- Formal [3+2] Cycloaddition of Nitrosoallenes with Carbonyl and Nitrile Compounds to Form Functional Cyclic Nitrones
-
The synthesis of functional cyclic nitrones via [3+2] cycloadditions of allenamide-derived nitrosoallenes with carbonyl/nitrile compounds, including ketones, esters, and nitriles, is presented herein. Rapid carbon-carbon, carbon-oxygen, and carbon-nitrogen bond formations were achieved with in situ prepared nitrosoallenes, and densely substituted oxacyclic and carbocyclic nitrones containing tetrasubstituted carbon centers were successfully synthesized. The spirocyclic nitrone products synthesized from cyclic dicarbonyl compounds underwent the unique skeletal rearrangements to cyclic α-ketonitrones.
- Tanimoto, Hiroki,Shitaoka, Takashi,Yokoyama, Keiichi,Morimoto, Tsumoru,Nishiyama, Yasuhiro,Kakiuchi, Kiyomi
-
-
Read Online
- Catalyst-Free [3 + 3] Annulation/Oxidation of Cyclic Amidines with Activated Olefins: When the Substrate Olefin Is Also an Oxidant
-
Herein we describe a catalyst-free regioselective [3 + 3] annulation/oxidation reaction of cyclic amidines such as DBU (1,8-diazabicyclo(5.4.0)undec-7-ene) and DBN (1,5-diazabicyclo(4.3.0)non-5-ene) with activated olefins, i.e., 2-arylidenemalononitriles and 2-cyano-3-aryl acrylates, to afford tricyclic 2-pyridones and pyridin-2(1H)-imines, respectively. The mechanism has been proposed based on DFT calculations. In the reaction, the cyclic amidines serve as C,N-bisnucleophiles for the cyclization, while the olefins play a dual role by acting as both reactants and oxidants.
- Han, Wendan,Li, Yuanhang,Raveendra Babu, Kaki,Li, Jing,Tang, Yuhai,Wu, Yong,Xu, Silong
-
supporting information
p. 7832 - 7841
(2021/06/25)
-
- Direct Cyclopropanation of α-Cyano β-Aryl Alkanes by Light-Mediated Single Electron Transfer Between Donor–Acceptor Pairs
-
Cyclopropanes are traditionally prepared by the formal [2+1] addition of carbene or radical based C1 units to alkenes. In contrast, the one-pot intermolecular cyclopropanation of alkanes by redox active C1 units has remained unrealised. Herein, we achieve
- Li, Jing,Lear, Martin J.,Hayashi, Yujiro
-
p. 5901 - 5905
(2021/03/09)
-
- Trideuteromethylation Enabled by a Sulfoxonium Metathesis Reaction
-
A conceptually novel sulfoxonium metathesis reaction between TMSOI and cost-effective DMSO-d6 is developed for the efficient generation of a new trideuteromethylation reagent TDMSOI. The new reagent TDMSOI is produced highly efficiently by simply heating a mixture of TMSOI and DMSO-d6 and directly used for subsequent trideuteromethylation in a "one-pot" operation. The preparative power of the new versatile reagent and the "one-pot" protocol is demonstrated by its use to install the ?CD3 moiety into broad functionalities including phenols, thiophenols, acidic amines, and enolizable methylene units in high yield and at a useful level of deuteration (>87% D).
- Shen, Zuyuan,Zhang, Shilei,Geng, Huihui,Wang, Jiarui,Zhang, Xinyu,Zhou, Anqi,Yao, Cheng,Chen, Xiaobei,Wang, Wei
-
supporting information
p. 448 - 452
(2019/01/14)
-
- Room Temperature, Reductive Alkylation of Activated Methylene Compounds: Carbon-Carbon Bond Formation Driven by the Rhodium-Catalyzed Water-Gas Shift Reaction
-
The rhodium-catalyzed water-gas shift reaction has been demonstrated to drive the reductive alkylation of several classes of activated methylene compounds at room temperature. Under catalysis by rhodium trichloride (2-3 mol %), carbon monoxide (10 bar), water (2-50 equiv), and triethylamine (2.5-7 equiv), the scope has been successfully expanded to cover a wide range of alkylating agents, including aliphatic and aromatic aldehydes, as well as cyclic ketones, in moderate to high yields. This method is comparable to, and for certain aspects, surpasses the established reductive alkylation protocols.
- Denmark, Scott E.,Ibrahim, Malek Y. S.,Ambrosi, Andrea
-
p. 613 - 630
(2017/06/05)
-
- Solvent-free preparation method for substituted cyanoacetate compound
-
The invention discloses a solvent-free preparation method for a substituted cyanoacetate compound. The method is characterized by comprising the following steps: subjecting an aldehyde compound (I) represented by a formula shown in the description, cyanoacetate (II) represented by a formula shown in the description and a dihydropyridine ester (III) represented by a formula shown in the description to a hybrid reaction under solvent-free conditions, and carrying out separation and purification after the reaction is completed, thereby obtaining the substituted cyanoacetate (IV) represented by a formula shown in the description. According to the method, aldehydes, cyanoacetate and dihydropyridine esters serve as raw materials for the first time, and the substituted cyanoacetate can be efficiently synthesized through a one-pot method reaction without solvents and catalysts, so that the preparation method is simple, efficient and environmentally friendly.
- -
-
Paragraph 0027; 0033-0035
(2018/02/04)
-
- A substituted cyano acetate preparation method (by machine translation)
-
The invention discloses a substituted cyano acetate preparation method, characterized in that comprises the following steps: (I) takes the aldehyde class compound, cyano acetic acid esters (II) and (III) dihydro pyridine ester, uses water as solvent, mixe
- -
-
Paragraph 0022-0039
(2017/05/19)
-
- AlCl3 catalyzed coupling of: N-benzylic sulfonamides with 2-substituted cyanoacetates through carbon-nitrogen bond cleavage
-
A new cross-coupling reaction of N-benzylic sulfonamides with 2-substituted cyanoacetates for the synthesis of 2-substituted benzylbenzene was reported. In the presence of AlCl3, a broad range of N-benzylic sulfonamides reacted smoothly with 2-substituted cyanoacetates to afford structurally diverse benzylbenzenes in moderate to excellent yields. The conversion could be enlarged to gram-scale efficiently. The practicability of this approach was further manifested in the synthesis of a related bioactive agent with high anti-inflammatory activity.
- Hu, Chen,Hong, Gang,Qian, Xiaofei,Kim, Kwang Rim,Zhu, Xiaoyan,Wang, Limin
-
supporting information
p. 4984 - 4991
(2017/07/10)
-
- A novel bifunctional Pd-ZIF-8/rGO catalyst with spatially separated active sites for the tandem Knoevenagel condensation-reduction reaction
-
A novel bifunctional catalyst with spatially separated active sites was prepared by the immobilization of Pd nanoparticles (NPs) via covalent interaction and coordination of a zeolitic imidazolate framework (ZIF-8) on the surface of graphene oxide (GO), respectively, which was used as an efficient catalyst for the Knoevenagel condensation-reduction tandem reaction. The results of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Raman spectroscopy, UV-vis spectroscopy, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) demonstrated that Pd and ZIF-8 were successfully immobilized on the surface of GO, and the GO was reduced to reduced graphene oxide (rGO) using NaBH4 as the reductant in the preparation of Pd-ZIF-8/rGO. The textural properties and morphology of Pd-ZIF-8/rGO were characterized by N2 adsorption-desorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Pd-ZIF-8/rGO shows excellent catalytic performance in the tandem reaction with 100% benzaldehyde conversion and 98.3% selectivity to benzylmalononitrile. The excellent catalytic performance of Pd-ZIF-8/rGO in the tandem reaction is due to the high catalytic activities of spatially separated Pd NPs and ZIF-8 active sites and concentrated reactants on the surface of Pd-ZIF-8/rGO due to the π-π interaction between rGO and the reactants. The anchoring and stabilization effects of oxygenated groups of GO inhibit the aggregation and leakage of active sites, leading to good catalytic recyclability with almost unchanged catalytic activity for more than eight cycles in the tandem reaction.
- Wang, Hefang,Wang, Yansu,Jia, Aizhong,Wang, Cunyue,Wu, Luming,Yang, Yongfang,Wang, Yanji
-
p. 5572 - 5584
(2017/12/07)
-
- INHIBITORS OF BACTERIAL GLYCOSYL TRANSFERASES
-
Described herein are compounds of Formula (I'), Formula (IA), Formulae (I)-(VII), pharmaceutically acceptable salts, solvates, hydrates, polymorphs, co-crystals, tautomers, stereoisomers, isotopically labeled derivatives, and prodrug sthereof. The invention also provides pharmaceutical compositions of the compounds for human and veterinary use. Compounds of the present invention are useful for inhibiting bacterial growth and therefore are useful in treating and/or preventing bacterial infections. Methods of using the compounds for treating and/or preventing a bacterial infection in a subject are also described.
- -
-
Paragraph 00727; 00730-00731
(2016/12/22)
-
- Base-Promoted Cascade Approach for the Preparation of Reduced Knoevenagel Adducts Using Hantzsch Esters as Reducing Agent in Water
-
A cascade Knoevenagel condensation-reduction approach, which was carried out in water, has been reported. Using Hantzsch esters as reducing agent, under the promotion of base, a variety of reduced Knoevenagel adducts could be easily prepared by direct alkylation of malononitrile, ethyl 2-cyanoacetate, and 2-(4-nitrophenyl)acetonitrile, respectively. Meanwhile, a gram-scale synthesis of the protocol was also realized with excellent isolated yield.
- He, Tao,Shi, Ronghua,Gong, Yimou,Jiang, Guangyou,Liu, Ming,Qian, Shan,Wang, Zhouyu
-
supporting information
p. 1864 - 1869
(2016/07/16)
-
- Reaction of 3-arylidenepropenoic acid derivatives with triethylamine and other amines; Unexpected reductions and vinylogations
-
Exposure of ethyl 2-cyano-3-(2-methoxy-5-nitrophenyl)acrylate 1f to triethylamine in hot ethanol resulted in the formation of the dihydro derivative 2f and vinylogue 3f in high yields. Single crystal X-ray data are provided for 3f. Similar reactions were observed for various analogues. The reaction was studied changing aryl substituent, amines and solvents. Pyridyl, thienyl analogues were also examined. The study was extended to cyclic molecules incorporating such systems like thiazolidinedione 8, 3-cyanocoumarin 9 and 4-arylidene-isoquinoline-2,4-diones 11. The last group gave vinylogated products, 4-cinnamylidene-isoquinolinediones and 4-hydroxylated species. A few examples of arylidene derivatives from malononitrile, ethyl acetoacetate, acetyl acetone and ethyl methylsufonylacetate were investigated. Ethyl cinnamate and β-nitrostyrene were unaffected. The reaction is considered to be possibly radical mediated, since addition of free radical quencher suppressed the reaction. Contrary to the effects of thermal conditions, irradiation of 1f in ethanol at 254 and 365 nm gave complex mixtures. A few other interesting observations in this study are noted: vinylogation of 1f with acetaldehyde to 3f; formation of 3f from 1f by the treatment with triethylamine, palladium carbon and reduction of 1f to 2f by triethylammonium formate in DMF.
- Harisha, Attimogae Shivamurthy,Nayak, Suresh Parameshwar,Nagarajan, Kuppuswamy,Row, Tayur Narasingarow Guru,Hosamani, Amar A.
-
p. 2880 - 2889
(2016/05/24)
-
- Nano-K2CO3: Preparation, characterization and evaluation of reactive activities
-
A novel base, nano-K2CO3, was easily prepared by ultrafine wet milling. The surface properties and the reactive activities of nano-K2CO3 were characterized. It was found that such a base showed higher basicity than normal K2CO3 and could replace sodium (or potassium) alkoxide to carry out monoalkylation and oximation of active methylene compounds. The nano-K2CO3 could be regenarated and reused 10 times without loss of its reactive activity.
- Li, Jun-Zhang,Fan, Shi-Ming,Sun, Xuan-Fei,Liu, Shouxin
-
p. 1865 - 1869
(2016/01/20)
-
- The organic-synthetic potential of recombinant Ene reductases: Substrate-Scope Evaluation and Process Optimization
-
In this study an evaluation of the synthetic potential of a broad range of recombinant ene reductases was performed. In detail, a library of 23 ene reductases was used to screen the C=C reduction of 21 activated alkenes from different compound classes as substrates. The chosen set of substrates comprises nitroalkenes with an aryl substituent at the β-position and a methyl substituent at the α- or β-position, α,β-unsaturated carboxylic acids and their esters with and without substituents at the β-position, a range of cyclic α,β-unsaturated ketones with different ring sizes and substitution patterns and one α,β-unsaturated boronic acid. After we obtained insight into the substrate scope, several biotransformations were prioritised and further investigated in a screening of 41 reaction parameters (which included chaotropic and kosmotropic salts, polyols, buffer solutions, amino acids and organic solvents) towards their impact on the activity and enantioselectivity of the applied ene reductases. Under the optimised conditions, selected reduction processes were performed on an increased lab scale (up to 30 mL) with up to 10% substrate concentration, which led in general to both high conversion and (if chiral products were formed) enantioselectivity. Comprehensive screening: A detailed screening of 23 recombinant ene reductases for the reduction of 21 activated alkenes is performed as well as a subsequent study of the influence of 41 reaction parameters towards the enzyme activity and selectivity of selected reactions. In addition, a range of biocatalytic reductions on an increased laboratory scale are performed with substrate concentrations between 5 and 100 gL-1. EWG=Electron-withdrawing group.
- Re?, Tina,Hummel, Werner,Hanlon, Steven P.,Iding, Hans,Gr?ger, Harald
-
p. 1302 - 1311
(2015/04/27)
-
- Thiazole formation through a modified Gewald reaction
-
The synthesis of thiazoles and thiophenes starting from nitriles, via a modified Gewald reaction has been studied for a number of different substrates. 1,4-Dithiane-2,5-diol was used as the aldehyde precursor to give either 2-substituted thiazoles or 2-substituted aminothiophenes depending on the substitution of the α-carbon to the cyano group.
- Mallia, Carl J.,Englert, Lukas,Walter, Gary C.,Baxendale, Ian R.
-
supporting information
p. 875 - 883
(2015/08/24)
-
- Novel triethylamine mediated thermal reactions of 3-aryl-2-cyanoprop-2-enoic acid derivatives - Demethylation, reduction and vinylogation
-
3-Aryl-2-propenoic acid derivatives undergo interesting reactions with hot triethylamine. Substrates like 6 having a methoxyl with a nitro in the ortho and cyanoacrylic derivatives in the para positions give O-demethylated products, for example, entacapone 7. On the other hand compounds like 16 having the NO2 in the para and cyanoacrylic in the ortho position undergo reduction and vinylogation. The latter phenomenon is observed in the absence of the NO2 group also.
- Harisha, Attimogae Shivamurthy,Nayak, Suresh Parameshwar,Nagarajan, Kuppuswamy,Guru Row, Tayur Narasingarow,Hosamani, Amar A.
-
p. 1427 - 1431
(2015/03/04)
-
- Catalyst-free chemoselective reduction of the carbon-carbon double bond in conjugated alkenes with Hantzsch esters in water
-
A simple, efficient and green protocol for chemoselective reduction of carbon-carbon double bond in conjugated alkenes with Hantzsch esters is described. Without any additional catalysts, a series of conjugated alkenes with strong electron-withdrawing groups were reduced in water with excellent yield. Functional groups such as nitrile, ester, nitro, fluoro, chloro, bromo, furanyl and benzyl are all tolerated by the reaction conditions employed. The Royal Society of Chemistry.
- He, Qi,Xu, Zhihong,Jiang, Dehong,Ai, Wensi,Shi, Ronghua,Qian, Shan,Wang, Zhouyu
-
p. 8671 - 8674
(2014/03/21)
-
- One-pot multistep cascade reactions over multifunctional nanocomposites with pd nanoparticles supported on amine-modified mesoporous silica
-
Two kinds of multifunctional nanocomposites, SBA-15-NH2/Pd-p and SBA-15-NH2/Pd-f, with platelet-like and fiber-like morphologies, respectively, were fabricated by immobilizing Pd NPs onto amine-functionalized SBA-15. Some of the amino groups acted as anchoring sites for Pd NPs, whilst the remaining groups acted as Bronsted basic sites. As a result, the composites served as excellent multifunctional heterogeneous catalysts for one-pot multistep cascade reaction sequences. Moreover,when diffusion was the rate-determine step, SBA-15-NH2/Pd-p, with small mesopores, was superior to the fiber-like control sample, owing to its short diffusion length, a lower possibility of pore clogging, and better mass transportation for the reaction species during the catalysis.
- Li, Ping,Liu, Hua,Yu, Yu,Cao, Chang-Yan,Song, Wei-Guo
-
p. 2459 - 2465
(2013/10/08)
-
- Overturning established chemoselectivities: Selective reduction of arenes over malonates and cyanoacetates by photoactivated organic electron donors
-
The prevalence of metal-based reducing reagents, including metals, metal complexes, and metal salts, has produced an empirical order of reactivity that governs our approach to chemical synthesis. However, this reactivity may be influenced by stabilization of transition states, intermediates, and products through substrate-metal bonding. This article reports that in the absence of such stabilizing interactions, established chemoselectivities can be overthrown. Thus, photoactivation of the recently developed neutral organic superelectron donor 5 selectively reduces alkyl-substituted benzene rings in the presence of activated esters and nitriles, in direct contrast to metal-based reductions, opening a new perspective on reactivity. The altered outcomes arising from the organic electron donors are attributed to selective interactions between the neutral organic donors and the arene rings of the substrates.
- Doni, Eswararao,Mondal, Bhaskar,O'Sullivan, Steven,Tuttle, Tell,Murphy, John A.
-
p. 10934 - 10937
(2013/08/23)
-
- HETEROCYCLIC COMPOUNDS FOR THE INHIBITION OF PASK
-
Disclosed herein are new heterocyclic compounds and compositions and their application as pharmaceuticals for the treatment of disease. Methods of inhibiting PAS Kinase (PASK) activity in a human or animal subject are also provided for the treatment of diseases such as diabetes mellitus.
- -
-
Page/Page column 56
(2012/11/08)
-
- Construction of 1,2,5-tricarbonyl compounds using methyl cyanoacetate as a glyoxylate anion synthon combined with copper(I) iodide-catalyzed aerobic oxidation
-
A practical and efficient synthesis of various 1,2,5-tricarbonyl compounds is described. The synthesis has been carried out by a conjugate addition of methyl cyanoacetate to the β-position of α,β-unsaturated carbonyl compounds and a subsequent copper(I) iodide-catalyzed aerobic oxidation. In addition, various α-aryl- and α-alkyl-α-keto esters have been synthesized using a similar approach. Copyright
- Kim, Se Hee,Kim, Ko Hoon,Kim, Jae Nyoung
-
supporting information; experimental part
p. 3335 - 3339
(2012/01/19)
-
- Tandem reactions of 1,2-allenic ketones leading to substituted benzenes and α,β-unsaturated nitriles
-
One-pot double Michael addition/intramolecular aldol reaction/ decarboxylation of 1,2-allenic ketones with cyanoacetate offers an efficient and convenient approach to highly functionalized benzenes. With 2-substituted cyanoacetates, the reaction proceeds via a different tandem process to afford α,β-unsaturated nitriles effectively.
- Zhang, Xinying,Jia, Xuefei,Fang, Liangliang,Liu, Nan,Wang, Jianji,Fan, Xuesen
-
supporting information; experimental part
p. 5024 - 5027
(2011/11/12)
-
- Palladium-supported ionic liquid catalyst (Pd-SH-SILC) immobilized on mercaptopropyl silica gel as a chemoselective, reusable and heterogeneous catalyst for catalytic hydrogenation
-
Palladium acetate was immobilized as Pd-SH-SILC (Pd-supported ionic liquid catalyst) in the pores of amorphous mercaptopropyl silica gel with the aid of an ionic liquid [bmim]BF4. The heterogeneous Pd-SH-SILC was effective for catalytic hydrogenation of a variety of olefins at atmospheric pressure and room temperature. It withstood recycling up to 10 times by decantation.
- Hagiwara, Hisahiro,Nakamura, Tomomi,Hoshi, Takashi,Suzuki, Toshio
-
scheme or table
p. 1133 - 1137
(2011/06/26)
-
- One-pot approach for C-C bond formation through ruthenium-amido complex catalyzed tandem aldol reaction/hydrogenation
-
A one-pot novel and efficient approach was developed for the -alkylation of various nitriles with carbonyl compounds using ruthenium-amido complex catalyst 1. The C-C bond was formed through aldol reaction followed by hydrogenation with triethylamine-formic acid (TEAF) and 1. Moderate to high yields were obtained, and a variety of functional groups were tolerated, including nitro and chloro groups, and a furan ring. Georg Thieme Verlag Stuttgart New York.
- Sun, Haifeng,Ye, Deju,Jiang, Hualiang,Chen, Kaixian,Liu, Hong
-
supporting information; experimental part
p. 2577 - 2582
(2010/09/05)
-
- Ethynyl-1,2-benziodoxol-3(1H)-one (EBX): An exceptional reagent for the ethynylation of keto, cyano, and nitro esters
-
Hot alkyne! The in situ generation of ethynyl-1,2-benziodoxol-3(1H)-one (EBX) from a silyl-protected reagent by using TBAF is reported. EBX displayed exceptional acetylene transfer ability onto stabilized enolates (see scheme), even at -78 □°C. The mild reaction conditions allowed the first ethynylation reactions of linear keto, cyano, and nitro esters in high yields to give all-carbon quaternary centers or non-natural amino acids after selective reduction of the nitro group.
- Gonzalez, Davinia Fernandez,Brand, Jonathan P.,Waser, Jerome
-
supporting information; experimental part
p. 9457 - 9461
(2010/10/03)
-
- Polymer-supported hantzsch 1,4-dihydropyridine ester: An efficient biomimetic hydrogen source for the reduction of ketimines and electron-withdrawing group conjugated olefins
-
A polymer-supported Hantzsch 1,4-dihydropyridine ester was observed to be a useful selective reducing agent for the reduction of ketimines and electron-withdrawing conjugated olefins. The rate of the reduction of electron-withdrawing conjugated olefins is dependent on the nature of the conjugated substituents and could be enhanced by microwave irradiation. The reduction of (Z)-α-cyano-β-bromomethylcinnamates to cyclopropane derivatives using polymer-supported Hantzsch 1,4-dihydropyridine ester was found to proceed stereoselectively and in good yields.
- Che, Jun,Lam, Yulin
-
experimental part
p. 1752 - 1758
(2010/09/11)
-
- Cobalt(II) chloride hexahydrate-diisopropylamine catalyzed mild and chemoselective reduction of carboxylic esters with sodium borohydride
-
The cobalt-catalyzed reduction of unsaturated α-cyano carboxylic esters using sodium borohydride (NaBH4) leads to the corresponding saturated cyano alcohols in high yields. In particular, the new catalytic system cobalt(II) chloride-diisopropylamine in combination with NaBH4 showed excellent activity in the chemoselective reduction of a variety of carboxylic esters to their corresponding alcohols in good to excellent yields under mild conditions. Georg Thieme Verlag Stuttgart.
- Jagdale, Arun R.,Paraskar, Abhimanyu S.,Sudalai, Arumugam
-
experimental part
p. 660 - 664
(2009/07/03)
-
- Development of pharmaceutical drugs, drug intermediates and ingredients by using direct organo-click reactions
-
Here we report on our studies of the use of combinations of amino acids, amines, K2CO3 or Cs2CO3 and CuSO4/Cu for catalysing green cascade reactions. We aimed to prepare the highly reactive and substituted olefin species 7 and 8, under very mild and environmentally friendly conditions, thus giving the hydrogenated products 10 and 12 through the action of Hantzsch ester (4) by self-catalysis through decreasing the HOMO-LUMO energy gaps between olefins 7/8 and Hantzsch ester (4) through biomimetic reductions. Highly useful compounds 10 to 14 were assembled from simple substrates such as aldehydes 1, ketones 2, CH acids 3, Hantzsch ester (4) and alkyl halides 5 by diversity-oriented green synthesis involving cascade olefination/hydrogenation (O/H), olefination/hydrogenation/alkylation (O/H/A) and hydrogenation/olefination/hydrogenation (H/O/H) reaction sequences in one-pot fashion with stereospecific organo- and organo-/metal-carbonate catalysis. Highly functionalized diverse compounds such as 10 to 14 are biologically active products and have found wide applications as pharmaceutical drugs, drug intermediates and drug ingredients. For the first time in organocatalysis, we report the O/H/A/TE reaction to furnish high yields of transesterification products 11 by simply mixing the reactants under proline/K2CO3 catalysis conditions. Additionally, a novel organocatalytic H/O/H reaction sequence for the synthesis of alkyl-substituted aromatics has been developed. Furthermore, for the first time we have developed organocatalysed cascade olefination/hydrogenation/hydrolysis (O/H/H) reactions to furnish highly useful materials such as 2-oxochroman-3-carboxylic acid (14kc) and 2-amino-4H-chromene-3-carbonitrile (14kj) in good yields. Experimentally simple and environmentally friendly organocatalytic two-carbon homologation through cascade O/H/H reactions of aldehydes 1, Meldrum's acid (3c), Hantzsch ester (4) and acetic acid/triethylamine in ethanol has been demonstrated. Additionally, we have developed a green synthesis of the highly substituted 1,2,3-triazole 17 from simple substrates through a two-step combination of olefination/hydrogenation/alkylation and Huisgen cycloaddition reaction sequences under stereospecific organocopper catalysis conditions. In this paper we have found strong support for our hypothesis that, "decreasing the HOMO-LUMO energy gap between olefins 7/8 and Hantzsch ester (4) will drive the biomimetic hydrogenation reaction by self-catalysis". This self-catalysis was further confirmed with many varieties of examples. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Ramachary, Dhevalapally B.,Kishor, Mamillapalli,Reddy, Y. Vijayendar
-
supporting information; experimental part
p. 975 - 993
(2009/04/11)
-
- 3-Butyl-1-methylimidazolinium borohydride ([bmim][BH4])-a novel reducing agent for the selective reduction of carbon-carbon double bonds in activated conjugated alkenes
-
A novel ionic reducing reagent, 3-butyl-1-methylimidazolium borohydride ([bmim][BH4]), was synthesized and successfully used for the selective reduction of carbon-carbon double bonds in conjugated alkenes as well as the α,β-carbon-carbon double bonds in highly activated α,β,γ,δ-unsaturated alkenes. The reagent can be regenerated and reused several times without losing its activity.
- Wang, Jiayi,Song, Gonghua,Peng, Yanqing,Zhu, Yidong
-
supporting information; scheme or table
p. 6518 - 6520
(2009/04/06)
-
- Unprecedented reaction between ethyl α-cyanocinnamate and o-phenylenediamine: Development of an efficient method for the transfer hydrogenation of electronically depleted olefins
-
A reaction between ethyl α-cyanocinnamate and o-phenylenediamine under thermal conditions yielded 2-cyano-3-phenyl-propionic acid ethyl ester, 2-phenyl benzimidazole, and ethyl cyanoacetate. The mechanistic revelations led to the development of a simple and efficient transfer-hydrogenation process from the in situ generated benzimidazolines to activated olefins under solventless and catalyst-free conditions. Georg Thieme Verlag Stuttgart.
- Kumar, Satish,Kapoor, Kamal K.
-
p. 2809 - 2814
(2008/02/13)
-
- Ruthenium catalysed reduction of alkenes using sodium borohydride
-
The reduction of alkenes has been achieved using NaBH4 as the reducing agent using 0.5-1.0 mol % Ru(PPh3)4H2 in the presence of water.
- Adair, Gareth R.A.,Kapoor, Kamal K.,Scolan, Alexandre L.B.,Williams, Jonathan M.J.
-
p. 8943 - 8944
(2007/10/03)
-
- Environmentally friendly one-pot synthesis of α-alkylated nitriles using hydrotalcite-supported metal species as multifunctional solid catalysts
-
A ruthenium-grafted hydrotalcite (Ru/HT) and hydrotalcite-supported palladium nanoparticles (Pdnano/ HT) are easily prepared by treating basic layered double hydroxide, hydrotalcite (HT, Mg6Al 2(OH)16CO3) with aqueous RuCl 3·n H2O and K2[PdCl4] solutions, respectively, using surface impregnation methods. Analysis by means of X-ray diffraction, and energydispersive X-ray, electron paramagnetic resonance, and X-ray absorption fine structure spectroscopies proves that a monomeric RuIV species is grafted onto the surface of the HT. Meanwhile, after reduction of a surface-isolated PdII species, highly dispersed Pd nanoclusters with a mean diameter of about 70 A is observed on the Pdnano/HT surface by transmission electron microscopy analysis. These hydrotalcite-supported metal catalysts can effectively promote α-alkylation reactions of various nitriles with primary alcohols or carbonyl compounds through tandem reactions consisting of metal-catalyzed oxidation and reduction, and an aldol reaction promoted by the base sites of the HT. In these catalytic α-alkylations, homogeneous bases are unnecessary and the only by-product is water. Additionally, these catalyst systems are applicable to one-pot syntheses of glutaronitrile derivatives.
- Motokura, Ken,Fujita, Noriaki,Mori, Kohsuke,Mizugaki, Tomoo,Ebitani, Kohki,Jitsukawa, Koichiro,Kaneda, Kiyotomi
-
p. 8228 - 8239
(2007/10/03)
-
- Towards organo-click reactions: Development of pharmaceutical ingredients by using direct organocatalytic bio-mimetic reductions
-
Economic and environmentally friendly bio-mimetic one-pot three and four-component Knoevenagel-hydrogenation (K-H), five-component Knoevenagel-hydrogenation-alkylation (K-H-A) and six-component Knoevenagel-hydrogenation-alkylation-Huisgen cycloaddition (K-H-A-HC) reactions of aldehydes, CH-acids, o-phenylenediamine, alkyl halides and azides using proline, proline-metal carbonate and proline-metal carbonate-Cu I-catalysis, respectively have been developed. Many of K-H and K-H-A compounds have direct application in pharmaceutical chemistry. The Royal Society of Chemistry.
- Ramachary, Dhevalapally B.,Reddy, G. Babul
-
p. 4463 - 4468
(2008/09/19)
-
- A novel and green protocol for two-carbon homologation: A direct amino acid/K2CO3-catalyzed four-component reaction of aldehydes, active methylenes, Hantzsch esters and alkyl halides
-
A novel and green approach for the two-carbon homologation of aldehydes using amino acid catalysis has been developed and further extended to the generation of pharmaceutically active cyano-esters via four-component reactions in one-pot.
- Ramachary, Dhevalapally B.,Kishor,Ramakumar
-
p. 651 - 656
(2007/10/03)
-
- C-C Bond formation from alcohols using a Xantphos ruthenium complex
-
A ruthenium complex of Xantphos has been shown to be a good catalyst for the alkylation of active methylene compounds with a range of alcohols.
- Slatford, Paul A.,Whittlesey, Michael K.,Williams, Jonathan M.J.
-
p. 6787 - 6789
(2007/10/03)
-
- Reactions of acetylenic acid esters with piperazine derivatives
-
Hg(II)-EDTA-dehydrogenation of benzylpiperazine (5) in 50% ethanol with addition of diethyl acetylenedicarboxylate (2) to a minor extent gives rise to (piperazine-1,4-diyl)-bis(maleate) (9), which is inert to Hg(II)-EDTA and results in quantitative yield when Hg(II)-EDTA is omitted. 4-Benzylpiperazin-1- yl)-monomaleate (8) reacts with 2 in various solvents by addition of water with dealkylation and formation of 9. CH-acidic compounds may also be used as proton donors. Analogous reactions, although with minor yields, occur with the propiolates 11 and 12. 1-Substituted piperazines with benzyl, methine or allylic groups (5-5c, 27d-g, and 27h) react readily with acetylenedicarboxylic acid esters to give compounds of type 9, whereas benzhydryl, aromatic and most of the unbranched aliphatic substituents are not replaced. The reactivity of 1,4-disubstituted piperazines corresponds largely to the behaviour of the substituents in the monosubstituted derivatives.
- M?hrle, Hans,Azodi, Katja
-
p. 1021 - 1034
(2008/09/16)
-
- A facile experimental method to determine the hydride affinity of polarized olefins in acetonitrile
-
(Chemical Equation Presented) Choosing a suitable hydride reducing agent and thermodynamic analysis of reduction mechanisms is facilitated by experimental hydride affinities ΔHH-A, which are reported herein for 28 polarized olefins 1 in acetonitrile (see scheme). The method should also be applicable to ketones, aldehydes, and imines.
- Zhu, Xiao-Qing,Zhang, Min,Liu, Qiao-Yun,Wang, Xiao-Xiao,Zhang, Jian-Yu,Cheng, Jin-Pei
-
p. 3954 - 3957
(2007/10/03)
-
- Transfer hydrogenation of activated C=C bonds catalyzed by ruthenium amido complexes: Reaction scope, limitation, and enantioselectivity
-
(Chemical Equation Presented) It was found that the chemoselectivity could be completely switched from C=O to C=C bonds in the transfer hydrogenation of activated α,β-unsaturated ketones catalyzed by diamine-ruthenium complex. Moreover, this addition via metal hydride had been applied to the reduction of various activated olefins. The electron-withdrawing ability of functional groups substituted on C=C bonds at the α- or β-position had strong influence on the reactivity. In addition, a wide variety of chiral diamine-Ru(II)-(arene) systems was investigated to explore the asymmetric transfer hydrogenation of prochiral α,α-dicyanoolefins. Two parameters had been systematically studied, (i) the structure of the N-sulfonylated chiral diamine ligands, in which several chiral diamines substituted on the benzene ring of DPEN were first reported, and (ii) the structure of the metal precursors, and high enantioselectivitiy (up to 89% ee) at the β-carbon was obtained.
- Xue, Dong,Chen, Ying-Chun,Cui, Xin,Wang, Qi-Wei,Zhu, Jin,Deng, Jin-Gen
-
p. 3584 - 3591
(2007/10/03)
-
- Co-immobilized formate anion and palladium on a polymer surface: A novel heterogeneous combination for transfer hydrogenation
-
A novel heterogeneous combination of a formate reagent and palladium catalyst co-immobilized on a resin support has been developed and shown to be highly efficient and recyclable for transfer hydrogenation of alkenes, imines, nitroarenes and 1,2-dicarbonyl compounds.
- Basu, Basudeb,Das, Sajal,Das, Pralay,Nanda, Ashish K.
-
p. 8591 - 8593
(2007/10/03)
-
- One-pot synthesis of α-alkylated nitriles with carbonyl compounds through consecutive aldol reaction/hydrogenation using a hydrotalcite-supported palladium nanoparticle as a multifunctional heterogeneous catalyst
-
α-Alkylation of various nitriles with carbonyl compounds successfully proceeded using a hydrotalcite-supported palladium nanoparticle as a multifunctional catalyst. The alkylated nitriles were formed through aldol reaction at base sites on the hydrotalcite surface followed by hydrogenation by molecular hydrogen on the palladium nanoparticle.
- Motokura, Ken,Fujita, Noriaki,Mori, Kohsuke,Mizugaki, Tomoo,Ebitani, Kohki,Kaneda, Kiyotomi
-
p. 5507 - 5510
(2007/10/03)
-
- Tandem catalytic condensation and hydrogenation processes in ionic liquids
-
A domino reaction composed of a Knoevenagel condensation combined with a simultaneous catalytic hydrogenation is reported in an ionic liquid solvent under mild conditions (298-363 K and 300 kPa). No interference between the catalysts (Pd/C and amine acetate salt) of the two diverse steps was monitored. The product could be neatly extracted by diethyl ether and the solvent containing the catalysts could be recycled and reused five times without any loss in activity or selectivity. The same methodology in a common organic solvent such as DMA resulted in significant competing parallel hydrogenation of the aldehyde to alcohol.
- Baidossi, Mubeen,Joshi, Asutosh V.,Mukhopadhyay, Sudip,Sasson, Yoel
-
p. 1885 - 1887
(2007/10/03)
-
- New P∧O ligand grafted on periodically organised mesoporous silicas for one-pot bifunctionnal catalysis: Coupling of base catalysed Knoevenagel condensation with in situ Rh catalysed hydrogenation
-
The 1-phosphanorbornadiene-rhodium complex (Rh-PNBD) anchored on a mesostructured porous silica matrix is the first example of a rhodium center chelated by a phosphorus and an oxygen atom belonging to the anchoring siloxane moiety. These new hybrid silicas behave as very active recyclable hydrogenation catalysts, which combined with additional grafted amino functions allow efficiently driven one-pot bifunctionnal catalysis.
- Goettmann, Frederic,Grosso, David,Mercier, Francois,Mathey, Francois,Sanchez, Clement
-
p. 1240 - 1241
(2007/10/03)
-
- Palladium mediated chemoselective reduction of α,β-unsaturated cyano esters with potassium formate
-
A number of α,Β-unsaturated cyano esters have been chemoselectively reduced with potassium formate as hydrogen donor, and palladium(II) acetate as homogeneous catalyst, in DMF without any concomitant reduction of cyano or carboxylate or halogen groups.
- Basu, Basudeb,Bhuiyan, Md. Mosharef Hossain,Jha, Satadru
-
p. 291 - 296
(2007/10/03)
-
- Reduction of activated conjugated alkenes by the InCl3-NaBH 4 reagent system
-
A combination of a catalytic amount of indium (III) chloride and sodium borohydride in acetonitrile reduces selectively the carbon-carbon double bonds in conjugated alkenes such as α,α-dicyano olefins, α,β-unsaturated nitriles, cyanoesters, cyanophosphonate and dicarboxylic esters. However, reduction of chalcones is little different. They are reduced to a mixture of saturated ketones and alcohols if the reaction mixture is quenched with H2O, whereas quenching with MeOH leads to saturated alcohols only.
- Ranu, Brindaban C.,Samanta, Sampak
-
p. 7901 - 7906
(2007/10/03)
-
- Catalytic transfer reduction of conjugated alkenes and an imine using polymer-supported formates
-
An efficient and mild method for catalytic transfer hydrogenation of C=C and C=N double bonds with the aid of resin-supported formate (PSF) as the hydrogen donor and palladium acetate as the catalyst is reported.
- Basu, Basudeb,Bhuiyan, Md. Mosharef H.,Das, Pralay,Hossain, Ismail
-
p. 8931 - 8934
(2007/10/03)
-
- Polysiloxane-supported NAD(P)H model 1-benzyl-1,4-dihydronicotinamide: Synthesis and application in the reduction of activated olefins
-
A new polysiloxane-supported NAD(P)H model, 1-benzyl-1,4-dihydronicotinamide, was designed and synthesized, which can efficiently reduce many activated olefins under mild conditions. The most advantageous features of this new polysiloxane-supported reductant are (i) easy workup and separation of the reaction products and (ii) good potential for recycling use of the reductant, which makes this new polysiloxane-supported NAD(P)H model a promising alternative both in research laboratories and in industrial processes.
- Zhang, Baolian,Zhu, Xiao-Qing,Lu, Jin-Yong,He, Jiaqi,Wang, Peng G.,Cheng, Jin-Pei
-
p. 3295 - 3298
(2007/10/03)
-
- Synthetic and Theoretical Studies on the Reduction of Electron Withdrawing Group Conjugated Olefins Using the Hantzsch 1,4-Dihydropyridine Ester
-
The Hantzsch 1,4-dihydropyridine ester (1) has been observed to be a useful selective reducing agent for the reduction of electron-withdrawing conjugated double bonds. The rate of this reaction was observed to be dependent upon the nature of the conjugate
- Garden, Simon J.,Werneck Guimaraes, Cristiano Ruch,Correa, Marilza B.,Fernandes de Oliveira, Cesar Augusto,Da Cunha Pinto, Angelo,Bicca de Alencastro, Ricardo
-
p. 8815 - 8822
(2007/10/03)
-
- Use of indium hydride (Cl2InH) for chemoselective reduction of the carbon-carbon double bond in conjugated alkenes
-
Indium hydride (Cl2InH) generated in situ from a combination of a catalytic amount of indium(III) chloride and sodium borohydride selectively reduces the carbon-carbon double bond in conjugated alkenes such as α,α-dicyano olefins, α,β-unsaturated nitriles, cyano esters, cyanophosphonate, diesters and ketones.
- Ranu, Brindaban C.,Samanta, Sampak
-
p. 7405 - 7407
(2007/10/03)
-
- Mg-promoted regioselective carbon-silylation of α-phosphorylacrylate derivatives
-
Treatment of aromatic α-phosphorylacrylate derivatives 1a-h with Mg turnings in the presence of trimethylsilyl chloride brought about facile and regioselective C-silylation to give the corresponding β-silylated phosphonates 2a-h in excellent yields. The r
- Kyoda, Makoto,Yokoyama, Takamichi,Kuwahara, Takeshi,Maekawa, Hirofumi,Nishiguchi, Ikuzo
-
p. 228 - 229
(2007/10/03)
-
- A detailed investigation into the oxidation mechanism in Hantzsch 1,4-dihydropyridines by ethyl a-cyanocinnamates and benzylidenemalononitriles
-
A mechanism for the oxidation of Hantzsch 1,4-dihydropyridine (HEH) by substituted ethyl a-cyanocinnamates (1) and benzylidenemalononitriles (2) has been critically investigated. Replacement of HEH by HEH-4,4-d2 and HEH-N-d gave the observed kinetic isotope effects (KIE) of 5.3-6.0 and 1.2-1.3 for the reactions with 1 and 2, respectively, which suggests C4-H bond dissociation is involved in the rate-limiting step and that the N-H bond dissociation is a non-rate-limiting step. The positive ρ values of 1.78 and 1.67 for the reactions of HEH with 1 and 2, respectively, clearly demonstrate the electrophilic nature of the substrates in the transition state (TS) and so indicate that the hydrogen lost from HEH must be a hydride-like species. Correlation analyses on the kinetics, KIE's and activation parameters showed excellent linear dependence on the electronic properties of remote substituents and added further credence to the proposed one-step hydride transfer mechanism. Detailed investigation of the activation parameters not only confirmed the direct HT- mechanism, but also revealed experimentally, for the first time, an entropy-controlled compact TS for the HEH-modeled NAD(P)H oxidations.
- Zhu, Xiao-Qing,Zou, Hong-Ling,Yuan, Ping-Wei,Cao, Lei,Cheng, Jin-Pei
-
p. 1857 - 1861
(2007/10/03)
-