- Nickel/Cobalt-Catalyzed Reductive Hydrocyanation of Alkynes with Formamide as the Cyano Source, Dehydrant, Reductant, and Solvent
-
A Ni/Co co-catalyzed reductive hydrocyanation of various alkynes was developed for the production of saturated nitriles. Hydrocyanic acid is generated in situ from safe and readily available formamide. Formamide played multiple roles as a cyano source, dehydrant, and reductant for the NiII pre-catalyst and vinyl nitriles, along with acting as the co-solvent in this reaction. Detailed mechanistic investigation supported a pathway via hydrocyanation of C≡C bond and the subsequent reduction of C=C bond. Wide substrate scope, the employment of a cheap and stable nickel salt as pre-catalyst, a safe cyano source and convenient experimental operation render this hydrocyanation practical for the laboratory synthesis of saturated nitriles. (Figure presented.).
- Zhang, Jin,Luo, Cui-Ping,Yang, Luo
-
p. 283 - 288
(2020/12/01)
-
- α-Alkylation of arylacetonitriles with primary alcohols catalyzed by backbone modified N-heterocyclic carbene iridium(i) complexes
-
A series of backbone-modified N-heterocyclic carbene (NHC) complexes of iridium(i) (1d-f) have been synthesized and characterized. The electronic properties of the NHC ligands have been assessed by comparison of the IR carbonyl stretching frequencies of thein situprepared [IrCl(CO)2(NHC)] complexes in CH2Cl2. These new complexes (1d-f), together with previously prepared1a-c, were applied as catalysts for the α-alkylation of arylacetonitriles with an equimolar amount of primary alcohols or 2-aminobenzyl alcohol. The catalytic activities of these complexes could be controlled by modifying the N-substituents and backbone of the NHC ligands. The NHC-IrIcomplex1fbearing 4-methoxybenzyl substituents on the N-atoms and 4-methoxyphenyl groups at the 4,5-positions of imidazole exhibited the highest catalytic activity in the α-alkylation of arylacetonitriles with primary alcohols. Various α-alkylated nitriles and aminoquinolines were obtained in high yields through a borrowing hydrogen pathway by using 0.1 mol%1fand a catalytic amount of KOH (5 mol%) under an air atmosphere within significantly short reaction times.
- Arslan, Burcu,Gülcemal, Süleyman
-
p. 1788 - 1796
(2021/02/16)
-
- Base-controlled chemoselectivity: direct coupling of alcohols and acetonitriles to synthesise α-alkylated arylacetonitriles or acetamides
-
We achieved chemoselective synthesis of α-alkylated arylacetonitriles and acetamides by combining Ir complex-catalysed direct coupling of alcohols and nitriles by a simple adjustment of the base. Methanol and ethanol performed well as the alkylating reagents. This method of acetonitrile alkylation provided a novel approach for carbon chain extension.
- Bai, Liang,Ge, Min-Tong,Li, Chen,Qiu, Yuan-Rui,Wang, Ying,Xia, Ai-Bao,Xu, Dan-Qian
-
p. 15200 - 15204
(2021/09/06)
-
- Switchable Cobalt-Catalyzed α-Olefination and α-Alkylation of Nitriles with Primary Alcohols
-
The first switchable α-olefination and α-alkylation of nitriles with primary alcohols catalyzed by a well-defined base transition-metal Co complex was presented. A broad variety of nitriles and primary alcohols are selectively and efficiently converted to the corresponding products by this method. It is noteworthy that the transformation is environmentally benign and atom efficient with H2and H2O being the sole byproducts.
- Paudel, Keshav,Xu, Shi,Ding, Keying
-
supporting information
p. 5028 - 5032
(2021/07/19)
-
- Tandem Acceptorless Dehydrogenative Coupling-Decyanation under Nickel Catalysis
-
The development of new catalytic processes based on abundantly available starting materials by cheap metals is always a fascinating task and marks an important transition in the chemical industry. Herein, a nickel-catalyzed acceptorless dehydrogenative coupling of alcohols with nitriles followed by decyanation of nitriles to access diversely substituted olefins is reported. This unprecedented C=C bond-forming methodology takes place in a tandem manner with the formation of formamide as a sole byproduct. The significant advantages of this strategy are the low-cost nickel catalyst, good functional group compatibility (ether, thioether, halo, cyano, ester, amino, N/O/S heterocycles; 43 examples), synthetic convenience, and high reaction selectivity and efficiency.
- Babu, Reshma,Balaraman, Ekambaram,Midya, Siba P.,Subaramanian, Murugan,Yadav, Vinita
-
supporting information
p. 7552 - 7562
(2021/06/28)
-
- Ru(II)-PBTNNXN complex bearing functional 2-(pyridin-2-yl)benzo[d]thiazole ligand catalyzed α-alkylation of nitriles with alcohols
-
Six tridentate NNN ligand precursors derived from 2-(pyridin-2-yl)benzo[d]thiazole(PBT) with different linkers, PBTNNXN (X = NH, NMe, O, S) (1a–1f), have been successfully prepared. The electronic properties of PBTNNXN ligands are well tunable by differing linkers between PBT skeleton and the pyridine ring, and/or by introducing electron-donating/withdrawing groups on the pyridine ring (R = OMe or F). The ligand precursors and representative complexes Ru (PBTNNNHN)Cl2(PPh3) (2a), Ru (PBTNNNMeN)Cl2(PPh3) (2b), and Ru (PBTNNSN)Cl2(PPh3) (2f) have been characterized by NMR spectroscopy, high-resolution mass spectroscopy, and Fourier transform infrared (FT-IR). The molecular structures of 1f, 2a, and 2f have been determined by X-ray diffraction study. The results indicate that PBTNNNHN ligand in the complex presented coplanar with two five-membered chelating rings. It should be noted that 2a featuring a NH group exhibits superior performance compared to those with other linkers (such as NMe, O, or S). A variety of heterocyclic and aromatic nitriles with aromatic and aliphatic alcohols have been explored in α-alkylation for good to excellent yields. Based on kinetic experiments and mechanistic studies, a proposed mechanism was put forward. Ru-H species and benzaldehyde, which was oxidized from benzyl alcohol, were detected in the catalytic cycle.
- Huang, Shuang,Hong, Xi,Sun, Yong,Cui, He-Zhen,Zhou, Quan,Lin, Yue-Jian,Hou, Xiu-Feng
-
-
- Polysubstituted ethylene compound as well as preparation method and application thereof
-
The invention discloses a polysubstituted ethylene compound as well as a preparation method and application thereof. The invention particularly discloses a preparation method of a polysubstituted ethylene compound as shown in a formula III, which comprises the following step: in an organic solvent, carrying out reaction as shown in the specification on a compound as shown in a formula I and a compound as shown in a formula II in the presence of a palladium catalyst, a phosphine ligand and alkali to obtain the polysubstituted ethylene compound as shown in the formula III. The preparation methodcan be suitable for various types of substrates, and the configuration of double bonds is controllable.
- -
-
Paragraph 0125-0129; 0225-0229
(2020/12/30)
-
- α-Alkylation of Nitriles with Primary Alcohols by a Well-Defined Molecular Cobalt Catalyst
-
The α-alkylation of nitriles with primary alcohols to selectively synthesize nitriles by a well-defined molecular homogeneous cobalt catalyst is presented. Thirty-two examples with up to 95% yield are reported. Remarkably, this transformation is environmentally friendly and atom economical with water as the only byproduct.
- Paudel, Keshav,Xu, Shi,Ding, Keying
-
p. 14980 - 14988
(2020/12/02)
-
- COMPOUNDS THAT INTERACT WITH THE RAS SUPERFAMILY FOR THE TREATMENT OF CANCERS, INFLAMMATORY DISEASES, RASOPATHIES, AND F1BROTIC DISEASE
-
Provided herein are methods and compositions for treating cancers, inflammatory diseases, rasopathies, and fibrotic disease involving aberrant Ras superfamily signaling through the binding of compounds to the GTP binding domain of Ras superfamily proteins including, in certain cases, K-Ras and mutants thereof, and a method for assaying such compositions.
- -
-
Paragraph 0687
(2020/07/14)
-
- Preparation method for acrylonitrile compound taking formamide as cyanogen source
-
The invention discloses a preparation method for an acrylonitrile compound. The preparation method comprises the steps of taking formamide as a cyanogen source and triggering hydrocyanation reaction of formamide and various alkynes under the action of a nickel catalyst, thereby generating the acrylonitrile compound. Reaction temperature is at 100-160 DEG C and reaction time is 6-24 hours. The method can overcome the defects of the traditional method for preparing acrylonitrile compound by using alkyne that operation steps are complex and virulent cyanogen source needs to be used as a reactionraw material. According to the method, simple, low-cost, green and nontoxic formamide is used as the cyanogen source, other dewatering agents (such as phosphorus pentoxide and phosphorus oxychloride)need not be additionally added and the acrylonitrile compound is generated through one-pot reaction; the method is simple in reaction condition, easy in operation, economical and high-efficient; the method shows excellent substrate universality; the acrylonitrile compound is insensitive to air, water and light; yield is high; products can be simply separated and purified; the preparation method has a bright application prospect.
- -
-
Paragraph 0015; 0088
(2019/04/10)
-
- Ni-Mediated Generation of "cN" Unit from Formamide and Its Catalysis in the Cyanation Reactions
-
The in situ generation of a "cyano" unit from readily available organic precursors is of high interest in synthetic chemistry. Herein, we report the first example of Ni-mediated dehydration of formamide to form "CN" and its subsequent catalytic applications in the hydrocyanation of alkynes and cyanation of aryl halides. Formamide can serve as a convenient source for the nitrile unit, in that it releases water as the only byproduct.
- Yang, Luo,Liu, Yu-Ting,Park, Yoonsu,Park, Sung-Woo,Chang, Sukbok
-
p. 3360 - 3365
(2019/03/26)
-
- Method for preparing alkenyl cyanide compounds
-
The invention discloses a method for preparing alkenyl cyanide compounds represented by formula II. Alkynes represented by formula I and a cyanation reagent are subjected to a reduction reaction represented by a formula shown in the description in an organic solvent under the protection of a gas at 20-100 DEG C under the action of a nickel catalyst, a reducing agent and H2O to prepare the alkenyl cyanide compounds represented by formula II. The preparation method of the invention, which adopts the cheap nickel as the catalytic system, has the advantages of simplicity in operation, mild reaction conditions, good compatibility of functional groups, wide application range of the substrate, high reaction efficiency and high yield, so the method has high application and promotion values.
- -
-
Paragraph 0100; 0130; 0170-0172
(2019/10/23)
-
- A [...] ligand, synthetic method and the application of the asymmetric reaction in
-
The invention relates to a novel chiral sulfur-alkene ligand and its synthesis method and use in an asymmetric reaction. The novel chiral sulfur-alkene ligand has a structural formula (I) or (II). In the structural formula (I) or (II), R1, R2, R3, R4, m and n are shown in the following description. The novel chiral sulfur-alkene ligand is simply prepared from aldehyde as a raw material. The novel chiral sulfur-alkene ligand can be used as a chiral ligand for an asymmetric addition reaction of boric acid and carbonyl compound (such as aromatic formaldehyde, isatin (Isatin) and trifluoroacetophenone) in the presence of a rhodium catalyst, and has a good yield and enantioselectivity.
- -
-
Paragraph 0178-0181
(2019/04/14)
-
- Iron-Catalyzed Alkylation of Nitriles with Alcohols
-
A general, efficient iron-catalyzed α-alkylation of nitriles with primary alcohols through a hydrogen-borrowing pathway has been developed, allowing a wide variety of alkylated nitriles to be readily accessible. Detailed mechanistic studies suggest that the reaction proceeds via an olefin intermediate with the turnover rate limited by the hydrogenation of the olefin with an iron hydride. Apart from participating in the alkylation, the nitrile is found to play an important role in promoting the formation of and stabilizing the active catalytic species.
- Ma, Wei,Cui, Suiya,Sun, Huamin,Tang, Weijun,Xue, Dong,Li, Chaoqun,Fan, Juan,Xiao, Jianliang,Wang, Chao
-
supporting information
p. 13118 - 13123
(2018/09/11)
-
- Highly active g-C3N4 as a solid base catalyst for knoevenagel condensation reaction under phase transfer conditions
-
In a promising approach, heterogeneous g-C3N4 as a solid base catalyst exhibits appreciable activity in Knoevenagel condensations at room temperature for the synthesis of substituted stilbene in presence of a crown-ether phase transfer catalyst. High yield of the product substituted stilbene were isolated in a very short reaction time period (~30 min). The solid base g-C3N4 catalyst was proven to be recyclable for several runs. Various aromatic substrates were screened using heterogeneous base g-C3N4 catalyst, exhibiting appreciable corresponding product yield (~99%) at room temperature.
- Sharma, Priti,Sasson, Yoel
-
p. 25589 - 25596
(2017/07/10)
-
- Process for the Catalytic Reversible Alkene-Nitrile Interconversion
-
The present invention refers to processes for catalytic reversible alkene-nitrile interconversion through controllable HCN-free transfer hydrocyanation.
- -
-
Page/Page column 27
(2017/09/02)
-
- An aqueous phase synthesis of cyano substituted styrene compound method
-
The invention discloses a method for aqueous-phase synthesizing cyan-substituted styrene compounds. The cyan-substituted styrene compounds are synthesized by taking water as a solvent and taking benzyl cyanide and aromatic aldehyde as materials through noevenagel condensation reaction, wherein the aromatic aldehyde is selected from formula shown in the specification. According to the invention, the reaction is carried out at a room temperature; relative to other high-temperature reactions in the prior art, not only is yield improved, but also energy resources are saved, and therefore, the method is beneficial to low-carbon harmless green engineering. White spherical precipitates are generated after reaction and dehydration, and the white spherical precipitates are washed in water to neutral, and dried to obtain a target product; and besides, the method is simple in synthetic steps, easy for treatment and high in yield.
- -
-
Paragraph 0047; 0048
(2016/12/16)
-
- Application of group v polyoxometalate as an efficient base catalyst: A case study of decaniobate clusters
-
The base catalytic activity of the decaniobate cluster (TMA)6[Nb10O28]·6H2O (TMA+ = tetramethylammonium cation) was studied theoretically and experimentally. Density functional theory calculations showed that the oxygen atoms in the cluster are highly negatively charged and suggested the possibility that the cluster can act as a base catalyst. We demonstrated for the first time that [Nb10O28]6- actually exhibits base catalytic activity for aldol-type condensation reactions including Knoevenagel and Claisen-Schmidt condensation reactions. The catalytic reactions proceeded under ambient conditions, suggesting that [Nb10O28]6- holds promise as a practical strong base catalyst.
- Hayashi, Shun,Yamazoe, Seiji,Koyasu, Kiichirou,Tsukuda, Tatsuya
-
p. 16239 - 16242
(2016/02/20)
-
- Polyoxometalate-Intercalated Layered Double Hydroxides as Efficient and Recyclable Bifunctional Catalysts for Cascade Reactions
-
The polyoxometalate (POM) intercalated layered double hydroxides (LDHs) have been widely used as heterogeneous catalysts. However, the application of POM-LDHs as bifunctional catalysts for cascade reaction has seldom been studied compared to the noble-metal-based catalysts. Herein, a series of POM-LDHs catalysts of Tris-LDH-X4(PW9)2 (X=Mn, Fe, Co, Ni, Cu, and Zn; Tris=Tris(hydroxymethtyl)aminomethane) have been prepared. The efficacy of Tris-LDH-Zn4(PW9)2 as efficient bifunctional catalyst has been demonstrated for cascade reactions involving oxidation of benzyl alcohol to benzaldehyde followed by Knoevenagel condensation with ethyl cyanoacetate to produce benzylidene ethyl cyanoacetate. The combination of POM's redox/acidic sites and LDHs's basic sites led to a composite catalyst with excellent activity (99 %) and selectivity (≥99 %) under mild and soluble-base-free conditions. This work offers a new design strategy for the fabrication of efficient bifunctional catalysts for the promotion of one-pot cascade reactions.
- Liu, Kai,Xu, Yanqi,Yao, Zhixiao,Miras, Haralampos N.,Song, Yu-Fei
-
p. 929 - 937
(2016/03/15)
-
- Thermal rearrangement of 2,3-diaryl-1-phthalimidoaziridines
-
2,3-Diaryl-1-phthalimidoaziridines and 2,3-diaryl-1-phthalimidoaziridine-2-carbonitriles were found to readily undergo thermal rearrangement into imines via 1,2-migration of the phthalimido group and accompanying C-C bond cleavage. Isomerization proceeds regioselectively with preferable migration to the electron-deficient carbon atom. Interestingly, this reaction was found to predominate even in the presence of dipolarophiles.
- Pankova, Alena S.,Sorokina, Mariia V.,Kuznetsov, Mikhail A.
-
p. 5381 - 5385
(2015/09/15)
-
- Ionic tagged amine supported on magnetic nanoparticles: Synthesis and application for versatile catalytic Knoevenagel condensation in water
-
Propylamine modified with imidazolium ionic moiety grafted onto magnetic nanoparticles (MNPs) was prepared and evaluated as a catalyst for Knoevenagel condensation in water at room temperature. The catalyst was efficient in the reaction to give the condensation products in good yields. It is worth noting that the ionic-tagged catalyst performed significantly better than its ionic tag-free counterpart. Finally, the catalyst could be reused for 8 times with a slight loss in its catalytic activity. the Partner Organisations 2014.
- Ying, Anguo,Qiu, Fangli,Wu, Chenglin,Hu, Huanan,Yang, Jianguo
-
p. 33175 - 33183
(2014/08/18)
-
- A basic germanodecatungstate with a - 7 charge: Efficient chemoselective acylation of primary alcohols
-
The synthesis of highly negatively charged polyoxometalates with electrically and structurally controlled uniform basic sites can lead to the unique base catalysis. In this work, a γ-Keggin germanodecatungstate, [γ-HGeW10O36]7- (A), having a -7 charge was, for the first time, successfully synthesized by the reaction of [γ-H2GeW10O36]6- with one equivalent of [(n-C4H9)4N]OH under non-aqueous conditions. The activities of germanodecatungstates for base-catalyzed reactions dramatically increased with increase in the number negative charges from -6 to -7. In the presence of A, various combinations of acylating agents and primary alcohols including those with acid-sensitive functional groups chemoselectively gave the desired acylated products in high yields even under the stoichiometric conditions.
- Sugahara, Kosei,Satake, Naoto,Kamata, Keigo,Nakajima, Takahito,Mizuno, Noritaka
-
supporting information
p. 13248 - 13252
(2015/01/09)
-
- Graphene based material as a base catalyst for solvent free Aldol condensation and Knoevenagel reaction at room temperature
-
Graphene oxide (GO) acts as a highly active heterogeneous base catalyst for a wide variety of reactions. Here we have described the catalytic activities of GO in the condensation reaction of various substituted benzaldehydes with acetophenone (aldol condensation) and with active methylene compound malononitrile (Knoevenagel reaction) at room temperature under solvent free condition. GO is characterized by powder X-ray diffraction (XRD), UV-visible spectra, Fourier transform infrared spectroscopy (FT-IR) and AFM. The experimental results showed that the GO had higher catalytic activity and it can be recycled without significant loss of its activity.
- Islam, Sk Manirul,Roy, Anupam Singha,Dey, Ram Chandra,Paul, Sumantra
-
-
- A Paal-Knorr approach to 3,4-diaryl-substituted pyrroles: Facile synthesis of lamellarins O and Q
-
A very simple, yet efficient synthetic methodology, to obtain 3,4-diaryl-substituted pyrroles is described. The approach is based on the Knoevenagel condensation between arylacetonitriles and substituted aromatic aldehydes, followed by conjugate addition of cyanide to afford succinonitriles in excellent yields. The products thus obtained were subjected to DIBAL-H reduction, followed by cyclization under acidic conditions to produce the corresponding pyrroles in good overall yields. The utility of this protocol is exemplified by the synthesis of the marine alkaloids lamellarins O and Q.
- Ramirez-Rodriguez, Armando,Mendez, Jose M.,Jimenez, Cristina C.,Leon, Fernando,Vazquez, Alfredo
-
p. 3321 - 3326,6
(2012/12/12)
-
- Monoalkylations with alcohols by a cascade reaction on bifunctional solid catalysts: Reaction kinetics and mechanism
-
A bifunctional catalytic system formed by Pd on MgO catalyzes the cascade process between benzyl alcohol and phenylacetonitrile, diethylmalonate and nitromethane, to give the respective α-monoalkylated products without external supply of hydrogen. The process involves a series of three cascade reactions occurring on different catalytic sites. The alcohol undergoes oxidation to the corresponding aldehyde with the simultaneous formation of a metal hydride; then, the aldehyde reacts with a nucleophile formed "in situ" to give an alkene, and finally, the hydrogen from the hydride is transferred to the alkene to give a new C-C bond. A kinetic study on the α-monoalkylation reaction of benzylacetonitrile with benzyl alcohol reveals that the rate-controlling step for the one-pot reaction sequence is the hydrogen transfer reaction from the surface hydrides to the olefin, and consequently, the global reaction rate is improved when decreasing the size of the Pd metal particle.
- Corma, Avelino,Rodenas, Tania,Sabater, Maria J.
-
experimental part
p. 319 - 327
(2011/05/14)
-
- Dialkylamino cyclopentadienyl ruthenium(II) complex-catalyzed α-alkylation of arylacetonitriles with primary alcohols
-
Aminocyclopentadienyl ruthenium complexes, [(η5-C 5H4NMe2)Ru(PPh3)2(CH 3CN)]+BF4- and [(η5- C5H4NEt2)Ru(PPh3) 2(CH3CN)]+BF4-, are moderately active catalysts for α-alkylation of arylacetonitriles with primary alcohols; on the other hand, the analogous unsubstituted cyclopentadienyl ruthenium complex [(η5-C5H 5)Ru(PPh3)2(CH3CN)] +BF4- shows very low catalytic activity. On the basis of experimental results and theoretical calculations, rationalization for the much higher catalytic activity of the aminocyclopentadienyl complexes over that of the unsubstituted Cp complex is provided. In the catalytic systems with the former, it is possible to regenerate the active solvento complexes via protonation of the metal hydride intermediates and subsequent ligand substitution; this process is, however, very nonfacile in the catalytic system with the latter. The Royal Society of Chemistry 2010.
- Cheung, Hung Wai,Li, Juan,Zheng, Wenxu,Zhou, Zhongyuan,Chiu, Yu Hin,Lin, Zhenyang,Lau, Chak Po
-
experimental part
p. 265 - 274
(2010/03/04)
-
- Spectroscopic characterization of halogen- and cyano-substituted pyridinevinylenes synthesized without catalyst or solvent
-
An efficient Knoevenagel route using green chemistry conditions was applied for the synthesis of halogen- and cyano- substituted pyridinevinylene compounds. Absorption and fluorescence emission spectra of these conjugated compounds were recorded and compared in order to evaluate the effect of substituents on the electronic properties of pyridinevinylene compounds. The substituents studied were terminal Cl and F, two or three aromatic rings, as well as a cyano group attached to a C=C double bond. The compounds synthesized are: (E)-2-(4-fluorostyryl)pyridine, (E)-2-(4-chlorostyryl)pyridine, (E)-4-(4-chlorostyryl)pyridine, 2,3-diphenylacrylonitrile, 3-phenyl-2-(pyridin-2-yl)acrylonitrile, 3-phenyl-2-(pyridin-3-yl)acrylonitrile, 2-phenyl-3-(pyridin-2-yl)acrylonitrile, 3,3′-(1,4-phenylene)bis(2-phenylacrylonitrile), 3,3′-(1,4-phenylene)bis(2-(pyridin-2-yl)acrylonitrile), and 3,3′-(1,4-phenylene)bis(2-(pyridin-3-yl)acrylonitrile). The solvent-free method used in this work allows obtaining each compound by controlling the reaction temperature. The compounds were characterized by infrared spectroscopy and 1H-NMR spectroscopy.
- Percino, M. Judith,Chapela, Victor M.,Montiel, Ling-Fa,Perez-Gutierrez, Enrique,Maldonado, J. Luis
-
experimental part
p. 360 - 367
(2011/10/11)
-
- Solvent-free condensation of arylacetonitrile with aldehydes
-
The condensation of a series of arylacetonitriles with aldehydes can be carried out by mixing equivalent amounts of reagents with neat powdered KOH at room temperature for 3-60 min depending on the aldehyde steric hindrance. At higher temperature (110°C), yields were generally higher and purity increased within very short reaction times (1-5 min). With pentamethylphenylacetonitrile, a phase transfer agent was necessary to give a satisfactory yield.
- Guillot, Régis,Loupy, André,Meddour, Abdelkrim,Pellet, Michèle,Petit, Alain
-
p. 10129 - 10137
(2007/10/03)
-
- P(RNCH2CH2)3N-Catalyzed synthesis of β-hydroxy nitriles
-
We herein report the successful synthesis of β-hydroxy nitriles in very good to excellent yields from aldehydes and ketones in a simple reaction that is promoted by strong nonionic bases of the title type. The reaction occurs in the presence of magnesium salts which activate the carbonyl group and stabilizes the enolate thus produced.
- Kisanga, Philip,McLeod, Dale,D'Sa, Bosco,Verkade, John
-
p. 3090 - 3094
(2007/10/03)
-
- Carbocyclic ring expansions with alkyne and carbene sources mediated by nickel(0) complexes: Structure of the critical organonickel intermediates
-
Experimental evidence is assessed concerning the nature of organonickel intermediates involved in the cyclotrimerization and the cyclotetramerization of alkynes, as well as the cross-oligomerization of alkynes with carbene sources, as mediated by nickel(0) complexes. In the former processes a sequential series of nickelacycloalkapolyenes are the productive intermediates and in the latter cross-oligomerizations nickel(0)-carbene complexes themselves are critical precursors to the ultimately generated carbocycles.
- Eisch, John J.,Aradi, Allen A.,Lucarelli, Michael A.,Qian, Yun
-
p. 1169 - 1184
(2007/10/03)
-
- Selective mono-benzylation of methylene active compounds with dibenzyl carbonate: benzylation of phenol
-
Dibenzyl carbonate (DBzlC) has been used to benzylate phenylacetonitrile, benzyl phenylacetate and phenol.In refluxing N,N-dimethylformamide (DMF) as solvent, and in the presence of K2CO3 phenol yielded benzyl phenyl ether and phenylacetonitrile the monobenzylated compound 2,3-diphenylpropionitrile.Likewise, in refluixing N,N-diethylformamide (DEF), benzyl phenyl acetate gave the benzyl 2,3-diphenylpropionate.Selectivity in mono-C-benzyl derivatives was 98-99percent at a conversion up to 90percent.Such unusually high selectivity is explained in terms of a mechanism involving, initially, carboxybenzylation followed by benzylation, rather than direct benzylation
- Selva, Maurizio,Marques, Carlos Alberto,Tundo, Pietro
-
p. 1889 - 1894
(2007/10/02)
-
- Direct synthesis of α,β-unsaturated nitriles in solid/liquid heterogeneous medium
-
α,β-unsaturated nitriles are obtained with high yields by condensation of diversely substituted aldehydes using nitriles in the presence of K2CO3. These basic active species avoids aldolisation generally observed in this type of reaction.
- Ladhar,El Gharbi
-
p. 413 - 417
(2007/10/02)
-
- Potassium Fluoride on Alumina. An Efficient Solid Base for Elimination, Addition, and Condensation
-
Alumina coated with potassium fluoride proved to be a versatile solid base for olefin- and acetylene-forming elimination, the Michael addition, aldol condensation, and the Darzens condensation.
- Yamawaki, Junko,Kawate, Takehiko,Ando, Takashi,Hanafusa, Terukiyo
-
p. 1885 - 1886
(2007/10/02)
-