18127-01-0Relevant articles and documents
Coordination of bis(azol-1-yl)methane-based bisphosphines towards RuII, RhI, PdII and PtII: synthesis, structural and catalytic studies
Bhat, Sajad A.,Pandey, Madhusudan K.,Mague, Joel T.,Balakrishna, Maravanji S.
, p. 227 - 241 (2017)
The coordination chemistry of bisphosphine ligands assembled on the five-membered heterocyclic platform of bis(azol-1-yl)methane viz.: bis(2-diphenylphosphinoimidazol-1-yl)methane (1), bis(5-diphenylphosphinopyrazol-1-yl)methane (2) and bis(5-diphenylphosphino-1,2,4-triazol-1-yl)methane (3) with RuII, RhI, PdII and PtII is described. The bisphosphines 1-3 react with elemental selenium to give the corresponding bis-selenoyl derivatives 4-6. The reactions of 1-3 with transition metal derivatives produce complexes with different coordination modes. Bisphosphine 1 showed a preference for the κ2-P,P mode of coordination, whereas bisphosphines 2 and 3, besides the κ2-P,P mode also showed a head-to-tail κ2-P,N coordination mode resulting in the formation of binuclear complexes [Rh2(COD)2{(CH2(1,2-C3H2N2PPh2)2)-κ2P,N}][BF4]2 (14), [Rh2(COD)2{(CH2(1,2,4-C2HN3PPh2)2)-κ2P,N}][BF4]2 (15), [Pd2(η3-C3H5)2{(CH2(1,2-C3H2N2PPh2)2)-κ2P,N}][BF4]2 (21) and [Pd2(η3-C3H5)2{(CH2(1,2,4-C2HN3PPh2)2)-κ2P,N}][BF4]2 (22). Several of these complexes have also been structurally characterized. The in situ generated RhI complex of bisphosphine 1 showed moderate to good selectivity in the hydroformylation of various styrene derivatives.
Access to Trisubstituted Fluoroalkenes by Ruthenium-Catalyzed Cross-Metathesis
Nouaille, Augustin,Pannecoucke, Xavier,Poisson, Thomas,Couve-Bonnaire, Samuel
, p. 2140 - 2147 (2021/03/06)
Although the olefin metathesis reaction is a well-known and powerful strategy to get alkenes, this reaction remained highly challenging with fluororalkenes, especially the Cross-Metathesis (CM) process. Our thought was to find an easy accessible, convenient, reactive and post-functionalizable source of fluoroalkene, that we found as the methyl 2-fluoroacrylate. We reported herein the efficient ruthenium-catalyzed CM reaction of various terminal and internal alkenes with methyl 2-fluoroacrylate giving access, for the first time, to trisubstituted fluoroalkenes stereoselectively. Unprecedent TON for CM involving fluoroalkene, up to 175, have been obtained and the reaction proved to be tolerant and effective with a large range of olefin partners giving fair to high yields in metathesis products. (Figure presented.).
Preparation method of 4-tert-butyl phenylpropionaldehyde
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Paragraph 0026-0063, (2021/03/13)
The invention discloses a preparation method of 4-tert-butyl phenylpropionaldehyde, which comprises the following steps: carrying out hydroformylation reaction by using 4-tert-butyl styrene as a raw material to obtain 4-tert-butyl phenylpropionaldehyde, wherein the solvent is dimethylformamide, the catalyst is a rhodium catalyst, the rhodium catalyst is Rh(CO)2C5H7O2, RhHCO(PPh3)3 or Rh(C5H7O2)(CO)(PPh3), the auxiliary agent is a phosphine ligand and an organic alkali compound, the phosphine ligand is diphenyl phosphite, tris (o-methylphenylphosphine) or bis (2,4-dicumylphenyl)pentaerythritoldiphosphite, the organic alkali compound is triethylamine, triphenylphosphine oxide or N,N-diisopropylethylamine. According to the method, the 4-tert-butyl styrene is used as the raw material to prepare 4-tert-butyl phenylpropionaldehyde through one-step hydroformylation reaction, wherein the raw material conversion rate is higher than 98%, and the product yield is higher than 80%. The compound issimple in preparation method, low in production cost and small in environmental harm.
Synthesis of rac-ɑ-aryl propionaldehydes via branched-selective hydroformylation of terminal arylalkenes using water-soluble Rh-PNP catalyst
Chen, Fen-Er,Gao, Peng,Ke, Miaolin,Liang, Guanfeng,Ru, Tong
, (2021/08/26)
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.
Preparation method of P-tert-butylphenylpropionaldehyde
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, (2020/02/14)
The invention relates to a preparation method of p-tert-butyl phenylpropionaldehyde. The preparation method comprises the following steps: subjecting p-tert-butylbenzaldehyde, alkyl orthoformate and afirst catalyst to mixing and a reaction, then adding vinyl ether, carrying out mixing and a reaction, then adding a second catalyst and a second solvent, performing a hydrolysis reaction, and finallysubjecting obtained supernatant containing a reaction product to catalytic hydrogenation to obtain p-tert-butylphenylpropionaldehyde. Through selection of a specific catalyst, the multi-step reactions of the method provided by the invention can be continuously carried out; separation and extraction of an intermediate product are not needed; the multi-step reactions can be realized in one reactionsystem; according to a technical scheme provided by the invention, the product is prepared from the raw materials through one-pot reactions, and reaction conditions are mild; and the obtained p-tert-butylphenylpropionaldehyde has a content of 70% or above, is colorless transparent oily liquid, and can be directly used for essence preparation, and the highest yield can reach 93.1%.
Organic Ligand-Free Hydroformylation with Rh Particles as Catalyst?
Liu, Shujuan,Dai, Xingchao,Wang, Hongli,Wang, Xinzhi,Shi, Feng
, p. 139 - 143 (2020/01/03)
An efficient and organic ligand-free heterogeneous catalytic system for hydroformylation of olefins is highly desirable for both academy and industry. In this study, simple Rh black was employed as a heterogeneous catalyst for hydroformylation of olefins in the absence of organic ligand. The Rh black catalyst showed good catalytic activity for a broad substrate scope including the aliphatic and aromatic olefins, affording the desired aldehydes in good yields. Taking the hydroformylation of ethylene as an example, 86% yield of propanal and TOF of 200 h–1 were obtained, which was superior to the reported homogeneous catalytic systems. In addition, the catalyst could be reused five times without loss of activity under identical reaction conditions, and the Rh leaching was negligible after each cycle.
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.
Palladium-catalyzed double-bond migration of unsaturated hydrocarbons accelerated by tantalum chloride
Murai, Masahito,Nishimura, Kengo,Takai, Kazuhiko
, p. 2769 - 2772 (2019/03/23)
The operationally simple palladium-catalyzed double-bond migration without heteroatom-containing coordinating functional groups is described. Addition of TaCl5 as a second catalyst greatly enhanced the migration efficiency to provide β-alkylsty
Method for synthesizing 3-(4-tert-butylphenyl)propionaldehyde
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Paragraph 0015; 0016-0019; 0020-0021, (2018/05/16)
The invention discloses a method for synthesizing 3-(4-tert-butylphenyl)propionaldehyde. The method is executed according to reaction formulas as shown in the description and specifically comprises following steps: a compound shown as the formula I is subjected to Claisen-Schmidt condensation reaction, unsaturated aldehydes are produced, and a compound shown as the formula II is obtained; the compound shown as the formula II is dissolved in toluene and ethanediol and subjected to fractional distillation and water discharge under the action of a catalyst, and a compound shown as the formula IIIis produced through condensation; the compound shown as the formula III is dissolved in a solvent, then the catalyst is added, hydrogen is introduced under pressurizing action to reduce double bonds,and a compound shown as the formula IV is obtained; acetal shown as the formula IV is hydrolyzed under the acidic condition to form aldehyde, and 3-(4-tert-butylphenyl)propionaldehyde shown as the formula V is obtained. Compared with Friedel-Crafts acylation reaction in the prior art, the method for synthesizing 3-(4-tert-butylphenyl)propionaldehyde has the advantages as follows: conditions are mild, the Claisen-Schmidt condensation reaction is high in selectivity, unicity of condensation is high, and the problem of severe pollution caused by high consumption of strong-corrosion titanium tetrachloride is solved. The reaction synthesis is low-pollution, aftertreatment is simple, and the requirement of modern green production is met.
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.
