136295-53-9Relevant articles and documents
VISIBLE-LIGHT MEDIATED ORGANOPHOTOREDOX CATALYTIC DEUTERATION OF AROMATIC AND ALIPHATIC ALDEHYDES
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Paragraph 0071-0072; 0073-0074, (2021/06/22)
Described are methods for preparing a deuterated aldehyde using with a photocatalyst and a hydrogen atom transfer agent in a H2O free solvent comprising D2O and an organic solvent under an inert gas. The methods may be used to convert a wide variety of aldehydes (e.g., aryl, alkyl, or alkenyl aldehydes) to C-1 deuterated aldehydes under mild reaction conditions.
Binuclear Pd(I)-Pd(I) Catalysis Assisted by Iodide Ligands for Selective Hydroformylation of Alkenes and Alkynes
Zhang, Yang,Torker, Sebastian,Sigrist, Michel,Bregovi?, Nikola,Dydio, Pawe?
supporting information, p. 18251 - 18265 (2020/11/02)
Since its discovery in 1938, hydroformylation has been thoroughly investigated and broadly applied in industry (>107 metric ton yearly). However, the ability to precisely control its regioselectivity with well-established Rh- or Co-catalysts has thus far proven elusive, thereby limiting access to many synthetically valuable aldehydes. Pd-catalysts represent an appealing alternative, yet their use remains sparse due to undesired side-processes. Here, we report a highly selective and exceptionally active catalyst system that is driven by a novel activation strategy and features a unique Pd(I)-Pd(I) mechanism, involving an iodide-assisted binuclear step to release the product. This method enables β-selective hydroformylation of a large range of alkenes and alkynes, including sensitive starting materials. Its utility is demonstrated in the synthesis of antiobesity drug Rimonabant and anti-HIV agent PNU-32945. In a broader context, the new mechanistic understanding enables the development of other carbonylation reactions of high importance to chemical industry.
Iron Catalyzed Hydroformylation of Alkenes under Mild Conditions: Evidence of an Fe(II) Catalyzed Process
Pandey, Swechchha,Raj, K. Vipin,Shinde, Dinesh R.,Vanka, Kumar,Kashyap, Varchaswal,Kurungot, Sreekumar,Vinod,Chikkali, Samir H.
supporting information, p. 4430 - 4439 (2018/04/05)
Earth abundant, first row transition metals offer a cheap and sustainable alternative to the rare and precious metals. However, utilization of first row metals in catalysis requires harsh reaction conditions, suffers from limited activity, and fails to tolerate functional groups. Reported here is a highly efficient iron catalyzed hydroformylation of alkenes under mild conditions. This protocol operates at 10-30 bar syngas pressure below 100 °C, utilizes readily available ligands, and applies to an array of olefins. Thus, the iron precursor [HFe(CO)4]-[Ph3PNPPh3]+ (1) in the presence of triphenyl phosphine catalyzes the hydroformylation of 1-hexene (S2), 1-octene (S1), 1-decene (S3), 1-dodecene (S4), 1-octadecene (S5), trimethoxy(vinyl)silane (S6), trimethyl(vinyl)silane (S7), cardanol (S8), 2,3-dihydrofuran (S9), allyl malonic acid (S10), styrene (S11), 4-methylstyrene (S12), 4-iBu-styrene (S13), 4-tBu-styrene (S14), 4-methoxy styrene (S15), 4-acetoxy styrene (S16), 4-bromo styrene (S17), 4-chloro styrene (S18), 4-vinylbenzonitrile (S19), 4-vinylbenzoic acid (S20), and allyl benzene (S21) to corresponding aldehydes in good to excellent yields. Both electron donating and electron withdrawing substituents could be tolerated and excellent conversions were obtained for S11-S20. Remarkably, the addition of 1 mol % acetic acid promotes the reaction to completion within 16-24 h. Detailed mechanistic investigations revealed in situ formation of an iron-dihydride complex [H2Fe(CO)2(PPh3)2] (A) as an active catalytic species. This finding was further supported by cyclic voltammetry investigations and intermediacy of an Fe(0)-Fe(II) species was established. Combined experimental and computational investigations support the existence of an iron-dihydride as the catalyst resting state, which then follows a Fe(II) based catalytic cycle to produce aldehyde.
Chemo- and Regioselective Organo-Photoredox Catalyzed Hydroformylation of Styrenes via a Radical Pathway
Huang, He,Yu, Chenguang,Zhang, Yueteng,Zhang, Yongqiang,Mariano, Patrick S.,Wang, Wei
supporting information, p. 9799 - 9802 (2017/08/02)
An unprecedented, chemo- and regioselective, organo-photoredox catalyzed hydroformylation reaction of aryl olefins with diethoxyacetic acid as the formylation reagent is described. In contrast to traditional transition metal promoted ionic hydroformylation reactions, the new process follows a unique photoredox promoted, free radical pathway. In this process, a formyl radical equivalent, produced from diethoxacetic acid through a dye (4CzIPN) photocatalyzed, sequential oxidation-decarboxylation route, regio- and chemoselectively adds to a styrene substrate. Importantly, under the optimized reaction conditions the benzylic radical formed in this manner is reduced by SET from the anion radical of 4CzIPN to generate a benzylic anion. Finally, protonation produces the hydroformylation product. By using the new protocol, aldehydes can be generated regioselectively in up to 90% yield. A broad array of functional groups is tolerated in the process, which takes place under mild, metal-free conditions.
Photoredox activation for the direct β-arylation of ketones and aldehydes
Pirnot, Michael T.,Rankic, Danica A.,Martin, David B. C.,MacMillan, David W. C.
, p. 1593 - 1596 (2013/05/09)
The direct β-activation of saturated aldehydes and ketones has long been an elusive transformation. We found that photoredox catalysis in combination with organocatalysis can lead to the transient generation of 5π-electron β-enaminyl radicals from ketones and aldehydes that rapidly couple with cyano-substituted aryl rings at the carbonyl β-position. This mode of activation is suitable for a broad range of carbonyl β-functionalization reactions and is amenable to enantioselective catalysis.
Regioselective hydroformylation of vinylarenes in aqueous media by a sol-gel entrapped rhodium catalyst
Nairoukh, Zackaria,Blum, Jochanan
scheme or table, p. 129 - 133 (2012/06/18)
Two methods for selective hydroformylation of vinylarenes in aqueous media are described. One method relies on the application of [Rh(cod)Cl]2 and a tertiary phosphane entrapped within an ionic liquid-confined silica sol-gel support. The second method utilizes the same rhodium compound, encaged within ionic-liquid-free hydrophobicized sol-gel. Both methods are best carried out at 50 °C in aqueous emulsions or microemulsions that consist of the substrate, a surfactant, a co-surfactant and >89% water. The optimal H 2/CO ratio is between 1 and 1.1. Both methods allow the reuse of the heterogenized catalyst for several runs. While the regioselectivity and the yield are hardly affected by the electronic nature of the substrates, they are significantly dependent on the reaction temperature, on the surfactant employed, and on the hydrophobicity of the support of the catalyst. Despite the use of H2 in the reactions, no transformation of the organometallic catalyst into metallic nanoparticles could be detected.
Double arylation of allyl alcohol via a one-pot heck arylation- isomerization-acylation cascade
Colbon, Paul,Ruan, Jiwu,Purdie, Mark,Mulholland, Keith,Xiao, Jianliang
supporting information; experimental part, p. 5456 - 5459 (2011/12/05)
A one-pot, two-step catalytic protocol has been developed. A regioselective Heck coupling between aryl bromides and allyl alcohol leads to the generation of arylated allyl alcohols that in situ isomerize to give aldehydes, which then undergo an acylation reaction with a second aryl bromide. A variety of aryl bromides can be employed in both the initial Heck reaction and the acylation, providing easy access to a wide variety of substituted dihydrochalcones.
Novel Urokinase Inhibitors
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Page/Page column 31, (2009/01/24)
The present invention relates to novel compounds with inhibitory activity towards urokinase plasminogen activator (uPA); to methods for preparation of said uPA inhibitor compounds; to pharmaceutical compositions comprising said uPA inhibitor compounds; to
Nornicotine-organocatalyzed aqueous reduction of α,β-unsaturated aldehydes
Brogan, Andrew P.,Dickerson, Tobin J.,Janda, Kim D.
, p. 4952 - 4954 (2008/09/17)
Nornicotine, a native component of tobacco and minor nicotine metabolite, was found to catalyze the chemoselective reduction of α,β-unsaturated aldehydes under homogeneous aqueous conditions. The Royal Society of Chemistry.
Small, potent, and selective diaryl phosphonate inhibitors for urokinase-type plasminogen activator with in vivo antimetastatic properties
Joossens, Jurgen,Ali, Omar M.,El-Sayed, Ibrahim,Surpateanu, Georgiana,Der Van Veken, Pieter,Lambeir, Anne-Marie,Setyono-Han, Buddy,Foekens, John A.,Schneider, Anneliese,Schmalix, Wolfgang,Haemers, Achtel,Augustyns, Koen
, p. 6638 - 6646 (2008/09/17)
A set of small nonpeptidic diaryl phosphonate inhibitors was prepared. Some of these inhibitors show potent and highly selective irreversible uPA inhibition. The biochemical and modeling data prove that the combination of a benzylguanidine moiety with a d
