970-93-4

Upstream product

• 186581-53-3 diazomethane 
• 792-60-9 2,2'-(ethyne-1,2-diyl)dibenzoic acid 
• 610-97-9 o-iodo-methyl-benzoic acid 
• 994-71-8 bis(tributylstannyl)acetylene 
• 33577-99-0 2-ethynyl-benzoic acid methyl ester 
• 142-45-0 Acetylenedicarboxylic acid 
• 33577-96-7 methyl 2-(2-hydroxy-2-methyl-3-butyn-4-yl)benzoate 
• 38399-13-2 2,2'-dibromotolane 
• 172508-28-0 2-prop-1-ynyl-benzoic acid methyl ester 
• 74-86-2 acetylene 
• 610-94-6 2-bromobenzoic acid methyl ester 

Downstream Products

• 107793-07-7 methyl 2-(2-trimethylsilyl-1-ethynyl)benzoate 
• 792-60-9 2,2'-(ethyne-1,2-diyl)dibenzoic acid 
• 60040-81-5 trans-dimethyl 2,2'-(ethene-1,2-diyl)dibenzoate 

Relevant academic research and scientific papers

Iron-Catalyzed Tandem Cyclization of Diarylacetylene to a Strained 1,4-Dihydropentalene Framework for Narrow-Band-Gap Materials

Carbon bridging in a form of a strained 1,4-dihydropentalene framework is an effective strategy for flattening and stabilizing oligophenylenevinylene systems for the development of optoelectronic materials. However, efficient and flexible methods for making such a strained ring system are lacking. We report herein a mild and versatile synthetic access to the 1,4-dihydropentalene framework enabled by iron-catalyzed single-pot tandem cyclization of a diarylacetylene using FeCl2 and PPh3 as catalyst, magnesium/LiCl as a reductant, and 1,2-dichloropropane as a mild oxidant. The new annulation method features two iron-catalyzed transformations used in tandem, a reductive acetylenic carboferration and an oxidation-induced ring contraction of a ferracycle under mild oxidative conditions. The new method provides access not only to a variety of substituted indeno[2,1-a]indenes but also to their thiophene congeners, 4,9-dihydrobenzo[4,5]pentaleno[1,2-b]thiophene (CPTV) and 4,8-dihydropentaleno[1,2-b:4,5-b′]dithiophenes (CTV). With its high highest occupied molecular orbital level and narrow optical gap, CTV serves as a donor unit in a narrow-band-gap non-fullerene acceptor, which shows absorption extending over 1000 nm in the film state, and has found use in a near-infrared photodetector device that exhibited an external quantum efficiency of 72.4% at 940 nm.

Photophysical and theoretical studies of diphenylacetylene derivatives with restricted rotation

Diphenylacetylene derivatives containing electron-donor (amino) and electron-acceptor (ester) groups in 2,2′ or 3,2′ positions in phenyl rings were synthesized to study the effects of intramolecular charge transfer and stiffening of the conformation by in

Catalysts for the alkyne metathesis

Organometallic compounds of the general formula (I), in which M=Mo, W, are claimed.

Direct observation of reduction of Cu(II) to Cu(I) by terminal alkynes

X-ray absorption spectroscopy and in situ electron paramagnetic resonance evidence were provided for the reduction of Cu(II) to Cu(I) species by alkynes in the presence of tetramethylethylenediamine (TMEDA), in which TMEDA plays dual roles as both ligand and base. The structures of the starting Cu(II) species and the obtained Cu(I) species were determined as (TMEDA)CuCl2 and [(TMEDA)CuCl]2 dimer, respectively.

Optimized synthesis, structural investigations, ligand tuning and synthetic evaluation of silyloxy-based alkyne metathesis catalysts

Nitride- and alkylidyne complexes of molybdenum endowed with triarylsilanolate ligands are excellent (pre)catalysts for alkyne-metathesis reactions of all sorts, since they combine high activity with an outstanding tolerance toward polar and/or sensitive functional groups. Structural and reactivity data suggest that this promising application profile results from a favorable match between the characteristics of the high-valent molybdenum center and the electronic and steric features of the chosen Ar3SiO groups. This interplay ensures a well-balanced level of Lewis acidity at the central atom, which is critical for high activity. Moreover, the bulky silanolates, while disfavoring bimolecular decomposition of the operative alkylidyne unit, do not obstruct substrate binding. In addition, Ar3SiO groups have the advantage that they are more stable within the coordination sphere of a high-valent molybdenum center than tert-alkoxides, which commonly served as ancillary ligands in previous generations of alkyne metathesis catalysts. From a practical point of view it is important to note that complexes of the general type [(Ar3SiO)3Mo≡X] (X = N, CR; R = aryl, alkyl, Ar = aryl) can be rendered air-stable with the aid of 1,10-phenanthroline, 2,2'-bipyridine or derivatives thereof. Although the resulting adducts are themselves catalytically inert, treatment with Lewis acidic additives such as ZnCl2 or MnCl2 removes the stabilizing N-donor ligand and gently releases the catalytically active template into the solution. This procedure gives excellent results in alkyne metathesis starting from air-stable and hence user-friendly precursor complexes. The thermal and hydrolytic stability of representative molybdenum alkylidyne and -nitride complexes of this series was investigated and the structure of several decomposition products elucidated. Active yet tamed: Molybdenum benzylidyne complexes endowed with triarylsilanolates as ancillary ligands are superbly active and exquisitely selective alkyne metathesis catalysts, but can be rendered air-stable by reversible complexation with 1,10-phenanthroline or 2,2'-bipyridine (see, e.g., figure). A systematic molecular editing of their basic structural motif furnished a "library" of such catalysts and gave detailed insights into the parameters determining their favorable application profile. Copyright

Practical new silyloxy-based alkyne metathesis catalysts with optimized activity and selectivity profiles

Triphenylsilanolate ligands were found to impart excellent reactivity and outstanding functional group tolerance on molybdenum alkylidyne complexes, which catalyze alkyne metathesis reactions of all sorts. The active species either can be obtained in high yield by adaptation of the established synthesis routes leading to Schrock alkylidynes or can be generated in situ from the molybdenum nitride complex 11, which itself is readily accessible in large quantity from inexpensive sodium molybdate. Complexation of the active silanolate complexes 12 and 24 with 1,10-phenanthroline affords complexes 15 and 25, respectively, which are stable in air for extended periods of time. Although these phenathroline adducts are per se unreactive vis-a-vis alkynes, catalytic activity is conveniently restored upon exposure to MnCl2. Therefore, the practitioner has the choice of different alkyne metathesis (pre)catalysts, which are easy to handle yet broadly applicable and exceedingly tolerant. A host of representative inter- as well as intramolecular alkyne metathesis reactions, including applications to a considerable number of bioactive and, in part, labile natural products, shows the remarkable scope of these new tools. Moreover, it was found that the addition of molecular sieves (5 A ≤ 4 A > 3 A) to the reaction mixture significantly improves the chemical yields while simultaneously increasing the reaction rates. This benefit is ascribed to effective binding of 2-butyne, which is released as the common byproduct in reactions of alkynes bearing a methyl end-cap. Thus, alkyne metatheses can now be performed at ambient temperature with neither the need to apply vacuum to drive the conversion nor recourse to tailor-made substrates. The structures of representative examples of this new generation of alkyne metathesis catalysts in the solid state were determined by X-ray analysis.

Alkyne metathesis: Development of a novel molybdenum-based catalyst system and its application to the total synthesis of epothilone A and C

Sterically hindered molybdenum(III) amido complexes of the general type [Mo{(tBu)(Ar)N}3] (1), upon treatment with CH2Cl2 or other halogen donors, have been converted into highly effective catalysts for all kinds of alkyne metathesis reactions. Although the actual nature of the propagating species formed in situ is still elusive, halogen transfer to the Mo center of 1 plays a decisive role in the activation of such precatalysts. It was possible to isolate and characterize by X-ray crystallography some of the resulting molybdenum halide derivatives such as 15, 16 and 20 which themselves were shown to be catalytically active. Numerous applications illustrate the performance of the catalytic system 1/CH2Cl2 which operates under mild conditions and tolerates an array of polar functional groups. The wide scope allows the method to be implemented into the total synthesis of sensitive and polyfunctional natural products. Most notable among them is a concise entry into the potent anticancer agents epothilone A (86) and C (88). The macrolide core of these targets is forged by ring closing alkyne metathesis (RCAM) of diyne 113, followed by Lindlar hydrogenation of cycloalkyne 114 thus formed. Since this strategy opens a stereoselective entry into (Z)-alkene 115, the approach is inherently more efficient than previous syntheses based on conventional RCM. Wiley-VCH Verlag GmbH, 2001.

Alkyne cross metathesis reactions of extended scope

equation presented A catalyst formed in situ from Mo[N(t-Bu)(Ar)]3 1 (Ar = 3,5-dimethylphenyl) and CH2Cl2 in toluene effects cross metathesis reactions of functionalized alkynes that are beyond reach of more traditional promotors. An application to the synthesis of prostaglandin E2 (PGE2) 19 and the acetylated PGE derivative 18b shows the compatibility of this method with sensitive substrates.

Coupling reactions of ortho-substituted halobenzenes with alkynes. The synthesis of phenylacetylenes and symmetrical or unsymmetrical 1,2-diphenylacetylenes

The Pd- or Pd/Cu-catalyzed coupling reactions of halobenzenes bearing the methyl, hydroxymethyl, acetoxymethyl, methoxycarbonyl, or both methoxy and 4,4-dimethyl-4,5-dihydro-1,3-oxazol-2-yl groups in the ortho-position with gaseous or metallated acetylene, (trialkylsilyl)acetylenes, and arylacetylenes have been systematically studied. Various functionalized aryl- or diarylacetylenes have been synthesized in good to excellent yields. Whereas additional fluoro, nitro, or methoxy group attached to the benzene ring does not interfere in the coupling reactions, the presence of a methoxycarbonyl requires a careful optimization of reaction conditions to achieve moderate yields.