1608-40-8

Usage

Type of Compound

Aromatic hydrocarbon

Structure

Three phenyl rings connected by carbon-carbon double bonds

Usage in Organic Synthesis

Building block for various materials

Applications

a. Polymers
b. Liquid crystals
c. Electronic and optoelectronic devices (OLEDs, organic photovoltaic cells)

Pharmaceutical Applications

a. Fluorescent probe for detecting DNA
b. Component in the development of new drugs

InChI:InChI=1/C22H18/c1-3-7-19(8-4-1)11-13-21-15-17-22(18-16-21)14-12-20-9-5-2-6-10-20/h1-18H/b13-11-,14-12+

Upstream product

• 1849-27-0 1,4-bis(2-phenylethynyl)benzene 
• 100-42-5 styrene 
• 106-37-6 1.4-dibromobenzene 
• 20767-31-1 benzyl(triphenyl)phosphonium bromide 
• 623-27-8 terephthalaldehyde, 

Downstream Products

• 167999-32-8 ((C5H5)Co)2(β,α,1,2-η:β',α',4,3-η-(p-distyrylbenzene)) 
• 191-24-2 Benzo[ghi]perylene 
• 27759-00-8 C₄₄H₃₂ 

Relevant academic research and scientific papers

Ligand-free (: Z)-selective transfer semihydrogenation of alkynes catalyzed by in situ generated oxidizable copper nanoparticles

Herein, we present (Z)-selective transfer semihydrogenation of alkynes based on in situ generated CuNPs in the presence of hydrogen donors, such as ammonia-borane and a green protic solvent. This environmentally friendly method is characterized by operational simplicity combined with high stereo- and chemoselectivity and functional group compatibility. Auto-oxidation of CuNPs after the completion of a semihydrogenation reaction results in the formation of a water-soluble ammonia complex, so that the catalyst may be reused several times by simple phase-separation with no need for any special regeneration processes. Formed NH4B(OR)4 can be easily transformed back into ammonia-borane or into boric acid. In addition, a one-pot tandem sequence involving a Suzuki reaction followed by semihydrogenation was presented, which allows minimization of chemical waste production.

Chemoselective semihydrogenation of alkynes catalyzed by manganese(i)-PNP pincer complexes

A general manganese catalyzed chemoselective semihydrogenation of alkynes to olefins in the presence of molecular hydrogen is described. The best results are obtained by applying the aliphatic Mn PNP pincer complex Mn-3c which allows the transformation of various substituted internal alkynes to the respective Z-olefins under mild conditions and in high yields. Mechanistic investigations based on experiments and computations indicate the formation of the Z-isomer via an outer-sphere mechanism.

Methanol as the Hydrogen Source in the Selective Transfer Hydrogenation of Alkynes Enabled by a Manganese Pincer Complex

The first base metal-catalyzed transfer hydrogenation of alkynes with methanol is described. An air and moisture stable manganese pincer complex catalyzes the reduction of a variety of different alkynes to the corresponding (Z)-olefins in high yields. The

Copper-catalysed, diboron-mediated: Cis -dideuterated semihydrogenation of alkynes with heavy water

Methods to incorporate deuterium atoms into organic molecules are valuable for the pharmaceutical industry. Here, we found that diboron reagents can efficiently mediate the transfer of two D atoms from heavy water directly onto alkynes through copper-catalysed cis-selective semihydrogenation. Avoiding the use of costly and flammable D2 gas, this safe and practical process can proceed with excellent chemoselectivity and stereoselectivity. Utilizing the present method as the key step, the formal asymmetric total synthesis of d2-deuterium-labeled cis-combretastatin A4 is demonstrated. Mechanistic studies suggest that monoborylation of alkynes is the key step for this semihydrogenation process.

Highly Chemo- and Stereoselective Transfer Semihydrogenation of Alkynes Catalyzed by a Stable, Well-Defined Manganese(II) Complex

Herein we report unprecedented manganese-catalyzed semihydrogenation of internal alkynes to (Z)-alkenes using ammonia borane as a hydrogen donor. The reaction is catalyzed by a pincer complex of the earth-abundant manganese(II) salt in the absence of any

Facile photochemical synthesis of 5,10-disubstituted [5]helicenes by removing molecular orbital degeneracy

Photocyclodehydrogenation is a key reaction to synthesize helicenes; however, because of overannulation, it is not applicable to the synthesis of [5]helicene. Introduction of a cyano group was found to remove the orbital degeneracy of the low-lying unoccupied MOs; consequently, the lowest excitation comprises a single transition involving the C2-antisymmetric MO. Therefore, the problematic overannulation can be effectively suppressed. Moreover, in combination with the Knoevenagel reaction, a one-pot synthesis of 5,10-dicyano[5]helicene with 67% yield was accomplished.

Facile regio- and stereoselective hydrometalation of alkynes with a combination of carboxylic acids and group 10 transition metal complexes: Selective hydrogenation of alkynes with formic acid

A facile, highly stereo- and regioselective hydrometalation of alkynes generating alkenylmetal complex is disclosed for the first time from a reaction of alkyne, carboxylic acid, and a zerovalent group 10 transition metal complex M(PEt3)4 (M = Ni, Pd, Pt). A mechanistic study showed that the hydrometalation does not proceed via the reaction of alkyne with a hydridometal generated by the protonation of a carboxylic acid with Pt(PEt 3)4, but proceeds via a reaction of an alkyne coordinate metal complex with the acid. This finding clarifies the long proposed reaction mechanism that operates via the generation of an alkenylpalladium intermediate and subsequent transformation of this complex in a variety of reactions catalyzed by a combination of Bronsted acid and Pd(0) complex. This finding also leads to the disclosure of an unprecedented reduction of alkynes with formic acid that can selectively produce cis-, trans-alkenes and alkanes by slightly tuning the conditions.

Stereodivergent ruthenium-catalyzed transfer semihydrogenation of diaryl alkynes

[Ru3(CO)12]-catalyzed transfer semihydrogenation of various functionalized diaryl alkynes with N,N-dimethylformamide (DMF) and water as hydrogen source affords cis- and trans-stilbenes. The stereodivergent approach can be switched by the use of acetic (HOAc) or trifluoroacetic (TFA) acid as additives. The catalytic processes can be applied to the synthesis of analogues of natural products such as cis-combretastatin A-4 and trans-resveratrol. Copyright

Highly chemo- and stereoselective palladium-catalyzed transfer semihydrogenation of internal alkynes affording cis -alkenes

DMF (N,N-dimethylformamide)/KOH was found to be an efficient hydrogen source in the Pd(OAc)2-catalyzed transfer semihydrogenation of various functionalized internal alkynes to afford cis-alkenes in good to high yields with excellent chemo- and stereoselectivity. This catalytic process was also applied to the synthesis of analogues of combretastatin A-4.

Palladium-catalyzed arylation of styrene and acrylic acid in water

Palladium-catalyzed arylations of styrene and acrylic acid are shown to occur in the presence of base (Na2CO3 or K2CO3) in pure water using simple palladium compounds as catalyst precursors.Keywords: Palladium; Catalysis; Water; Solvent; Aryl