- Synthesis of rac-ɑ-aryl propionaldehydes via branched-selective hydroformylation of terminal arylalkenes using water-soluble Rh-PNP catalyst
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This work detailed the preparation of a class of water-soluble PNP ligands that differed by the nature of the substitute on phenyl ring of ligands. These ligands were incorporated into water-soluble rhodium-PNP complex catalysts that were used to regioselective hydroformylation of a series of terminal arylalkenes, providing efficient access to rac-α-aryl propionaldehydes in good to excellent yield (up to 97%) and branched-regioselectivity (up to 40:1 b/l ratio). Furthermore, gram-scale and diverse synthetic transformation demonstrated synthetic application of this methodology for non-steroidal antiinflammatory drugs.
- Chen, Fen-Er,Gao, Peng,Ke, Miaolin,Liang, Guanfeng,Ru, Tong
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- COMPOUNDS AND METHODS FOR TREATMENT OF HEDGEHOG PATHWAY ASSOCIATED CONDITIONS
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Provided herein is novel compounds of formula (I), (II), (III), (IV), and (V) as described in the specification, and pharmaceutically acceptable salts, solvates, and prodrugs and compositions thereof, and methods of measuring hedgehog pathway activation in tumor cells, examining tumor cell proliferation, differentiation and apoptosis and using the compounds and pharmaceutical compositions disclosed for treatment of diseases and disorders associated with the hedgehog signaling pathway.
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Page/Page column 78; 79
(2020/01/24)
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- Iron Catalyzed Hydroformylation of Alkenes under Mild Conditions: Evidence of an Fe(II) Catalyzed Process
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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.
- Pandey, Swechchha,Raj, K. Vipin,Shinde, Dinesh R.,Vanka, Kumar,Kashyap, Varchaswal,Kurungot, Sreekumar,Vinod,Chikkali, Samir H.
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supporting information
p. 4430 - 4439
(2018/04/05)
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- Biocatalytic Parallel Interconnected Dynamic Asymmetric Disproportionation of α-Substituted Aldehydes: Atom-Efficient Access to Enantiopure (S)-Profens and Profenols
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The biocatalytic asymmetric disproportionation of aldehydes catalyzed by horse liver alcohol dehydrogenase (HLADH) was assessed in detail on a series of racemic 2-arylpropanals. Statistical optimization by means of design of experiments (DoE) allowed the identification of critical interdependencies between several reaction parameters and revealed a specific experimental window for reaching an ′optimal compromise′ in the reaction outcome. The biocatalytic system could be applied to a variety of 2-arylpropanals and granted access in a redox-neutral manner to enantioenriched (S)-profens and profenols following a parallel interconnected dynamic asymmetric transformation (PIDAT). The reaction can be performed in aqueous buffer at ambient conditions, does not rely on a sacrificial co-substrate, and requires only catalytic amounts of cofactor and a single enzyme. The high atom-efficiency was exemplified by the conversion of 75 mM of rac-2-phenylpropanal with 0.03 mol% of HLADH in the presence of ～0.013 eq. of oxidized nicotinamide adenine dinucleotide (NAD+), yielding 28.1 mM of (S)-2-phenylpropanol in 96% ee and 26.5 mM of (S)-2-phenylpropionic acid in 89% ee, in 73% overall conversion. Isolated yield of 62% was obtained on 100 mg-scale, with intact enantiopurities. (Figure presented.).
- Tassano, Erika,Faber, Kurt,Hall, Mélanie
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supporting information
p. 2742 - 2751
(2018/07/29)
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- METHODS OF ACYLATION WITH AN IONIC LIQUID CATALYZING MEDIUM
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Described herein are methods of acylating an aryl substrate comprising combining a substituted aryl substrate with an acylating agent in the presence of a catalyzing medium, thereby acylating the substituted aryl substrate in the para position, wherein the catalyzing medium is an ionic liquid comprising at least one cation and at least one metal halide anion.
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- A simple primary amine catalyst for enantioselective α-hydroxylations and α-fluorinations of branched aldehydes
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A new primary amine catalyst for the asymmetric α-hydroxylation and α-fluorination of α-branched aldehydes is described. The products of the title transformations are generated in excellent yields with high enantioselectivities. Both processes can be performed within short reaction times and on gram scale. The similarity in results obtained in both reactions, combined with computational evidence, implies a common basis for stereoinduction and the possibility of a general catalytic mechanism for α-functionalizations. Promising initial results in α-amination and α-chlorination reactions support this hypothesis.
- Witten, Michael R.,Jacobsen, Eric N.
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supporting information
p. 2772 - 2775
(2015/06/16)
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- Exploring the synthetic applicability of a new carboxylic acid reductase from Segniliparus rotundus DSM 44985
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A new carboxylic acid reductase (CAR) gene from Segniliparus rotundus DSM 44985 was overexpressed in Escherichia coli. The recombinant enzyme exhibited high activity toward a variety of aromatic and aliphatic carboxylic acids. Especially, it effectively reduced 4-hydroxybenzoic acid (8a) and 4-nitrobenzoic acid (19a), toward which the known Nocardia CAR exhibited no or little activity. The recombinant E. coli cells co-expressing the Segniliparus CAR and Nocardia PPTase genes catalyzed the reductions of vanillic acid (20a) and 3,4-dihydroxyphenylacetic acid (25a) to give vanillyl alcohol (20c) and 3-hydroxytyrosol (25c) with high yield, respectively. The endogenous aldehyde reductases of E. coli should be responsible for the further reduction of the produced aldehydes. These results demonstrated that Segniliparus CAR was a useful addition to the biocatalyst tool-box for the reduction of carboxylic acids and might find applications in the synthesis of valuable bio-based chemicals from renewable resources.
- Duan, Yitao,Yao, Peiyuan,Chen, Xi,Liu, Xiangtao,Zhang, Rui,Feng, Jinhui,Wu, Qiaqing,Zhu, Dunming
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- Glass wool catalysed regioselective isomerization of styrene oxides
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Glass wool is widely used as an insulating material. Here we report for the first time, the function of glass wool as a mild heterogeneous catalyst under vapor phase conditions - particularly for the rearrangement of styrene oxides including halogen-substituted styrene oxides to the corresponding phenyl acetaldehydes. Using this methodology, 4-isobutyl-α-methyl styrene oxide is smoothly converted to 4-isobutyl α-methyl phenyl acetaldehyde which is the precursor of the API "Ibuprofen" - an important pharmaceutical agent.
- Ramaswamy, Govindarajan K.,Somasundaram, Angalan,Kuppuswamy, Balasubramanian K.,Velayudham, Murugesan
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- Unexpected extension of usage of PPh3/CBr4, a versatile reagent: Isomerization of aromatic allylic alcohols
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The PPh3/CBr4-catalyzed isomerization of 2-aromatic allylic alcohols into the corresponding saturated aldehydes or ketones has been achieved at room temperature in good to excellent yields under mild and metal-free conditions. This new methodology has been applied successfully to the synthesis of ibuprofen in four steps.
- Gong, Wanchun,Liu, Yun,Xue, Jijun,Xie, Zhixiang,Li, Ying
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p. 1597 - 1599
(2013/02/23)
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- Chemoenzymatic synthesis of (2S)-2-arylpropanols through a dynamic kinetic resolution of 2-arylpropanals with alcohol dehydrogenases
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We applied Horse Liver Alcohol Dehydrogenase (HLADH) to the enantioselective synthesis of six (2S)-2-arylpropanols, useful intermediates in the synthesis of Profens. The influence of substrate structure and reaction conditions on yields and enantioselectivity were investigated. The high yields and high enantioselectivity towards the (S)-enantiomer obtained in the bioreduction of 2-arylpropionic aldehydes, clearly indicate the achievement of a DKR process through a combination of an enzyme-catalyzed kinetic reduction with a chemical base-catalyzed racemization of the unreacted aldehydes. The racemization step is represented by the keto-enol equilibrium of the aldehyde and can be controlled by modulating pH and reaction conditions.
- Galletti, Paola,Emer, Enrico,Gucciardo, Gabriele,Quintavalla, Arianna,Pori, Matteo,Giacomini, Daria
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scheme or table
p. 4117 - 4123
(2010/10/03)
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- Use of a robust dehydrogenase from an archael hyperthermophile in asymmetric catalysis-dynamic reductive kinetic resolution entry into (s)-profens
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Described is an efficient heterologous expression system for Sulfolobus solfataricus ADH-10 (Alcohol Dehydrogenase isozyme 10) and its use in the dynamic reductive kinetic resolution (DYRKR) of 2-arylpropanal (Profen-type) substrates. Importantly, among the 12 aldehydes tested, a general preference for the (S)-antipode was observed, with high ee's for substrates corresponding to the NSAIDs (nonsteroidal anti-inflammatory drugs) naproxen, ibuprofen, flurbiprofen, ketoprofen, and fenoprofen. To our knowledge, this is the first application of a dehydrogenase from this Sulfolobus hyperthermophile to asymmetric synthesis and the first example of a DYRKR with such an enzyme. The requisite aldehydes are generated by Buchwald-Hartwig-type Pd(0)-mediated α-arylation of tert-butyl propionate. This is followed by reduction to the aldehyde in one [lithium diisobutyl tert-butoxyaluminum hydride (LDBBA)] or two steps [LAH/Dess-Martin periodinane]. Treatment of the profenal substrates with SsADH in 5% EtOH/phosphate buffer, pH 9, with catalytic NADH at 80 °C leads to efficient DYRKR, with ee's exceeding 90% for 9 aryl side chains, including those of the aforementioned NSAIDs. An in silico model, consistent with the observed broad side chain tolerance, is presented. Importantly, the SsADH-10 enzyme could be conveniently recycled by exploiting the differential solubility of the organic substrate/product at 80 °C and at rt. Pleasingly, SsADH-10 could be taken through several thermal cycles, without erosion of ee, suggesting this as a generalizable approach to enzyme recycling for hyperthermophilic enzymes. Moreover, the robustness of this hyperthermophilic DH, in terms of both catalytic activity and stereochemical fidelity, speaks for greater examination of such archaeal enzymes in asymmetric synthesis.
- Friest, Jacob A.,Maezato, Yukari,Broussy, Sylvain,Blum, Paul,Berkowitz, David B.
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supporting information; experimental part
p. 5930 - 5931
(2010/07/05)
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- One-step oxidation of 2-arylpropanols to 2-arylpropionic acids: Improving sustainability in the synthesis of profens
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Three oxidation procedures were evaluated for the synthesis of optically pure 2-arylpropionic acids. Efficient, mild, and eco-friendly conditions were obtained with the system comprising TEMPO, NaClO, and NaClO2. Thus a series of profens were obtained in good to excellent yields. Georg Thieme Verlag Stuttgart New York.
- Galletti, Paola,Pori, Matteo,Giacomini, Daria
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experimental part
p. 2644 - 2648
(2010/11/18)
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- Conventional and tandem hydroformylation
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Transition-metal-catalyzed hydroformylation has become an essential tool for the synthesis of aldehydes. In this paper, we highlight several examples of synthetically useful applications of homogeneous and heterogeneous rhodium-catalyzed hydroformylation, as well as several examples of tandem processes involving hydroformylation as a reaction step developed in our laboratory.
- Vasylyev, Maksym,Alper, Howard
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scheme or table
p. 2893 - 2900
(2010/10/21)
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- Highly efficient asymmetric reduction of arylpropionic aldehydes by Horse Liver Alcohol Dehydrogenase through dynamic kinetic resolution
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The enantioselective synthesis of (2S)-2-phenylpropanol and (2S)-2-(4-iso-butylphenyl)propanol ((S)-Ibuprofenol) has been achieved by means of Horse Liver Alcohol Dehydrogenase (HLADH) in buffered aqueous solution or buffered organic solvent mixtures; under the reaction conditions, a dynamic kinetic resolution (DKR) process was realized with good reaction yields and enantiomeric ratios. The Royal Society of Chemistry.
- Giacomini, Daria,Galletti, Paola,Quintavalla, Arianna,Gucciardo, Gabriele,Paradisi, Francesca
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p. 4038 - 4040
(2008/03/27)
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- Synthesis of 2-Arylpropionaldehydes through Hydroformylation
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The rhodium-phospholes and rhodium-phosphanorbornadienes-catalyzed hydroformylation of the readily available vinylarenes 1-3 gives rise to arylpropionaldehydes 4-6 in good yields.
- Neibecker, Denis,Reau, Regis,Lecolier, Serge
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p. 5208 - 5210
(2007/10/02)
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- Synthesis and in solution behaviour of new 2-substituted-4-thiazolidinecarboxylic acid derivatives
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A number of 2-substituted-4-thiazolidinecarboxylic acid derivatives were synthesized by cyclocondensation of L-cysteine or its esters with various aldehydes, resulting from acids provided with antiinflammatory properties. In the cyclocondensation a new chiral center at C-2 position of thiazolidine ring is formed giving rise to a mixture of diastereoisomers which can be partially separated. These diastereoisomers show in solution a fast epimerisation at the same chiral center as evidenced by 1H-nmr studies.
- Chiarino,Ferrario,Pellacini,Sala
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p. 589 - 593
(2007/10/02)
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- Pharmaceutically useful derivatives of thiazolidine-4-carboxylic acid
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Compounds of formula in which R, R1 and Y have the meanings shown in the description, their preparation by condensing an aldehyde or a ketone with cysteine or a derivative thereof and their use in the pharmaceutical field. The compounds of formula I possess antipyretic, anti--inflammatory, mucolytic and analgesic activity together with a low capacity to cause gastric injuries. The compounds of formula I, furthermore, are particularly useful in the treatment of ischemia and reperfusion syndromes.
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- Method for producing 2-(substituted aryl) propionaldehyde
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A 2-(substituted aryl)propionaldehyde of the formula, STR1 (wherein Ar denotes STR2 is produced in high yield by reacting a methyl (substituted aryl) ketone of the formula STR3 with phenyldimethylsulfonium methylsulfate of the formula, STR4 in the presence of alkali metal hydroxide to obtain a reaction mixture containing 2-(substituted aryl)1,2-epoxypropane of the formula, STR5 and thioanisole, and subjecting the reaction mixture to contact with anhydrous MgCl2. The propionaldehyde compound is also produced in high yield by contacting the epoxypropane compound with anhydrous MgCl2 in the presence of a soft nucleophile such as a sulfide, a thiol and a phosphine.
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- A FACILE PREPARATION OF 2-ARYLPROPIONALDEHYDE FROM 1-ARYL-1-PROPENE
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1-Aryl-1-propenes were converted into the corresponding 2-arylpropionaldehydes in high yields by treatment with iodine and silver(I)oxide in aqeous dioxane at room temperature.
- Kikuchi, Haruhiko,Kogure, Katsura,Toyoda, Masashi
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p. 341 - 344
(2007/10/02)
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- Process for the preparation of para-substituted derivatives of alpha-phenylpropionic acid
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Pharmacologically useful alpha (para-alkylphenyl) propionic acids having anti-inflammatory, analgesic and antipyretic activity are prepared from the corresponding 1-haloethyl-para-alkylbenzene by converting same to a diethylacetal via a Grignard reaction, followed by the conversion of said acetal to the corresponding aldehyde by hydrolytic means, converting the said aldehyde to an oxime derivative and hydrolyzing the latter to the desired acid.
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- Process of producing a 2-(4-alkylphenyl)-propionic acid
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A new process of producing a 2-(4-alkylphenyl)-propionic acid known as a valuable anti-inflammatory agent is now provided, which comprises treating an alkyl 3-methyl-3-(4-alkylphenyl)-glycidate with an acid to produce 2-(4-alkylphenyl)-propionaldehyde and 3-methyl-3-(4-alkylphenyl)-pyruvic acid through a new reaction, and then oxidising these intermediate products to the desired 2-(4-alkylphenyl)-propionic acid. This new process is operable in a facile way, gives a high yield of the desired product and is suitable for a commercial practice.
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