1641-09-4Relevant academic research and scientific papers
Benzodithiophene-thiophene-based photovoltaic polymers with different side-chains
Nguyen, Thanh Luan,Song, Seyeong,Ko, Seo-Jin,Choi, Hyosung,Jeong, Ji-Eun,Kim, Taehyo,Hwang, Sungu,Kim, Jin Young,Woo, Han Young
, p. 854 - 862 (2015)
A series of benzodithiophene-thiophene-based alternating copolymers were synthesized with different side-chains, and their photovoltaic characteristics were examined. The choice of solubilizing side-chains influences significantly the chain conformation, frontier orbital energy levels, intermolecular organization, and the resulting optical, morphological, and photovoltaic properties. The incorporation of an e-withdrawing carbonyl group in the side-chain decreased the highest occupied molecular orbital (HOMO, ca. -5.4 eV) level and improved the chain planarity through intrachain hydrogen bonding. The shortest π-π stacking distance (3.72 ?) was also measured for the alkylcarbonyl-substituted BDTCOT:PC71BM blended film by two dimensional grazing incidence X-ray scattering. With compared to other polymers, the BDTCOT:PC71BM device showed a substantially improved open-circuit voltage and short-circuit current density, leading to a 4.66% power conversion efficiency. The side-chains need to be designed to be multifunctional to induce a deep HOMO level and chain planarity (for interchain ordering) as well as good solution processability.
Development and Molecular Understanding of a Pd-Catalyzed Cyanation of Aryl Boronic Acids Enabled by High-Throughput Experimentation and Data Analysis
De Jesus Silva, Jordan,Bartalucci, Niccolò,Jelier, Benson,Grosslight, Samantha,Gensch, Tobias,Schünemann, Claas,Müller, Bernd,Kamer, Paul C. J.,Copéret, Christophe,Sigman, Matthew S.,Togni, Antonio
, (2021/11/10)
A synthetic method for the palladium-catalyzed cyanation of aryl boronic acids using bench stable and non-toxic N-cyanosuccinimide has been developed. High-throughput experimentation facilitated the screen of 90 different ligands and the resultant statistical data analysis identified that ligand σ-donation, π-acidity and sterics are key drivers that govern yield. Categorization into three ligand groups – monophosphines, bisphosphines and miscellaneous – was performed before the analysis. For the monophosphines, the yield of the reaction increases for strong σ-donating, weak π-accepting ligands, with flexible pendant substituents. For the bisphosphines, the yield predominantly correlates with ligand lability. The applicability of the designed reaction to a wider substrate scope was investigated, showing good functional group tolerance in particular with boronic acids bearing electron-withdrawing substituents. This work outlines the development of a novel reaction, coupled with a fast and efficient workflow to gain understanding of the optimal ligand properties for the design of improved palladium cross-coupling catalysts.
Nickel-Catalyzed Reversible Functional Group Metathesis between Aryl Nitriles and Aryl Thioethers
Delcaillau, Tristan,Boehm, Philip,Morandi, Bill
, p. 3723 - 3728 (2021/04/07)
We describe a new functional group metathesis between aryl nitriles and aryl thioethers. The catalytic system nickel/dcype is essential to achieve this fully reversible transformation in good to excellent yields. Furthermore, the cyanide- and thiol-free reaction shows high functional group tolerance and great efficiency for the late-stage derivatization of commercial molecules. Finally, synthetic applications demonstrate its versatility and utility in multistep synthesis.
Recyclable and Reusable Pd(OAc)2/XPhos–SO3Na/PEG-400/H2O System for Cyanation of Aryl Chlorides with Potassium Ferrocyanide
Cai, Mingzhong,Huang, Bin,Liu, Rong,Xu, Caifeng
, (2021/12/03)
Pd(OAc)2/XPhos–SO3Na in a mixture of poly(ethylene glycol) (PEG-400) and water is shown to be a highly efficient catalyst for the cyanation of aryl chlorides with potassium ferrocyanide. The reaction proceeded smoothly at 100 or 120?oC with K2CO3 or KOAc as base, delivering a variety of aromatic nitriles in good to excellent yields. The isolation of the crude products is facilely performed by extraction with cyclohexane and more importantly, both expensive Pd(OAc)2 and XPhos–SO3Na in PEG-400/H2O system could be easily recycled and reused at least six times without any apparent loss of catalytic efficiency. Graphical Abstract: Palladium-catalyzed cyanation of aryl chlorides with potassium ferrocyanide leading to aryl nitriles by using Pd(OAc)2/XPhos–SO3Na/PEG-400/H2O as a highly efficient and recyclable catalytic system is described.[Figure not available: see fulltext.]
Product selectivity controlled by manganese oxide crystals in catalytic ammoxidation
Hui, Yu,Luo, Qingsong,Qin, Yucai,Song, Lijuan,Wang, Hai,Wang, Liang,Xiao, Feng-Shou
, p. 2164 - 2172 (2021/09/20)
The performances of heterogeneous catalysts can be effectively tuned by changing the catalyst structures. Here we report a controllable nitrile synthesis from alcohol ammoxidation, where the nitrile hydration side reaction could be efficiently prevented by changing the manganese oxide catalysts. α-Mn2O3 based catalysts are highly selective for nitrile synthesis, but MnO2-based catalysts including α, β, γ, and δ phases favour the amide production from tandem ammoxidation and hydration steps. Multiple structural, kinetic, and spectroscopic investigations reveal that water decomposition is hindered on α-Mn2O3, thus to switch off the nitrile hydration. In addition, the selectivity-control feature of manganese oxide catalysts is mainly related to their crystalline nature rather than oxide morphology, although the morphological issue is usually regarded as a crucial factor in many reactions.
Role of Substituents at 3-position of Thienylethynyl Spacer on Electronic Properties in Diruthenium(II) Organometallic Wire-like Complexes
Roy, Sourav Saha,Chowdhury, Sabyasachi Roy,Mishra, Sabyashachi,Patra, Sanjib K.
, p. 3304 - 3313 (2020/09/09)
A series of organometallic complexes [Cl(dppe)2Ru?C≡C-(3-R?C4H2S)-C≡C?Ru(dppe)2Cl] (3-R-C4H2S=3-substituted thienyl moiety; R=?H, ?C2H5, ?C3H7, ?C4H9, ?C6H13, ?OMe, ?CN in 5 a–5 g respectively) have been synthesized by systematic variation of 3-substituents at the thienylethynyl bridging unit. The diruthenum(II) wire-like complexes (5 a–5 g) have been achieved by the reaction of thienylethynyl bridging units, HC≡C-(3-R-C4H2S)-C≡CH (4 a–4 g) with cis-[Ru(dppe)2Cl2]. The wire-like diruthenium(II) complexes undergo two consecutive electrochemical oxidation processes in the potential range of 0.0 - 0.8 V. Interestingly, the wave separation between the two redox waves is greatly influenced by the substituents at the 3-position of the thienylethynyl. Thus, the substitution on 3-position of the thienylethynyl bridging unit plays a pivotal role for tuning the electronic properties. To understand the electronic behavior, density functional theory (DFT) calculations of the selected diruthenium wire-like complexes (5 a–5 e) with different alkyl appendages are performed. The theoretical data demonstrate that incorporation of alkyl groups to the thienylethynyl entity leaves unsymmetrical spin densities, thus affecting the electronic properties. The voltammetric features of the other two Ru(II) alkynyl complexes 5 f and 5 g (with ?OMe and ?CN group respectively) show an apparent dependence on the electronic properties. The electronic properties in the redox conjugate, (5 a+) with Kc of 3.9×106 are further examined by UV-Vis-NIR and FTIR studies, showing optical responses in NIR region along with changes in “?Ru?C≡C?“ vibrational stretching frequency. The origin of the observed electronic transition has been assigned based on time-dependent DFT (TDDFT) calculations.
Atomically Dispersed Ru on Manganese Oxide Catalyst Boosts Oxidative Cyanation
Gates, Bruce C.,Guan, Erjia,Meng, Xiangju,Wang, Chengtao,Wang, Hai,Wang, Liang,Wang, Sai,Xiao, Feng-Shou,Xu, Dongyang,Xu, Hua,Yang, Bo,Zhang, Jian
, p. 6299 - 6308 (2020/07/21)
There is a strong incentive for environmentally benign and sustainable production of organic nitriles to avoid the use of toxic cyanides. Here we report that manganese oxide nanorod-supported single-site Ru catalysts are active, selective, and stable for oxidative cyanation of various alcohols to give the corresponding nitriles with molecular oxygen and ammonia as the reactants. The very low amount of Ru (0.1 wt %) with atomic dispersion boosts the catalytic performance of manganese oxides. Experimental and theoretical results show how the Ru sites enhance the ammonia resistance of the catalyst, bolstering its performance in alcohol dehydrogenation and oxygen activation, the key steps in the oxidative cyanation. This investigation demonstrates the high efficiency of a single-site Ru catalyst for nitrile production.
Visible light-induced direct conversion of aldehydes into nitriles in aqueous medium using Co@g-C3N4 as photocatalyst
Verma, Fooleswar,Shukla, Prashant,Bhardiya, Smita R.,Singh, Manorama,Rai, Ankita,Rai, Vijai K.
, p. 76 - 81 (2018/11/10)
Unprecedented Co@g-C3N4 catalyzed visible light driven efficient conversion of a variety of aldehydes into corresponding nitriles is reported. Operational simplicity, excellent yield of pure products (87–94%), ambient reaction condition, using aqueous methanol as solvent, visible-light photocatalysis are the salient features of envisaged methodology for direct conversion of aldehydes into nitriles. Furthermore, reusability of Co@g-C3N4 was checked up to five runs and it was noticed that there was no substantial change in morphology as well as the catalytic efficiency of catalyst.
2,2-Diazido-1,2-diarylethanones: Synthesis and Reactivity with Primary Amines
Holzschneider, Kristina,H?ring, Andreas P.,Kirsch, Stefan F.
, p. 2824 - 2831 (2019/04/30)
We describe the synthesis and reactivity of a new class of diazidated compounds: the 2,2-diazido-1,2-diarylethanones. The diazides are easily accessible from 1,2-diarylethanones through a mild and simple protocol for the direct oxidative diazidation, using iodine and sodium azide in DMSO at room temperature. In studies towards their reactivity with amine nucleophiles under basic conditions, the diazides are shown to undergo a controlled fragmentation reaction that provides a straightforward access to the corresponding amides. In stark contrast to our previous results on the amine-triggered fragmentation of diazidated compounds, aromatic nitriles are found to be by-products of synthetic value. The net reaction consisting of diazidation and subsequent fragmentation, thus, provides a simple way to convert 1,2-diarylethanones into both aromatic amides and nitriles.
[1+1+3] Annulation of Diazoenals and Vinyl Azides: Direct Synthesis of Functionalized 1-Pyrrolines through Olefination
Kanchupalli, Vinaykumar,Katukojvala, Sreenivas
, p. 5433 - 5437 (2018/04/09)
A dirhodium carboxylate catalyzed [1+1+3] annulation reaction of diazoenals and vinyl azides that gives synthetically important enal-functionalized 1-pyrroline derivatives was developed. The reaction involves a novel rhodium-catalyzed olefination of diazoenals with vinyl azides via electrophilic enal carbenoids, resulting in a new class of enal acrylates. The annulation reaction was used for the direct synthesis of valuable deuterated 1-pyrrolines. Structural diversification of the enal-functionalized 1-pyrrolines resulted in the biologically important pyrrolidine-fused oxaziridine, amino acid derivatives, and a 6-azabicyclo[3.2.1]octane motif present in polycyclic alkaloids.
