaction of enynoates with simple allylic alcohols has been developed. Under mild reaction conditions, the vinyl palladium species generated in situ after cyclization could insert C-C double bond of allylic alcohol through cross-coupling reaction and lead to the formation of allyl pyrone via β-OH elimination. This cascade cross-coupling reaction represents a direct and atom economic methodology for the construction of novel allyl pyrones in moderate to good yields.

Copper-Catalyzed Ring Opening of [1.1.1]Propellane with Alkynes: Synthesis of Exocyclic Allenic Cyclobutanes

Despite the long history and interesting properties of propellanes, these compounds still have tremendous potential to be exploited in synthetic organic chemistry. Herein we disclose an experimentally simple procedure to achieve cyclobutane-containing allenes and alkynes through a copper-catalyzed ring opening of [1.1.1]propellane and subsequent reaction with ethynes.

DBU-Mediated Synthesis of Aryl Acetylenes or 1-Bromoethynylarenes from Aldehydes

Two well known synthetic organic reactions Ramirez olefination and Corey-fuchs reactions are integrated in one-pot sequential manner for the synthesis of arylacetylenes and 1,3-enynes starting directly from commercially available aldehydes. The bicyclic amidine 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) along with additive NaOH not only exclusively afforded the terminal alkynes directly from the aldehydes, but also enhanced the reaction rate. The dynamic nature of DBU also facilitated the isolation of 1-bromoalkynes intermediate products. Selection of additive from NaOH and H2O served as a switch for the synthesis of terminal alkyne and 1-bromoalkynes, respectively. (Figure presented.).

α-Hydroxy-Tetrazoles as Latent Ethynyl Moieties: A Mechanistic Investigation

This article focuses on the dehydration of α-hydroxy-tetrazoles, leading to tetraazafulvenes and then to vinylic carbenes that rearrange into ethynyl moieties through the Fritsch-Buttenberg-Wiechell rearrangement. Each step of this sequence was scrutinized, either by examination of the substrate and/or dehydrating agent scope, or through AM1 calculations, in order to understand the limiting step of this process. This underrated transformation appears to be a viable alternative to existing methods used for transforming aldehydes into alkynes.

Au-Catalyzed Intermolecular [2+2] Cycloadditions between Chloroalkynes and Unactivated Alkenes

The [2+2] cycloaddition is a versatile strategy for the synthesis of strained cyclobutenes of high synthetic value. In this study, two efficient intermolecular [2+2] cycloadditions between two different types of chloroalkynes and unactivated alkene are realized with gold catalysis. Of significance is that the reaction works with challenging monosubstituted unactivated alkenes, which is unprecedented in gold catalysis and scarcely documented in other metal-catalyzed/promoted reactions; moreover, the reaction exhibits excellent regioselectivities, which are much better than those reported in literature. With 1,2-disubstituted unactivated alkenes, the reaction is largely stereospecific. The cyclobutene products can be prepared in nearly gram scale and readily undergo further reactions including various cross-coupling reactions using the C(sp2)-Cl and/or C(sp2)-SPh bond, which in turn substantially broaden the scope of accessible cyclobutenes and enhance the synthetic utility of this bimolecular reaction.