- Redox-active ligand based Mn(i)-catalyst for hydrosilylative ester reduction
-
Herein a Mn(i) catalyst bearing a redox-active phenalenyl (PLY) based ligand is reported for the efficient hydrosilylation of esters to alcohols using the inexpensive silane source polymethylhydrosiloxane (PMHS) under mild conditions. Mechanistic investigations suggest a strong ligand-metal cooperation where a ligand-based single electron transfer (SET) process initiates the reaction through Si-H bond activation.
- Chakraborty, Soumi,Das, Arpan,Mandal, Swadhin K.
-
supporting information
p. 12671 - 12674
(2021/12/04)
-
- Deoxygenative hydroboration of primary, secondary, and tertiary amides: Catalyst-free synthesis of various substituted amines
-
Transformation of relatively less reactive functional groups under catalyst-free conditions is an interesting aspect and requires a typical protocol. Herein, we report the synthesis of various primary, secondary, and tertiary amines through hydroboration of amides using pinacolborane under catalyst-free and solvent-free conditions. The deoxygenative hydroboration of primary and secondary amides proceeded with excellent conversions. The comparatively less reactive tertiary amides were also converted to the corresponding N,N-diamines in moderate yields under catalyst-free conditions, although alcohols were obtained as a minor product.
- An, Duk Keun,Jaladi, Ashok Kumar,Kim, Hyun Tae,Yi, Jaeeun
-
-
- A Bifunctional Copper Catalyst Enables Ester Reduction with H2: Expanding the Reactivity Space of Nucleophilic Copper Hydrides
-
Employing a bifunctional catalyst based on a copper(I)/NHC complex and a guanidine organocatalyst, catalytic ester reductions to alcohols with H2 as terminal reducing agent are facilitated. The approach taken here enables the simultaneous activation of esters through hydrogen bonding and formation of nucleophilic copper(I) hydrides from H2, resulting in a catalytic hydride transfer to esters. The reduction step is further facilitated by a proton shuttle mediated by the guanidinium subunit. This bifunctional approach to ester reductions for the first time shifts the reactivity of generally considered "soft"copper(I) hydrides to previously unreactive "hard"ester electrophiles and paves the way for a replacement of stoichiometric reducing agents by a catalyst and H2.
- Kaicharla, Trinadh,Ngoc, Trung Tran,Teichert, Johannes F.,Tzaras, Dimitrios-Ioannis,Zimmermann, Birte M.
-
supporting information
p. 16865 - 16873
(2021/10/20)
-
- Potassium Fluoride-Catalyzed Hydroboration of Aldehydes and Ketones: Facile Reduction to Primary and Secondary Alcohols
-
A catalytic hydroboration of various ketones and aldehydes can be achieved in the presence of inexpensive and commercially available inorganic salts containing fluoride anion. As a result, the reduction of carbonyl moieties to the corresponding primary and secondary alcohols can be achieved at room temperature under mild conditions.
- Kuciński, Krzysztof,Hreczycho, Grzegorz
-
supporting information
p. 552 - 555
(2020/02/04)
-
- Palladium-Catalyzed Selective Reduction of Carbonyl Compounds
-
Two new examples of structurally characterized β-diketiminate analogues i.e., conjugated bis-guanidinate (CBG) supported palladium(II) complexes, [LPdX]2; [L= {(ArHN)(ArN)–C=N–C=(NAr)(NHAr)}; Ar = 2,6-Et2-C6H3], X = Cl (1), Br (2) have been reported. The synthesis of complexes 1–2 was achieved by two methods. Method A involves deprotonation of LH by nBuLi followed by the treatment of LLi (insitu formed) with PdCl2 in THF, which afforded compound 1 in good yield (75 %). In Method B, the reaction between free LH and PdX2 (X = Cl or Br) in THF allowed the formation of complexes 1 (Yield 73 %) and 2 (Yield 52 %), respectively. Moreover, these complexes were characterized thoroughly by several spectroscopic techniques (1H, 13C NMR, UV/Vis, FT-IR, and HRMS), including single-crystal X-ray structural and elemental analyses. In addition, we tested the catalytic activity of these complexes 1–2 for the hydroboration of carbonyl compounds with pinacolborane (HBpin). We observed that compound 1 exhibits superior catalytic activity when compared to 2. Compound 1 efficiently catalyzes various aldehydes and ketones under solvent-free conditions. Furthermore, both inter- and intramolecular chemoselectivity hydroboration of aldehydes over other functionalities have been established.
- Sarkar, Nabin,Mahato, Mamata,Nembenna, Sharanappa
-
p. 2295 - 2301
(2020/05/18)
-
- Erratum: Redox-Noninnocent Ligand-Supported Vanadium Catalysts for the Chemoselective Reduction of C=X (X = O, N) Functionalities (Journal of the American Chemical Society (2019) 141:38 (15230-15239) DOI: 10.1021/jacs.9b07062)
-
Pages 15232, 15233, and 15236. In the original paper, the doublet wave functions for 21 and 21a/21b were incorrectly (Figure Presented). reported as spin-contaminated in sections 2.3 and 2.8 (Figure 3 and Scheme 9, respectively.) This comes from the incorrectly reported expected eigenvalue of 0.75 for the spin-squared operator ??2? for the antiferromagnetically coupled doublet |↓?L|↑↑?V state (originally given in the Supporting Information). The correct expected eigenvalue for the |↓?L|↑↑?V state should be 1.75. The wave functions for 21 and 21a/21b (eigenvalues 1.79 and 1.77/1.66, respectively) are therefore not spincontaminated. The corrected Figure 3 and Scheme 9 are presented below. A corrected Supporting Information file is also provided. The corrections do not affect any of the conclusions of the Article, but slightly decrease the gap between the quartet and doublet spin surfaces. Scheme 3 has been also corrected to reflect the fact that (CH3)3SiCH2 ? radicals can only react based on spin conservation.
- Zhang, Guoqi,Wu, Jing,Zheng, Shengping,Neary, Michelle C.,Mao, Jincheng,Flores, Marco,Trovitch, Ryan J.,Dub, Pavel A.
-
supporting information
p. 16507 - 16509
(2020/10/14)
-
- Ruthenium-catalyzed ester reductions applied to pharmaceutical intermediates
-
Ruthenium pincer complexes were synthesized and used for catalytic ester reductions under mild conditions (~5 bar of hydrogen). An experimental design approach was used to optimize the conditions for yield, purity, and robustness. Evidence for the catalytically active ruthenium dihydride species is presented. Observed intermediates and side products, as well as time-course data, were used to build mechanistic insight. The optimized procedure was further demonstrated through scaled-up reductions of two pharmaceutically relevant esters, both in batch and continuous flow.
- Shaalan, Youssef,Boulton, Lee,Jamieson, Craig
-
supporting information
p. 2745 - 2751
(2020/11/30)
-
- MUSCARINIC AGONISTS AS NON-STEROIDAL AND NON-OPIOID ANALGESICS AND METHODS OF USE THEREOF
-
Novel Gi/o-biased muscarinic agonists selectively activate only one specific signaling pathway and are novel pharmacophores for development of new painkillers (analgesics). Methods of making and using these agonists are also described.
- -
-
Paragraph 0060; 0073; 0076; 00106
(2020/09/19)
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- Selective Hydroboration of Carboxylic Acids with a Homogeneous Manganese Catalyst
-
Catalytic reduction of carboxylic acid to the corresponding alcohol is a challenging task of great importance for the production of a variety of value-added chemicals. Herein, a manganese-catalyzed chemoselective hydroboration of carboxylic acids has been developed with a high turnover number (>99?000) and turnover frequency (>2000 h-1) at 25 °C. This method displayed tolerance of electronically and sterically differentiated substrates with high chemoselectivity. Importantly, aliphatic long-chain fatty acids, including biomass-derived compounds, can efficiently be reduced. Mechanistic studies revealed that the reaction occurs through the formation of active manganese-hydride species via an insertion and bond metathesis type mechanism.
- Barman, Milan K.,Das, Kuhali,Maji, Biplab
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p. 1570 - 1579
(2019/01/30)
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- Practical and selective hydroboration of aldehydes and ketones in air catalysed by an iron(ii) coordination polymer
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The in air catalytic hydroboration of ketones and aldehydes with pinacolborane by an iron(ii) coordination polymer (CP) is carried out under mild and solvent-free conditions. The precatalyst is highly active towards a wide range of substrates including functionalized ketones and aldehydes in the presence of KOtBu as an activator, achieving a high turnover number (TON) of up to 9500. Excellent chemoselectivity to aldehydes over ketones was also revealed, which is in sharp contrast with the results obtained under inert atmosphere using the same catalyst system. This catalyst observed here is not only highly efficient but also recyclable for reuse for at least 5 times without losing its effectiveness.
- Zhang, Guoqi,Cheng, Jessica,Davis, Kezia,Bonifacio, Mary Grace,Zajaczkowski, Cynthia
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p. 1114 - 1121
(2019/03/12)
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- Lithium triethylborohydride as catalyst for solvent-free hydroboration of aldehydes and ketones
-
Commercially available and inexpensive lithium triethylborohydride (LiHBEt3) acts as efficient catalyst for the solvent-free hydroboration of a wide range of aldehydes and ketones, which were subsequently transformed to corresponding 1° and 2° alcohols in one-pot procedure at room temperature (rt).
- Kuciński, Krzysztof,Hreczycho, Grzegorz
-
supporting information
p. 1912 - 1915
(2019/04/27)
-
- Catalytic removal of tert-butyldimethylsilyl (TBS) ether by PVP-I
-
A mild, efficient and rapid protocol the deprotection of alcoholic TBDMS ethers using PVP-1 as catalyst in methanol, the procedure of deprotection of various TBDMS ethers were found to be very convenient, easy work-up, high yielding.
- Ke, Yanxiong,Lu, Guangying,Ren, Jiangmeng,Wang, Di,Zeng, Bu-Bing
-
-
- Enzymatic One-Step Reduction of Carboxylates to Aldehydes with Cell-Free Regeneration of ATP and NADPH
-
The direct generation of aldehydes from carboxylic acids is often a challenging synthetic task but undoubtedly attractive in view of abundant supply of such feedstocks from nature. Though long known, biocatalytic carboxylate reductions are at an early stage of development, presumably because of their co-factor requirement. To establish an alternative to whole-cell-based carboxylate reductions which are limited by side reactions, we developed an in vitro multi-enzyme system that allows for quantitative reductions of various carboxylic acids with full recycling of all cofactors and prevention of undesired over-reductions. Regeneration of adenosine 5′-triphosphate is achieved through the simultaneous action of polyphosphate kinases from Meiothermus ruber and Sinorhizobium meliloti and β-nicotinamide adenine dinucleotide 2′-phosphate is reduced by a glucose dehydrogenase. Under these conditions and in the presence of the carboxylate reductases from Neurospora crassa or Nocardia iowensis, various aromatic, heterocyclic and aliphatic carboxylic acids were quantitatively reduced to the respective aldehydes.
- Strohmeier, Gernot A.,Eitelj?rg, Inge C.,Schwarz, Anna,Winkler, Margit
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p. 6119 - 6123
(2019/04/13)
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- Aluminum Hydroxide Secondary Building Units in a Metal-Organic Framework Support Earth-Abundant Metal Catalysts for Broad-Scope Organic Transformations
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The intrinsic heterogeneity of alumina (Al2O3) surface presents a challenge for the development of alumina-supported single-site heterogeneous catalysts and hinders the characterization of catalytic species at the molecular level as well as the elucidation of mechanistic details of the catalytic reactions. Here we report the use of aluminum hydroxide secondary building units (SBUs) in the MIL-53(Al) metal-organic framework (MOF) with the formula Al(μ2-OH)(BDC) (BDC = 1,4-benzenedicarboxylate) as a uniform and structurally defined functional mimic of Al2O3 surface for supporting Earth-abundant metal (EAM) catalysts. The μ2-OH groups in MIL-53(Al) SBUs were readily deprotonated and metalated with CoCl2 and FeCl2 to afford MIL-53(Al)-CoCl and MIL-53(Al)-FeCl precatalysts which were characterized by powder X-ray diffraction, nitrogen sorption, elemental analysis, density functional theory, and extended X-ray fine structure spectroscopy. Activation with NaBEt3H converted MIL-53(Al)-CoCl to MIL-53(Al)-CoH which effectively catalyzed hydroboration of alkynes and nitriles and hydrosilylation of esters. X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopy (XANES) indicated the presence of AlIII and CoII centers in MIL-53(Al)-CoH while deuterium labeling studies suggested σ-bond metathesis as a key step for the MIL-53(Al)-CoH-catalyzed addition reactions. MIL-53(Al)-FeCl competently catalyzed oxidative Csp3-H amination and Wacker-type alkene oxidation. XANES analysis revealed the oxidation of FeII to FeIII centers in the activated MIL-53(Al)-FeCl catalyst and suggested that oxidative Csp3-H amination occurs via the formation of FeIII-OtBu species by single electron transfer between FeII centers in MIL-53(Al)-FeCl and (tBuO)2 with concomitant generation of 1 equiv of tBuO· radical, C-H activation through hydrogen atom abstraction to generate alkyl radicals, protonation of FeIII-OtBu by aniline to generate MIL-53(Al)-FeIII-anilide, and finally C-N coupling between the FeIII-anilide and alkyl radical to form the Csp3-H amination product and regenerate the FeII catalyst. These highly active single-site MOF-based solid catalysts were readily recovered and reused up to five times without significant decrease in catalytic activity. This work thus demonstrates the great potential of using the aluminum hydroxide SBUs in MOFs to support EAM catalysts for important organic transformations.
- Feng, Xuanyu,Ji, Pengfei,Li, Zhe,Drake, Tasha,Oliveres, Pau,Chen, Emily Y.,Song, Yang,Wang, Cheng,Lin, Wenbin
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p. 3327 - 3337
(2019/03/26)
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- Regio- A nd chemoselective deprotection of primary acetates by zirconium hydrides
-
A combination of DIBAL-H and Cp2ZrCl2 is shown to promote the regioselective cleavage of primary acetates on a broad scope of substrates, ranging from carbohydrates to terpene derivatives, with a high tolerance toward protecting groups and numerous functionalities found in natural products and bioactive compounds. Apart from providing highly valuable building blocks in only two steps from biosourced raw materials, this selective de-O-acetylation should also be strongly helpful to solve selectivity issues in organic synthesis.
- Gavel, Marine,Courant, Thibaut,Joosten, Antoine Yvan Philippe,Lecourt, Thomas
-
supporting information
p. 1948 - 1952
(2019/04/10)
-
- Microwave-assisted Cannizzaro reaction—Optimisation of reaction conditions
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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.
- Janczewski, ?ukasz,Walczak, Ma?gorzata,Fr?czyk, Justyna,Kamiński, Zbigniew J.,Kolesińska, Beata
-
supporting information
p. 3290 - 3300
(2019/11/05)
-
- Cobalt(II) Coordination Polymer as a Precatalyst for Selective Hydroboration of Aldehydes, Ketones, and Imines
-
Highly effective hydroboration precatalyst is developed based on a cobalt(II)-terpyridine coordination polymer (CP). The hydroboration of ketones, aldehydes, and imines with pinacolborane (HBpin) has been achieved using the recyclable CP catalyst in the presence of an air-stable activator. A wide range of substrates containing polar C=O or C=N bonds have been hydroborated selectively in excellent yields under ambient conditions.
- Wu, Jing,Zeng, Haisu,Cheng, Jessica,Zheng, Shengping,Golen, James A.,Manke, David R.,Zhang, Guoqi
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p. 9442 - 9448
(2018/07/05)
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- Lanthanide aryloxides catalyzed hydroboration of aldehydes and ketones
-
The lanthanide aryloxides Ln(OAr)3(THF)2 (Ar = Ar1 = 2,6-tBu2-4-MeC6H2, Ln = Yb (1), Y (2); Ar = Ar2 = 2,6-iPr2C6H3, Ln = Y (3); Ar = Ar3 = 2,6-Me2C6H3, Ln = Y (4); Ar = Ar1, Ln = Sm (5), Nd (6)) could be served as highly efficient catalysts for the hydroboration of aldehydes and ketones with good functional group tolerance and excellent chemoselectivity. Computational studies were carried out to probe a feasible mechanism of the Ln-aryloxides catalyzed hydroboration of aldehydes/ketones.
- Zhu, Zhangye,Dai, Ping,Wu, Zhenjie,Xue, Mingqiang,Yao, Yingming,Shen, Qi,Bao, Xiaoguang
-
-
- Magnesium oxide supported bimetallic Pd/Cu nanoparticles as an efficient catalyst for Sonogashira reaction
-
PdCu bimetallic nanoparticles with a diameter of about 3 nm are prepared and supported on a polymeric vinylimidazole ligand modified magnesium oxide. This new material is characterized using different analysis such as XRD, XPS, CHNS, TEM, SEM, and EDX-mapping. PdCu supported on MgO (MgO@PdCu) exhibits high catalytic activity in the Sonogashira coupling reaction of aryl iodides, bromides and chlorides with low Pd loading (0.05-0.2 mol%). This catalyst is recovered and recycled for 11 consecutive runs preserving its catalytic activity in the model reaction of iodobenzene with phenylacetylene for at least 8 cycles. Reused catalyst is characterized with TEM, XPS and EDX showing preservation of the catalyst structure. Using hot filtration and PVP poisoning tests, the catalyst shows a heterogeneous behavior for the model reaction.
- Gholinejad, Mohammad,Bahrami, Maedeh,Nájera, Carmen,Pullithadathil, Biji
-
-
- METHOD FOR PRODUCING 1,2,4-OXADIAZOLE DERIVATIVE
-
The invention provides a production method of a 1,2,4-oxadiazole derivative represented by formula (A), which comprises reacting a compound represented by formula (B) and a compound represented by formula (C) in the presence of a basic compound: wherein Ar is an aromatic group or an aromatic group having substituent(s); W, X, Y and Z are each independently —S—, —N═, —CH═ or —CR═, and one selected from W, X, Y and Z is —S—; and R is an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a haloalkyl group having 1 to 3 carbon atoms, a haloalkoxy group having 1 to 3 carbon atoms or a halogen atom.
- -
-
Paragraph 0144
(2018/03/01)
-
- Nickel boride mediated chemoselective deprotection of 1,1-diacetates to aldehydes and deprotection with concomitant reduction to alcohols at ambient temperature
-
A variety of 1,1-diacetates have been chemoselectively and efficiently deprotected to the corresponding aldehydes as well as deprotected and concomitantly reduced to the corresponding alcohols in high yields at ambient temperature with nickel boride generated in situ using different molar ratios of sodium borohydride and nickel (II) chloride in methanol at room temperature. Deprotection and reduction of a variety of aromatic, aliphatic and heterocyclic acylals have been achieved efficiently. Mild reaction conditions, easy work-up, high yields and chemoselectivity demonstrate the efficiency of this new method.
- Bartwal, Gaurav,Saroha, Mohit,Khurana, Jitender.M.
-
-
- Substituted pyrazolopyridine derivatives and medicinal use thereof
-
The invention relates to substituted pyrazolopyridine derivatives represented by formula (I), and pharmaceutically acceptable salts, isomers, prodrugs and medicinal compositions thereof. Above compounds are stimulants of soluble guanylate cyclase. In the formula (I), R1 represents a thienyl group or a substituted pyridyl group, R2 represents -NH2, -NHCH3 or -NHC(=O)CH(CH3)2, R3 represents hydrogenor a C1-C4 alkyl group, and R4 represents a C1-C6 alkyl group. The invention also discloses a preparation method of the compounds and an application of the compounds as medicines, especially an application as cardiovascular disease treatment medicines, such as anti-pulmonary arterial hypertension medicines.
- -
-
Paragraph 0050; 0054; 0055
(2018/05/07)
-
- IRIDIUM-BASED CATALYSTS FOR HIGHLY EFFICIENT DEHYDROGENATION AND HYDROGENATION REACTIONS IN AQUEOUS SOLUTION AND APPLICATIONS THEREOF
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A series of iridium-based catalysts for dehydrogenation of formic acid, and hydrogenation using formic acid as the hydrogen source, and the process using the catalyst(s) to produce hydrogen gas from formic acid solution, or to reduce aldehydes using formic acid, are disclosed and claimed. More specifically, the present invention relates to a group of pentamethylcyclopentadienyl (Cp*) iridium complexes with different Ν,Ν-bidentate ligands that catalyze dehydrogenation from formic acid, and chemo-selective hydrogenation of aldehydes, in the aqueous solution system in a highly efficient, and long life-time manner.
- -
-
Page/Page column 13; 17
(2018/11/22)
-
- Solvent-free mechanochemical oxidation and reduction of biomass-derived 5-hydroxymethyl furfural
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The simultaneous synthesis of 5-hydroxymethyl-2-furoic acid and 2,5-hydroxymethylfuran from biomass-derived 5-hydroxymethyl furan was developed using a solvent-free mechanochemical approach. The results obtained for the Cannizzaro disproportionation reaction show quantitative conversions of the starting materials with reaction times of only 5 min. Employing solvent-free conditions allows for a more sustainable synthetic approach that is reflected in an Efactor 7 times smaller than that in previous reports. Additionally, initial results of the use of a sacrificial reagent, with the same solvent-free mechanochemical approach, for the selective reduction and oxidation of HMF are presented.
- Chacón-Huete,Messina,Chen,Cuccia,Ottenwaelder,Forgione
-
p. 5261 - 5265
(2018/12/05)
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- Chemoenzymatic one-pot reaction of noncompatible catalysts: Combining enzymatic ester hydrolysis with Cu(i)/bipyridine catalyzed oxidation in aqueous medium
-
The combination of chemical catalysts and biocatalysts in a one-pot reaction has attracted considerable interest in the past years. However, since each catalyst requires very different reaction conditions, chemoenzymatic one-pot reactions in aqueous media remain challenging and are limited today to metal-catalysts that display high activity in aqueous media. Here, we report the first combination of two incompatible catalytic systems, a lipase based ester hydrolysis with a water-sensitive Cu/bipyridine catalyzed oxidation reaction, in a one-pot reaction in aqueous medium (PBS buffer). Key to the solution was the compartmentalization of the Cu/bipyridine catalyst in a core-shell like nanoparticle. We show the synthesis and characterization of the Cu/bipyridine functionalized nanoparticles and the application in the oxidation of allylic and benzylic alcohols in aqueous media. Furthermore, the work demonstrates the implementation of a one-pot reaction process with optimized reaction conditions involving a lipase (CAL-B) to hydrolyze various acetate ester substrates in the first step, followed by oxidation of the resulting alcohols to the corresponding aldehydes under aerobic conditions in aqueous media.
- Sand, Henning,Weberskirch, Ralf
-
p. 33614 - 33626
(2017/07/12)
-
- A Versatile Iridium(III) Metallacycle Catalyst for the Effective Hydrosilylation of Carbonyl and Carboxylic Acid Derivatives
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A versatile iridium(III) metallacycle catalysed rapidly and selectively the reduction of a large array of challenging esters and carboxylic acids as well as various ketones and aldehydes. The reactions proceeded in high yields at room temperature by hydrosilylation followed by desilylation. Although the reactions of various aldehydes and ketones resulted exclusively in alcohols, the hydrosilylation of esters led to alcohols or ethers, depending on the type of substrate. Regarding the carboxylic acids, again the nature of the reagent controlled the outcome of the hydrosilylation reaction, either alcohols or aldehydes being formed.
- Corre, Yann,Rysak, Vincent,Trivelli, Xavier,Agbossou-Niedercorn, Francine,Michon, Christophe
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p. 4820 - 4826
(2017/09/07)
-
- Scandium as a pre-catalyst for the deoxygenative allylation of benzylic alcohols
-
Scandium triflate is an effective pre-catalyst for the deoxygenative allylation of benzylic alcohols with a narrow substrate window. The reaction is shown to proceed through a "hidden Br?nsted acid" mechanism. The reaction is efficient provided that the aryl group is neither too electron rich nor too electron poor. It is shown that this allows useful selectivity. The reaction also works for benzyhydryl alcohols with broader scope. The reaction may also be catalysed by Nafion.
- ?oli?, Ivan,Seankongsuk, Pattarakiat,Loh, Joanna Kejun,Vilaivan, Tirayut,Bates, Roderick W.
-
supporting information
p. 119 - 123
(2017/12/27)
-
- COMPOSITIONS AND METHODS FOR REDUCTION OF KETONES, ALDEHYDES AND IMINIUMS, AND PRODUCTS PRODUCED THEREBY
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A method of producing an alcohol, comprises reducing an aldehyde or a ketone with a hydridosilatrane. The reducing is carried out with an activator.
- -
-
Paragraph 0076-0077
(2018/01/20)
-
- Highly Selective Hydroboration of Alkenes, Ketones and Aldehydes Catalyzed by a Well-Defined Manganese Complex
-
Well-defined manganese complexes based on inexpensive, readily available ligands, 2,2′:6′,2′′-terpyridine and its derivatives have been prepared and employed for the selective hydroboration of alkenes, ketones and aldehydes. Highly Markovnikov regioselective hydroboration of styrenes as well as excellent chemoselective hydroboration of ketones over alkenes were achieved, for the first time, by an earth-abundant manganese catalyst.
- Zhang, Guoqi,Zeng, Haisu,Wu, Jing,Yin, Zhiwei,Zheng, Shengping,Fettinger, James C.
-
supporting information
p. 14369 - 14372
(2016/11/11)
-
- Aluminum Monohydride Catalyzed Selective Hydroboration of Carbonyl Compounds
-
The well-defined aluminum monohydride compound [{(2,4,6-Me3-C6H2)NC(Me)}2(Me)(H)]AlH·(NMe2Et) (1) catalyzes hydroboration of a wide range of aldehydes and ketones under mild reaction conditions. Moreover, compound 1 displayed chemoselective hydroboration of aldehydes over ketones at rt.
- Jakhar, Vineet Kumar,Barman, Milan Kr.,Nembenna, Sharanappa
-
supporting information
p. 4710 - 4713
(2016/09/28)
-
- Synthesis, characterization and reactivity of iron- and cobalt-pincer complexes
-
The tBuPONOP (2,6-bis(di-tert-butyl-phosphinito)pyridine) complexes of iron and cobalt, (tBuPONOP)FeCl2 (1) and (tBuPONOP)CoCl2 (2)) have been prepared. Both complexes are paramagnetic and the solid-state structures of 1 and 2 were determined by single crystal X-ray diffraction studies. Analogous Fe and Co complexes of the tBuPNP (2,6-bis(di-tert-butyl-phosphinomethyl)pyridine) ligand (3 and 4, respectively) were prepared to allow comparison between the closely related pincer ligands in the hydrosilylation of carbonyl moieties. All four complexes were found to be catalytically active when treated with NaBEt3H, which was assumed to generate a metal-hydride species in-situ.
- Smith, Ashleigh D.,Saini, Anu,Singer, Laci M.,Phadke, Neha,Findlater, Michael
-
p. 286 - 291
(2016/07/06)
-
- A General, Practical Triethylborane-Catalyzed Reduction of Carbonyl Functions to Alcohols
-
A combination of the abundant and low-cost triethylborane and sodium alkoxide generates a highly efficient catalyst for reduction of esters, as well as ketones and aldehydes, to alcohols using an inexpensive hydrosilane under mild conditions. The catalyst system exhibits excellent chemoselectivity and a high level of functional group tolerance. Mechanistic studies revealed a resting state of sodium triethylalkoxylborate that is the product of the reaction of BEt3 with sodium alkoxide. This borate species reacts with hydrosilane to form NaBEt3H, which rapidly reduces esters.
- Peng, Dongjie,Zhang, Mintao,Huang, Zheng
-
supporting information
p. 14737 - 14741
(2015/10/19)
-
- Iron-Catalyzed Hydrosilylation of Aldehydes and Ketones under Solvent-Free Conditions
-
Exposure of aldehyde or ketone to 1 mol % BIAN-Fe(C7H8) complex in the presence of diphenyl silane affords the corresponding protected alcohol in excellent yields, under mild reaction conditions. Aldehydes and ketones are reduced cleanly in the presence of a broad range of functional groups under solvent-free conditions.
- Wekesa, Francis S.,Arias-Ugarte, Renzo,Kong, Lydia,Sumner, Zachary,McGovern, Gregory P.,Findlater, Michael
-
p. 5051 - 5056
(2015/11/09)
-
- Boron-Catalyzed N-Alkylation of Amines using Carboxylic Acids
-
A boron-based catalyst was found to catalyze the straightforward alkylation of amines with readily available carboxylic acids in the presence of silane as the reducing agent. Various types of primary and secondary amines can be smoothly alkylated with good selectivity and good functional-group compatibility. This metal-free amine alkylation was successfully applied to the synthesis of three commercial medicinal compounds, Butenafine, Cinacalcet. and Piribedil, in a one-pot manner without using any metal catalysts.
- Fu, Ming-Chen,Shang, Rui,Cheng, Wan-Min,Fu, Yao
-
supporting information
p. 9042 - 9046
(2015/08/03)
-
- Hydrogenations without hydrogen: Titania photocatalyzed reductions of maleimides and aldehydes
-
A mild procedure for the reduction of electron-deficient alkenes and carbonyl compounds is described. UVA irradiations of substituted maleimides with dispersions of titania (Aeroxide P25) in methanol/acetonitrile (1:9) solvent under dry anoxic conditions led to hydrogenation and production of the corresponding succinimides. Aromatic and heteroaromatic aldehydes were reduced to primary alcohols in similar titania photocatalyzed reactions. A mechanism is proposed which involves two proton-coupled electron transfers to the substrates at the titania surface.
- Manley, David W.,Buzzetti, Luca,MacKessack-Leitch, Andrew,Walton, John C.
-
p. 15324 - 15338
(2015/01/16)
-
- Metal-free, visible-light photoredox catalysis: Transformation of arylmethyl bromides to alcohols and aldehydes
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A mild, simple, and controllable metal-free photocatalytic system for the transformation of arylmethyl bromides to corresponding alcohols and aldehydes in high yields with visible-light irradiation has been achieved. Eosin Y was found to be an efficient promoter for this oxidative dehalogenation reaction under photo irradiation conditions.
- Li, Jian,Wang, Hongni,Liu, Li,Sun, Jiangtao
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p. 49974 - 49978
(2014/12/10)
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- NaBH4-TMEDA and a palladium catalyst as efficient regio- and chemoselective system for the hydrodehalogenation of halogenated heterocycles
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The pair NaBH4-TMEDA as hydride source and a palladium catalyst in THF prove to be an efficient system for the hydrodehalogenation of halogenated heterocycles with one or more heteroatoms. In general, Pd(OAc) 2-PPh3 rapidly hydrodehalogenates reactive halo-heterocycles such as bromo-pyridines, -quinolines, -thiophenes, -indoles, -imidazoles, etc., at room temperature in very good yields, whereas in most cases PdCl2(dppf) reduces less reactive halides such as chloro-pyridines, -quinolines, -pyrimidines and bromo-indoles, -benzofurans, etc. Moreover, PdCl2(tbpf) shows to be even more active removing the 2- and 5-chlorine from both thiophene and thiazole rings. The reaction conditions tolerate various functional groups, allowing highly chemoselective reactions in the presence of halide, ester, alkyne, alkene and nitrile substituents. Moreover, with a proper selection of the catalyst it is also possible to obtain a good control in the regioselective hydrodehalogenation of a variety of polyhalogenated substrates.
- Chelucci, Giorgio,Figus, Susanna
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p. 191 - 209
(2014/07/21)
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- HETEROCYCLIC RESORCINOL DERIVATIVES, PREPARATION OF SAME AND COSMETIC USES THEREOF
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The invention relates to a compound of general formula (I) characterized in that: R1 is a C1-C4 alkyl group, andR2 is an optionally substituted nitrogen, sulfur or oxygen containing heteroaromatic ring.
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Paragraph 0039 - 0041
(2014/03/24)
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- Chemoselective ruthenium-catalysed reduction of carboxylic acids
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A very general and efficient catalytic protocol for the selective reduction of carboxylic acids to their corresponding alcohols under mild conditions is described. Various carboxylic acids, including benzoic acids, were reduced in good yields using the presented methodology. The ruthenium-catalysed method yields a highly chemoselective reduction permitting the reduction of a carboxylic acid functionality in the presence of numerous other potentially reducible moieties.
- Fernandez-Salas, Jose A.,Manzini, Simone,Nolan, Steven P.
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supporting information
p. 308 - 312
(2014/05/20)
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- π-Excess σ2P ligands: Synthesis of biaryl-type 1,3-benzazaphosphole hybrid ligands and formation of P^P′-M(CO) 4 chelate complexes
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Acid-catalyzed cyclocondensations of 2-phosphanylanilines 1 with substituted benzaldehydes or heteroaryl aldehydes open a convenient route to new biaryl-type 1H-1,3-benzazaphosphole hybrid ligands 2a-f with o-phosphanylphenyl, pyridyl, imidazolyl, thienyl or o-methoxyphenyl donor groups (in addition to the σ2P donor) and to bromophenyl substituted benzazaphospholes 2g,h. Excess aldehyde leads to concomitant reductive N-alkylation, as shown by formation of 3h besides 2h. The reactions proceed via dihydrobenzazaphospholes 4, which can be detected under mild conditions. The aromaticity-driven dehydrogenation does not liberate dihydrogen but is accomplished by transfer hydrogenations, mainly by reduction of some of the aldehyde. N-Secondary 2-phosphanylanilines 5 also react with aldehydes to form the corresponding N-substituted benzazaphospholes 6. The formation of (P^P′)M(CO)4-chelate complexes 8a (M = Cr) and 9a,b (M = Mo) was demonstrated by reaction with M(CO)4(norbornadiene). The crystal structure of 9a, determined in addition to the solution structure elucidation by multinuclear NMR spectra, confirms the chelate formation and reveals a trigonal environment for the low coordinated phosphorus, with the P-Mo(0) vector bent out of the benzazaphosphole ring plane by 14.4° (0.57 A?), together with axial chirality of the molecules in the racemic crystals by twisting of the benzazaphosphole and phenyl π-planes around the common C(2)-C(21) bond. The Royal Society of Chemistry 2013.
- Niaz, Basit,Ghalib, Mohammed,Jones, Peter G.,Heinicke, Joachim W.
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p. 9523 - 9532
(2013/08/23)
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- METHOD FOR PRODUCING ALCOHOL COMPOUND
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Disclosed is a practical method for efficiently producing an alcohol compound by hydrogenating an aldehyde by using a homogeneous copper catalyst which is an easily-available low-cost metal species. Specifically disclosed is a method for producing an alcohol compound, which is characterized in that a hydrogenation reaction of an aldehyde compound is performed in the presence of a homogeneous copper catalyst and a diphosphine compound.
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Page/Page column 10-11
(2011/09/14)
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- METHOD FOR PRODUCING ALCOHOL COMPOUND
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Disclosed is a practical method for efficiently producing an alcohol compound by hydrogenating an aldehyde by using a homogeneous copper catalyst which is an easily-available low-cost metal species. Specifically disclosed is a method for producing an alcohol compound, which is characterized in that a hydrogenation reaction of an aldehyde compound is performed in the presence of a homogeneous copper catalyst and a diphosphine compound.
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Page/Page column 14-15
(2011/11/01)
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- Sodium tetraalkoxyborates: Intermediates for the quantitative reduction of aldehydes and ketones to alcohols through ball milling with NaBH4
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Stoichiometric molecular solid-state vibrational ball milling, solvent-free kneading ball milling, and mechanochemical ball milling of varied aldehydes and ketones with unmodified sodium borohydride under temperature control uses all hydrogen atoms of the reducing agent in fast reactions. It provides quantitative yields of thermally stable sodium tetraalkoxyborates. The easily isolated solids are extremely sensitive towards hydrolysis, leading to quantitative yields of the corresponding alcohols. The rapid syntheses are regiospecific and stereoselective. Varied substituents are not attacked, including the bromine of α-bromo ketones. Conjugated aldehydes and ketones provide quantitative yields of the allylic alcohols free of contamination by saturated alcohols that would occur by reaction in solution. Depending on the stoichiometric ratio, benzil is quantitatively reduced to benzoin (4:1 ratio) or dihydrobenzoin (2:1 ratio).
- Naimi-Jamal, M. Reza,Mokhtari, Javad,Dekamin, Mohammad G.,Kaupp, Gerd
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experimental part
p. 3567 - 3572
(2009/10/26)
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- Direct reductive amination of carbonyl compounds with primary/secondary amines using recyclable water-soluble FeII/EDTA complex as catalyst
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Direct reductive amination of aliphatic, aromatic and heterocyclic carbonyl compounds with primary/secondary amines is reported with water-soluble FeII/EDTA complex as a catalyst using low-pressure molecular hydrogen in a biphasic media. The catalyst is highly selective, recyclable and is an excellent replacement for expensive noble metal catalysts or stoichiometric reducing agents.
- Bhor, Malhari D.,Bhanushali, Mayur J.,Nandurkar, Nitin S.,Bhanage, Bhalchandra M.
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p. 965 - 969
(2008/09/17)
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- Silica chromate as an oxidising agent for the chemoselective oxidation of alcohols and the oxidative deprotection of trimethylsilyl ethers
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Silica chromate easily converts primary and secondary alcohols to corresponding carbonyl compounds in the presence of wet SiO2 both in dichloromethane and under solvent-free conditions at room temperature with good to excellent yields. Primary and secondary trimethylsilyl ethers were converted into the corresponding carbonyl compounds or alcohols by using silica chromate and wet SiO2 in dichloromethane at room temperature with good to excellent yields.
- Zolfigol, Mohammad A.,Shirini, Farhad,Mohammadpoor-Baltork, Iraj,Choghamarani, Arash Gh.,Hajjami, Maryam,Sedaghat, Abdol M.
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p. 113 - 116
(2007/10/03)
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- The use of Nafion-H as an efficient catalyst for the deprotection of trimethylsilyl ethers to their corresponding alcohols under mild and heterogeneous conditions
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Trimethylsilyl ethers were converted to their corresponding alcohols in the presence Nafion-H and wet SiO2 with good-to-excellent yields under mild and heterogeneous conditions.
- Zolfigol, Mohammad Ali,Mohammadpoor-Baltork, Iraj,Habibi, Davood,Mirjalili, Bibi Fatemeh,Bamoniri, Abdolhamid
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p. 2189 - 2193
(2007/10/03)
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- Generation of thiols by biotransformation of cysteine-aldehyde conjugates with baker's yeast
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Baker's yeast was shown to catalyze the transformation of cysteine-furfural conjugate into 2-furfurylthiol. The biotransformation's yield and kinetics were influenced by the reaction parameters such as pH, incubation mode (aerobic and anaerobic), and substrate concentration. 2-Furfurylthiol was obtained in an optimal 37% yield when cysteine-furfural conjugate at a 20 mM concentration was anaerobically incubated with whole cell baker's yeast at pH 8.0 and 30 °C. Similarly to 2-furfurylthiol, 5-methyl-2-furfurylthiol (11%), benzylthiol (8%), 2-thiophenemethanethiol (22%), 3-methyl-2-thiophenemethanethiol (3%), and 2-pyrrolemethanethiol (6%) were obtained from the corresponding cysteine-aldehyde conjugates by incubation with baker's yeast. This work indicates the versatile bioconversion capacity of baker's yeast for the generation of thiols from cysteine-aldehyde conjugates. Thanks to its food-grade character, baker's yeast provides a biochemical tool to produce thiols, which can be used as flavorings in foods and beverages.
- Huynh-Ba, Tuong,Matthey-Doret, Walter,Fay, Laurent B.,Rhlid, Rachid Bel
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p. 3629 - 3635
(2007/10/03)
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- Heterocyclic compounds, pharmaceutical compositions comprising same, and methods for inhibiting β-amyloid peptide release and/or its synthesis by use of such compounds
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Disclosed are compounds which inhibit β-amyloid peptide release and/or its synthesis, and, accordingly, have utility in treating Alzheimer's disease. Also disclosed are pharmaceutical compositions comprising a compound which inhibits β-amyloid peptide release and/or its synthesis as well as methods for treating Alzheimer's disease both prophylactically and therapeutically with such pharmaceutical compositions.
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- Cycloalkyl, lactam, lactone and related compounds, pharmaceutical compositions comprising same, and methods for inhibiting beta-amyloid peptide release and/or its synthesis by use of such compounds
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Disclosed are compounds which inhibit β-amyloid peptide release and/or its synthesis, and, accordingly, have utility in treating Alzheimer's disease. Also disclosed are pharmaceutical compositions comprising a compound which inhibits β-amyloid peptide release and/or its synthesis as well as methods for treating Alzheimer's disease both prophylactically and therapeutically with such pharmaceutical compositions.
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- Methods and compounds for inhibiting β-amyloid peptide release and/or its synthesis
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Disclosed are compounds which inhibit β-amyloid peptide release and/or its synthesis, and, accordingly, have utility in treating Alzheimer's disease. Also disclosed pharmaceutical compositions comprising a compound which inhibits β-amyloid peptide release and/or its synthesis as well as methods for treating Alzheimer's disease both prophylactically and therapeutically with such pharmaceutical compositions.
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