6973-60-0Relevant academic research and scientific papers
Catalyst-Controlled Chemodivergent Reactions of 2-Pyrrolyl-α-diazo-β-ketoesters and Enol Ethers: Synthesis of 1,2-Dihydrofuran Acetals and Highly Substituted Indoles
France, Stefan,Guerra Faura, Gabriel,Nguyen, Tena
supporting information, p. 10088 - 10104 (2021/07/31)
A catalyst-controlled, chemodivergent reaction of pyrrolyl-α-diazo-β-ketoesters with enol ethers is reported. While Cu(II) catalysts selectively promoted a [3 + 2] cycloaddition to provide pyrrolyl-substituted 2,3-dihydrofuran (DHF) acetals, dimeric Rh(II) catalysts afforded 6-hydroxyindole-7-carboxylates via an unreported [4 + 2] benzannulation. The choice of enol ether proved to be crucial in determining both regioselectivity and yield of the respective products (up to 91% yield for Cu(II) and 82% for Rh(II) catalysis). Furthermore, the DHF acetals were shown to serve as precursors to 7-hydroxyindole-6-carboxylates (isomeric to the indoles formed from Rh) and highly substituted furans in the presence of Lewis acids. Thus, from a common pyrrolyl-α-diazo-β-ketoester, up to three unique heterocyclic scaffolds can be achieved based on catalyst selection.
Redirection of the Transcription Factor SP1 to AT Rich Binding Sites by a Synthetic Adaptor Molecule
Bolz, Mathias,Scheffer, Ute,Kalden, Elisabeth,G?bel, Michael W.
, (2021/08/25)
The ubiquitous transcription factor SP1 binds to a GC rich consensus sequence. Here we describe an adaptor molecule that mediates binding of SP1 to a non-cognate DNA site rich in AT. The adaptor is comprised of a Dervan-type hairpin polyamide with high affinity to an AT rich hexamer duplex. It also carries a 27mer DNA that contains the SP1 consensus sequence. The synthesis and purification of the polyamide-DNA conjugate is reported. Pulldown experiments and western blot analysis demonstrate adaptor mediated binding of SP1 to the hexamer duplex TTGTTA.
Successive Pd-Catalyzed Decarboxylative Cross-Couplings for the Modular Synthesis of Non-Symmetric Di-Aryl-Substituted Thiophenes
Douglas, Liam Z.,Forgione, Pat,Liu, Jiang Tian,Messina, Cynthia
supporting information, (2020/08/17)
Oligothiophenes are important organic molecules in a number of burgeoning industries as semi-conducting materials due to their extensive π-conjugation and charge transport properties. Typically, non-symmetric, di-aryl-substituted thiophenes are prepared by the successive formation of Grignards, organotin, and/or boronic acid intermediates that can be subsequently employed in cross-coupling reactions. While reliable, these approaches present synthetic difficulties due to the reactivity of organo-metallic/pseudo-metallic species, and produce considerable amounts of waste due to necessary pre-functionalization. We have developed a decarboxylative cross-coupling route as an effective strategy for the modular and less wasteful synthesis of a wide range of non-symmetric, di-arylthiophenes. This method uses a thiophene ester building block for successive decarboxylative palladium-catalyzed couplings that allows for the efficient synthesis and evaluation of the opto-electronic properties of a library of candidate semi-conductors with functional groups that could be challenging to access using previous routes.
Exploration of New Biomass-Derived Solvents: Application to Carboxylation Reactions
Gevorgyan, Ashot,Hopmann, Kathrin H.,Bayer, Annette
, p. 2080 - 2088 (2020/02/20)
A range of hitherto unexplored biomass-derived chemicals have been evaluated as new sustainable solvents for a large variety of CO2-based carboxylation reactions. Known biomass-derived solvents (biosolvents) are also included in the study and the results are compared with commonly used solvents for the reactions. Biosolvents can be efficiently applied in a variety of carboxylation reactions, such as Cu-catalyzed carboxylation of organoboranes and organoboronates, metal-catalyzed hydrocarboxylation, borocarboxylation, and other related reactions. For many of these reactions, the use of biosolvents provides comparable or better yields than the commonly used solvents. The best biosolvents identified are the so far unexplored candidates isosorbide dimethyl ether, acetaldehyde diethyl acetal, rose oxide, and eucalyptol, alongside the known biosolvent 2-methyltetrahydrofuran. This strategy was used for the synthesis of the commercial drugs Fenoprofen and Flurbiprofen.
Microwave-assisted Cannizzaro reaction—Optimisation of reaction conditions
Janczewski, ?ukasz,Walczak, Ma?gorzata,Fr?czyk, Justyna,Kamiński, Zbigniew J.,Kolesińska, Beata
supporting information, p. 3290 - 3300 (2019/11/05)
The microwave-assisted Cannizzaro reaction was studied in order to develop fully reproducible synthetic protocols for transformation of aldehydes to carboxylic acid and alcohols. Optimised were the following process parameters: power, temperature, and time. Aromatic, heteroaromatic and aliphatic aldehydes were used in the studies. It was found that furfural, thiophene-2-carbaldehyde, pyridinecarboxaldehyde and aromatic aldehydes react under mild conditions, while 1-methyl-pyrrole-2-carboxaldehyde derivatives and aliphatic aldehydes require more drastic reaction conditions and a longer exposure time to microwave radiation.
Mechanistic investigations of the asymmetric hydrosilylation of ketimines with trichlorosilane reveals a dual activation model and an organocatalyst with enhanced efficiency
Li,Reeder,Torri,Adams,Jones
, p. 2422 - 2435 (2017/03/20)
Structural probes used to help elucidate mechanistic information of the organocatalyzed asymmetric ketimine hydrosilylation have revealed a new catalyst with unprecedented catalytic activity, maintaining adequate performance at 0.01 mol% loading. A new ‘dual activation’ model has been proposed that relies on the presence of both a Lewis basic and Br?nsted acidic site within the catalyst architecture.
Effective palladium-catalyzed hydroxycarbonylation of aryl halides with substoichiometric carbon monoxide
Korsager, Signe,Taaning, Rolf H.,Skrydstrup, Troels
supporting information, p. 2891 - 2894 (2013/04/10)
A protocol for the Pd-catalyzed hydroxycarbonylation of aryl iodides, bromides, and chlorides has been developed using only 1-5 mol % of CO, corresponding to a pCO as low as 0.1 bar. Potassium formate is the only stoichiometric reagent, acting as a mildly basic nucleophile and a reservoir of CO. The substoichiometric CO could be delivered to the reaction from an acyl-Pd(II) precatalyst, which provides both the CO and an active catalyst, and thereby obviates the need for handling a toxic gas.
Carboxylation of indoles and pyrroles with CO2 in the presence of dialkylaluminum halides
Nemoto, Koji,Onozawa, Satoru,Egusa, Naoki,Morohashi, Naoya,Hattori, Tetsutaro
experimental part, p. 4512 - 4514 (2009/11/30)
The Lewis acid-mediated carboxylation of arenes with CO2 has been successfully applied to 1-substituted indoles and pyrroles by using dialkylaluminum chlorides instead of aluminum trihalides. Thus, the carboxylation of 1-methylindoles, 1-benzyl-, and 1-phenylpyrroles proceeds regioselectively with the aid of an equimolar amount of Me2AlCl under CO2 pressure (3.0 MPa) at room temperature to afford the corresponding indole-3-carboxylic acids and pyrrole-2-carboxylic acids in 61-85% yields, while the same treatment of 1,2,5-trimethylpyrrole affords the 3-carboxylic acid in 52% yield.
Structure-activity relationship and liver microsome stability studies of pyrrole necroptosis inhibitors
Teng, Xin,Keys, Heather,Yuan, Junying,Degterev, Alexei,Cuny, Gregory D.
body text, p. 3219 - 3223 (2009/04/06)
Necroptosis is a regulated caspase-independent cell death pathway resulting in morphology reminiscent of passive non-regulated necrosis. Several diverse structure classes of necroptosis inhibitors have been reported to date, including a series of [1,2,3]thiadiazole benzylamide derivatives. However, initial evaluation of mouse liver microsome stability indicated that this series of compounds was rapidly degraded. A structure-activity relationship (SAR) study of the [1,2,3]thiadiazole benzylamide series revealed that increased mouse liver microsome stability and increased necroptosis inhibitory activity could be accomplished by replacement of the 4-cyclopropyl-[1,2,3]thiadiazole with a 5-cyano-1-methylpyrrole. In addition, the SAR and the cellular activity profiles, utilizing different cell types and necroptosis-inducing stimuli, of representative [1,2,3]thiadiazole and pyrrole derivatives were very similar suggesting that the two compound series inhibit necroptosis in the same manner.
Synthesis of lipid derivatives of pyrrole polyamide and their biological activity
Yamamoto, Masahiko,Zhu, Changjin,Yi, Lui,Rong, Zheng,Miura, Yoshie,Izumi, Minoru,Nakajima, Shuhei,Tanamoto, Ken-Ichi,Shimizu, Sakayu,Baba, Naomichi
, p. 1078 - 1082 (2008/02/04)
Novel fatty acyl and phospholipid derivatives of pyrrole polyamide were synthesized. Their cytotoxicity against a cancer cell line of MT-4 cells and those infected by human immunodeficiency virus (HIV) was examined. Although no anti-HIV activity was found, their cytotoxicitty against the cancer cells was significantly enhanced by introducing a lipophilic group into the pyrrole polyamide.
