103140-39-2

Upstream product

• 3032-92-6 4-cyanophenylacetylene 
• 3058-39-7 4-iodobenzonitrile 
• 1066-54-2 trimethylsilylacetylene 
• 1443-80-7 4-cyanophenyl methyl ketone 
• 75230-47-6 N′-(1-(4-cyanophenyl)ethylidene)-4-methylbenzenesulfonohydrazide 
• 115-19-5 2-methyl-but-3-yn-2-ol 
• 201230-82-2 carbon monoxide 
• 107-05-1 3-chloroprop-1-ene 
• 100-44-7 benzyl chloride 

Relevant academic research and scientific papers

Requirement for an oxidant in Pd/Cu co-catalyzed terminal alkyne homocoupling to give symmetrical 1,4-disubstituted 1,3-diynes

(Chemical Equation Presented) Palladium-catalyzed terminal alkyne dimerization, through oxidative homocoupling, is a useful approach to the synthesis of symmetrical 1,4-diynes. Recent investigations have suggested that this reaction might be accomplished in the absence of intentionally added stoichiometric oxidants (to reoxidize Pd(0) to Pd(II)). In this paper, we have fully addressed the question of whether oxygen (or added oxidant) is required to facilitate this process. The presence of a stoichiometric quantity of air (or added oxidant such as I2) is essential for alkyne dimerization. Excess PPh3 inhibits alkyne dimerization to enyne, which only occurs to a significant extent when the reaction is starved of oxidant. Theoretical studies shed more light on the requirement for an oxidant in the homocoupling reaction in order for the process to be theromodynamically favorable. The employment of I2 as the stoichiometric oxidant appears to be the method of choice. The dual role of Cu both in transmetalation of alkynyl units to Pd(II) and in assisting reoxidation of Pd-(0) to Pd(II) is suggested.

Copper Catalysis for Selective Heterocoupling of Terminal Alkynes

A Cu-catalyzed selective aerobic heterocoupling of terminal alkynes is disclosed, which enables the synthesis of a broad range of unsymmetrical 1,3-diynes in good to excellent yields. The results disprove the long-held belief that homocouplings are exclusively favored in the Glaser-Hay reaction.

Formal [4+ 2] reaction between 1,3-diynes and pyrroles: Gold(I)-catalyzed indole synthesis by double hydroarylation

Indole synthesis by a gold(I)-catalyzed intermolecular formal [4+2] reaction between 1,3-diynes and pyrroles has been developed. This reaction involves the hydroarylation of 1,3-diynes with pyrroles followed by an intramolecular hydroarylation to give the 4,7-disubstituted indoles. This reaction can also be applied to the synthesis of carbazoles when indoles are used as the nucleophiles instead of pyrroles.

Copper-catalyzed aerobic oxidative transformation of ketone- Derived N-tosyl hydrazones: An entry to alkynes

A novel strategy involving Cu-catalyzed oxidative transformation of ketone-derived hydrazone moiety to various synthetic valuable internal alkynes and diynes has been developed. This method features inexpensive metal catalyst, green oxidant, good functional group tolerance, high regioselectivity and readily available starting materials. Oxidative deprotonation reactions were carried out to form internal alkynes and symmetrical diynes. Cross-coupling reactions of hydrazones with halides and terminal alkynes were performed to afford functionalized alkynes and unsymmetrical conjugated diynes. A mechanism proceeding through a Cu-carbene intermediate is proposed for the CC triple bond formation.

Single-molecule conductance of functionalized oligoynes: Length dependence and junction evolution

We report a combined experimental and theoretical investigation of the length dependence and anchor group dependence of the electrical conductance of a series of oligoyne molecular wires in single-molecule junctions with gold contacts. Experimentally, we focus on the synthesis and properties of diaryloligoynes with n = 1, 2, and 4 triple bonds and the anchor dihydrobenzo[b]thiophene (BT). For comparison, we also explored the aurophilic anchor group cyano (CN), amino (NH2), thiol (SH), and 4-pyridyl (PY). Scanning tunneling microscopy break junction (STM-BJ) and mechanically controllable break junction (MCBJ) techniques are employed to investigate single-molecule conductance characteristics. The BT moiety is superior as compared to traditional anchoring groups investigated so far. BT-terminated oligoynes display a 100% probability of junction formation and possess conductance values which are the highest of the oligoynes studied and, moreover, are higher than other conjugated molecular wires of similar length. Density functional theory (DFT)-based calculations are reported for oligoynes with n = 1-4 triple bonds. Complete conductance traces and conductance distributions are computed for each family of molecules. The sliding of the anchor groups leads to oscillations in both the electrical conductance and the binding energies of the studied molecular wires. In agreement with experimental results, BT-terminated oligoynes are predicted to have a high electrical conductance. The experimental attenuation constants βH range between 1.7 nm-1 (CN) and 3.2 nm-1 (SH) and show the following trend: β H(CN) H(NH2) H(BT) H(PY) ≈ βH(SH). DFT-based calculations yield lower values, which range between 0.4 nm -1 (CN) and 2.2 nm-1 (PY).

Consecutive one-pot sonogashira-glaser coupling sequence- Direct preparation of symmetrical diynes by sequential Pd/Cu catalysis

Sonogashira coupling and the catalytic Glaser coupling are both catalyzed by the Pd-Cu complex couple and can be concatenated to a consecutive sequentially Pd/Cu-catalyzed process in a one-pot fashion, and air oxygen serves as the only oxidant in the second step. In a pseudo-four-component synthesis, a broad variety of symmetrically substituted 1,4-bis(hetero)aryl-1,3-butadiynes are obtained in good to excellent yields. Interestingly, the presence of iodide ions has been found to be advantageous over other halides to trigger the Pd/Cu-catalyzed Glaser step, and Pd and Cu species, as well as triethylamine as a base, are prerequisite for both couplings, which proceed with higher efficiency if performed in a one-pot sequence. Two catalytic alkyne coupling reactions were combined in a consecutive sequentially Pd/Cu-catalyzed process to furnish a novel pseudo-four-component synthesis of a variety of symmetrically substituted 1,4-bis(hetero)aryl-1,3-butadiynes in goodyields. Pd and Cu species and triethylamine (base) are essential for the couplings, which proceed with higher efficiency if performed in a one-pot sequence. Copyright

Palladium-catalyzed acylation and/or homo-coupling of aryl- and alkyl-acetylenes

Allyl or benzyl halides, through a Pd(0)-catalyzed reaction and under CO pressure, generate acyl-palladium/halides that, in the presence of a base and an aryl- and alkyl-acetylene, undergo nucleophilic acyl substitution giving conjugated acetylenic ketones. Diynes, resulting from alkyne/alkyne homo-coupling, were instead the main products in reactions performed without allyl or benzyl halides. Moreover, dimerization, trimerization, and cyclotrimerization reactions of acetylenes were observed in reaction carried out even without base.

Orientation and substituent effects on the properties of the diacetylene-group connected octaethylporphyrin-dihexylbithiophene derivatives (OEP-DHBTh-X) carrying electron-withdrawing groups

Orientational isomers of the octaethylporphyrin-dihexylbithiophene (OEP-DHBTh) derivatives connected with a diacetylene linkage were synthesized, with various electron-withdrawing substituents X attached at the ends. The effects of DHBTh orientation and X substituent on the properties of OEP-DHBTh-X (X = H, Br, CN, CHO, and NO2) were studied and compared with those of related OEP derivatives.