- Binuclear Pd(I)-Pd(I) Catalysis Assisted by Iodide Ligands for Selective Hydroformylation of Alkenes and Alkynes
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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.
- Zhang, Yang,Torker, Sebastian,Sigrist, Michel,Bregovi?, Nikola,Dydio, Pawe?
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supporting information
p. 18251 - 18265
(2020/11/02)
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- Tuning Regioselectivity of Wacker Oxidation in One Catalytic System: Small Change Makes Big Step
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A regioselectivity switchable aerobic Wacker-Tsuji oxidation has been developed using catalytic tert-butyl nitrite as a simple organic redox cocatalyst. By solely switching the solvent, either substituted aldehydes or ketones could be prepared under mild
- Hu, Kang-Fei,Ning, Xiao-Shan,Qu, Jian-Ping,Kang, Yan-Biao
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p. 11327 - 11332
(2018/09/06)
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- Tunable P-Chiral Bisdihydrobenzooxaphosphole Ligands for Enantioselective Hydroformylation
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Air-stable and tunable chiral bisdihydrobenzooxaphosphole ligands (BIBOPs) were employed in rhodium-catalyzed asymmetric hydroformylation of various terminal olefins with excellent conversions (>99%), moderate-to-excellent enantioselectivities (up to 95:5 er), and branched to linear ratios (b:l) of up to 400.
- Tan, Renchang,Zheng, Xin,Qu, Bo,Sader, C. Avery,Fandrick, Keith R.,Senanayake, Chris H.,Zhang, Xumu
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supporting information
p. 3346 - 3349
(2016/07/26)
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- Catalyst-controlled wacker-type oxidation: Facile access to functionalized aldehydes
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The aldehyde-selective oxidation of alkenes bearing diverse oxygen groups in the allylic and homoallylic position was accomplished with a nitrite-modified Wacker oxidation. Readily available oxygenated alkenes were oxidized in up to 88% aldehyde yield and as high as 97% aldehyde selectivity. The aldehyde-selective oxidation enabled the rapid, enantioselective synthesis of an important pharmaceutical agent, atomoxetine. Finally, the influence of proximal functional groups on this anti-Markovnikov reaction was explored, providing important preliminary mechanistic insight.
- Wickens, Zachary K.,Skakuj, Kacper,Morandi, Bill,Grubbs, Robert H.
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supporting information
p. 890 - 893
(2014/02/14)
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- Magnetic nanoparticle supported triphenylphosphine ligand for the Rh-catalyzed hydroformylation reaction
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A magnetic recyclable nano-triphenylphosphine (nano-TPP) ligand was synthesized by simply loading a dopamine-triphenylphosphine derivative onto the surface of super paramagnetic iron oxide nanoparticle (SPION). Via the cooperation between surface neighbor TPP units, nano-TPPs can bond to Rh atoms forming magnetic recyclable nano-TPPRh complexes to catalyze the hydroformylation reaction and can be reused for 20 times with the compensation of Rh salt.
- Duanmu, Chuansong,Wu, Linlin,Gu, Jian,Xu, Xingyou,Feng, Liangdong,Gu, Xu
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- ALDEHYDE-SELECTIVE WACKER-TYPE OXIDATION OF UNBIASED ALKENES
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This disclosure is directed to methods of preparing organic aldehydes, each method comprising contacting a terminal olefin with an oxidizing mixture comprising: (a) a dichloro-palladium complex; (b) a copper complex; (c) a source of nitrite; under aerobic reaction conditions sufficient to convert at least a portion of the terminal olefin to an aldehyde.
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Paragraph 0178-0183
(2014/10/29)
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- Easily accessible and highly tunable bisphosphine ligands for asymmetric hydroformylation of terminal and internal alkenes
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An efficient methodology for synthesizing a small library of easily tunable and sterically bulky ligands for asymmetric hydroformylation (AHF) has been reported. Five groups of alkene substrates have been tested with excellent conversions, moderate-to-excellent regio- and enantioselectivities. Among the best result of the reported literature, application of ligand 1 c in the highly selective AHF of the challenging substrate 2,5-dihydrofuran yielded almost one isomer in up to 99 % conversion along with enantiomeric excesses (ee) of up to 92 %. Highly enantioselective AHF of dihydropyrrole substrates is achieved using the same ligand, with up to 95 % ee and up to >1:50 β-isomer/α- isomer ratio. The simpler the better! An efficient method for the easy and tunable synthesis of a series of asymmetric hydroformylation (AHF) ligands from low-cost, commercially available starting materials has been reported. These ligands can give excellent conversions and moderate to excellent regio- and enantioselectivities for a broad range of mono- and disubstituted alkenes with a low catalyst loading (substrate-to-catalyst ratios (S/C) of 1000:1 to 3000:1).
- Xu, Kun,Zheng, Xin,Wang, Zhiyong,Zhang, Xumu
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p. 4357 - 4362
(2014/05/06)
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- New tetraphosphorus ligands for highly linear selective hydroformylation of allyl and vinyl derivatives
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New tetraphosphorus ligands have been developed and applied in the rhodium-catalyzed regioselective hydroformylation of a variety of functionalized allyl and vinyl derivatives. Remarkably high linear selectivity was obtained by these tetraphosphorus ligands. The ligand that bears strong electron-withdrawing 2,4-difluorophenyl groups is the most effective one in affording linear aldehydes. The Rh/tetraphosphorus ligand catalyst is highly effective to produce linear aldehydes from functionalized allyl derivatives with heteroatoms or aromatic groups directly adjacent to the allyl group. For vinyl derivatives, the ligand is highly linear selective for acrylic derivatives, styrene, vinyl pyridine, and vinyl phthalimide. Linear to branch ratios of 26:1 and 10:1 were obtained for the hydroformylation of styrene and allyl cyanide, respectively. New tetraphosphorus ligands have been developed and applied in the rhodium-catalyzed regioselective hydroformylation of a variety of allyl and vinyl olefins (see scheme). Remarkably high linear selectivities were obtained by these ligands. Linear-to-branch ratios of 26:1 and 10:1 were obtained for the hydroformylation of styrene and allyl cyanide, respectively. Copyright
- Cai, Chaoxian,Yu, Shichao,Cao, Bonan,Zhang, Xumu
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experimental part
p. 9992 - 9998
(2012/09/07)
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- Palladium hydroxide catalyzed transformation of primary propargylic alcohols into aldehydes: Application to the synthesis of the tetrahydrofuran core
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A palladium-catalyzed one-pot, two-step sequence involving redox isomerization/reduction of primary propargylic alcohols into the corresponding aldehydes has been achieved at room temperature for the first time in good to excellent yields under mild conditions. The functional group compatibility in this reaction is studied and this new methodology has been successfully applied in the synthesis of the 2,5-trans-tetrahydrofuran ring system of amphidinolides. It is noteworthy that aromatic substituted propargylic alcohols gave a mixture of unsaturated and saturated aldehydes, whereas aliphatic propargylic alcohols gave only saturated aldehydes. Georg Thieme Verlag Stuttgart · New York.
- Sabitha, Gowravaram,Reddy, A.Yagundar,Nayak, Sambit,Yadav, Jhillu S.
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experimental part
p. 1657 - 1662
(2012/07/03)
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- Rhodium-catalyzed asymmetric hydroformylation of n-allvlamides: Highly enantioselective approach to β2-amino aldehydes
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(Figure Presented) You're having a lahf I The asymmetric hydroformylation (AHF) of allylic compounds, catalyzed by a rhodium-yanphos complex, is a direct and concise route to ss2-amino aldehydes, acids, and alcohols with excellent enantioselectivity (see scheme; TON =turnover number, acac = acetylacetonate).
- Zhang, Xiaowei,Cao, Bonan,Yu, Shichao,Zhang, Xumu
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supporting information; experimental part
p. 4047 - 4050
(2010/08/07)
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- Enantioselective hydroformylation of N-vinyl carboxamides, allyl carbamates, and allyl ethers using chiral diazaphospholane ligands
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Rhodium complexes of diazaphospholane ligands catalyze the asymmetric hydroformylation of N-vinyl carboxamides, allyl ethers, and allyl carbamates; products include 1,2- and 1,3-aminoaldehydes and 1,3-alkoxyaldehydes. Using glass pressure bottles, short reaction times (generally less than 6 h), and low catalyst loading (commonly 0.5 mol %), 20 substrates are successfully converted to chiral aldehydes with useful regioselectivity and high enantioselectivity (up to 99% ee). Chiral Roche aldehyde is obtained with 97% ee from the hydroformylation of allyl silyl ethers. Commonly difficult substrates such as 1,1- and 1,2-disubstituted alkenes undergo effective hydroformylation with 89-97% ee and complete conversion for six examples. Palladium-catalyzed aerobic oxidative amination of allyl benzyl ether followed by enantioselective hydroformylation yields the β3-aminoaldehyde with 74% ee.
- McDonald, Richard I.,Wong, Gene W.,Neupane, Ram P.,Stahl, Shannon S.,Landis, Clark R.
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supporting information; experimental part
p. 14027 - 14029
(2011/01/04)
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- Hydroformylation of olefins catalyzed by rhodium complexes with phosphinitecalix[4]arenes
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Hydroformylation of alkenes with various carbon chain lengths and arylalkenes in the presence of the catalytic system consisting of Rh(acac)(CO)2 and phosphinitecalix[4]arenes was studied. The influence of the P/Rh and substrate/catalyst ratios, temperature, and pressure on the process and the product composition was examined.
- Karakhanov,Kardasheva,Runova,Terenina,Shadrova
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p. 340 - 344
(2008/09/17)
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- Reactions of Weinreb amides: formation of aldehydes by Wittig reactions
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Aldehydes are prepared in excellent yield by Wittig reactions of phosphoranes on the Weinreb amide of formic acid followed by in situ hydrolysis.
- Hisler, Kevin,Tripoli, Regis,Murphy, John A.
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p. 6293 - 6295
(2007/10/03)
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- Catalytic systems based on sulfocalixarenes in the hydroformylation of alkenes
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The hydroformylation of unsaturated compounds was examined in aqueous-organic media using a new catalyst system consisting of acetylacetonatodicarbonylrhodium, triphenylphosphine, and sulfonated calixarenes.
- Karakhanov,Kardasheva,Runova,Terenina
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p. 181 - 183
(2007/10/03)
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- 1,5-Hydrogen transfers from carbon to N-tributyltin substituted nitrogen
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1,5-H transfers from carbon to N-tributyltin substituted nitrogen proceeded smoothly and were much more efficient than 1,5-H transfers from carbon to ordinary nitrogen. 1,5-Tribuyltin group transfer from carbon to nitrogen and intramolecular addition of an aminyl radical to a nitrile group were also observed for the first time.
- Kim, Sunggak,Yeon, Kyu Man,Yoon, Kwang Sub
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p. 3919 - 3922
(2007/10/03)
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- Hydroxyalkylation with α-Hydroperoxydiazenes. Alcohols from Olefins and Carbonyl Compounds from Enol Ethers
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Alkyl(1-hydroxy-1-methylethyl)diazenes 2a-f were prepared in solution by autoxidation of the corresponding hydrazones of acetone.Thermolysis of the diazenes at 50-80 deg C in alkenes leads to alcohols.For example, 2b decomposes in 1,1-diphenylethene to afford 5-hydroxy-5,5-diphenylpentanenitrile.Alkenes with abstractable allylic hydrogens gave analogous products, but in very low yield.Thermolysis of a diazene 2 in an enol ether solvent leads to an aldehyde or a ketone.Thus, 2a decomposes in 1-ethoxyethene and in 2-methoxypropene to afford, respectively, 4,4,4-trifluorobutanal and 5,5,5-trifluoro-2-pentanone.Yields lie in range from 50percent to 70percent.The thermolysis of 2 in alkenes involves radical intermediates and radical chain hydroxyalkylation of alkene double bonds.In one chain-propagating step, R*, generated from 2, adds to the alkene.The adduct radical so formed propagates by inducing decomposition of 2 by attack at hydroxyl oxygen.According to this mechanism, initial products from enol ethers are hemiacetals or hemiketals which do not survive the reaction conditions but decompose to the corresponding carbonyl compounds.Preliminary evidence for this mechanism is presented.
- Osei-Twum, Emmanuel Y.,McCallion, Doug,Nazran, Avtar S.,Panicucci, Rick,Risbood, Prabhakar A.,Warkentin, John
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p. 336 - 342
(2007/10/02)
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