1083-30-3

Acylation of α-aminoalkyl- copper and cuprate reagents with acid chlorides: Improved yields with soluble copper (I) salts

Dieter, R. Karl,Sharma, Ram R.,Ryan, Wendy

, p. 783 - 786 (1997)

α-Aminoalkylcopper reagents prepared from soluble CuX·2LiCI give modest to good yields of α-aminoketones upon reaction with acid chlorides, Higher yields are generally obtained with CuCl·2LiCl than with CuCN·2LiCl. Improved yields can be obtained by utilization of cuprate reagents prepared from CuCN·2LiCl and 2.0 equivalents of α-lithiocarbamates.

Sustainable and Selective Alkylation of Deactivated Secondary Alcohols to Ketones by Non-bifunctional Pincer N-heterocyclic Carbene Manganese

Lan, Xiao-Bing,Ye, Zongren,Liu, Jiahao,Huang, Ming,Shao, Youxiang,Cai, Xiang,Liu, Yan,Ke, Zhuofeng

, p. 2557 - 2563 (2020)

A sustainable and green route to access diverse functionalized ketones via dehydrogenative–dehydrative cross-coupling of primary and secondary alcohols is demonstrated. This borrowing hydrogen approach employing a pincer N-heterocyclic carbene Mn complex displays high activity and selectivity. A variety of primary and secondary alcohols are well tolerant and result in satisfactory isolated yields. Mechanistic studies suggest that this reaction proceeds via a direct outer-sphere mechanism and the dehydrogenation of the secondary alcohol substrates plays a vital role in the rate-limiting step.

Unexpected double benzylation of acetophenone under phase transfer catalysis conditions, acidity or π-π interaction effect?

Diez-Barra, Enrique,De la Hoz, Antonio,Loupy, Andre,Martinez-Gonzalez, Alfonso,Martinez-Merino, Victor,Merino, Sonia,Paugam, Renee,Sanchez-Verdu, Prado,Sansoulet, Jean,Torres, Jose

, p. 3659 - 3668 (1997)

A π-π interaction in the transition state of the benzylation of 1,3-diphenyl-1-propanone, the monobenzylation product of acetophenone, is proposed according to chemical, kinetic and theoretical approaches. Evidence for the existence of this kind of interaction in a transition state has been provided for the first time. The results obtained cannot be explained solely by the increased acidity but by considering the existence of a π-π interaction.

Palladium-Catalyzed Synthesis of Aryl Ketones from Boronic Acid and Carboxylic Acids or Anhysrides

Gossen, Lukas J.,Ghosh, K.

, (2001)

-

Pyracene-linked bis-imidazolylidene complexes of palladium and some catalytic benefits produced by bimetallic catalysts

Guisado-Barrios, Gregorio,Hiller, Joanna,Peris, Eduardo

, p. 10405 - 10411 (2013)

Two new palladium complexes with a pyracene-linked bis-imidazolylidene (pyrabim) group have been obtained and fully characterized. The related monometallic analogues were obtained from the coordination of an acetanaphthene-supported N-heterocyclic carbene

Cu-Ag/hydrotalcite catalysts for dehydrogenative cross-coupling of primary and secondary benzylic alcohols

Xu, Jin,Yue, Hongmei,Liu, Sheng,Wang, Hanfei,Du, Yuqun,Xu, Chunli,Dong, Wensheng,Liu, Chunling

, p. 24164 - 24174 (2016)

The development of new and inexpensive heterogeneous catalysts for direct C-C cross-coupling of primary and secondary alcohols is a challenging goal and has great importance in academic and industrial sectors. In this work Cu-Ag/hydrotalcite (Cu-Ag/HT) catalysts were prepared and tested for their impact on this cross-coupling. The effect of supports, including MgO, γ-Al2O3 and HT with different Mg : Al molar ratios, was investigated. It was found that the acidic or basic properties of the supports affected product selectivity. The roles of Cu and Ag sites in the cross-coupling were also investigated with the prepared Cu-Ag/HT catalyst demonstrating high activity and selectivity for the reaction. The yield-to-target product of β-phenylpropiophenone reached 99% after 1 h under optimum reaction conditions. The stability in air and reusability studies show that Cu-Ag/HT can be stored for 6 days and can be used five times without apparent deactivation, respectively.

The α-alkylation of ketones with alcohols in pure water catalyzed by a water-soluble Cp?Ir complex bearing a functional ligand

Meng, Chong,Xu, Jing,Tang, Yawen,Ai, Yao,Li, Feng

, p. 14057 - 14065 (2019)

A water-soluble dinuclear Cp?Ir complex bearing 4,4′,6,6′-tetrahydroxy-2,2′-bipyrimidine as a bridging ligand was found to be a highly effective catalyst for the α-alkylation of ketones with alcohols in pure water. In the presence of catalyst (0.5 mol%), a series of desirable products were obtained with high reaction economy under environmentally benign conditions. The importance of the hydroxy group in the ligand for catalytic hydrogen transfer was confirmed by mechanism experiments. Furthermore, the application of this catalytic system for the synthesis of a biologically active molecule donepezil in pure water has been accomplished. Notably, this research would facilitate the progress of C-C bond-forming reactions in water catalyzed by water-soluble metal-ligand bifunctional catalysts.

A Novel Route to Phenyl-substituted Pyridines by the Reaction of N-(1-Phenylvinyl)iminophosphoranes with α,β-Unsaturated Ketones

Kobayashi, Tomoshige,Nitta, Makoto

, p. 1549 - 1552 (1986)

The N-(1-phenylvinyl)iminotriphenylphosphorane or N-(1-phenylvinyl)iminotributylphosphorane reacted with α,β-unsaturated ketones to undergo a novel C-C bond formation followed by aza-Wittig reaction to result in the formation of phenyl-substituted pyridines.

CATALYTIC REDUCTIONS WITH FORMATE ION UNDER PHASE TRANSFER CONDITIONS

Bar, R.,Sasson, Y.

, p. 1709 - 1710 (1981)

Formate ion was extracted as ion pair into organic solvents and catalytically reduced chalcone in presence of homogeneous ruthenium phosphine complex.

Phosphine-Borane Frustrated Lewis Pairs Derived from a 1,1′-Disubstituted Ferrocene Scaffold: Synthesis and Hydrogenation Catalysis

Jian, Zhongbao,Krupski, Sergei,?koch, Karel,Kehr, Gerald,Daniliuc, Constantin G.,Císa?ová, Ivana,?těpni?ka, Petr,Erker, Gerhard

, p. 2940 - 2946 (2017)

(Dimesitylphosphino)ferrocene (FcPMes2) (1) reacted with HB(C6F5)2 (2 equiv) by disproportionation to give adduct FcPMes2·H2B(C6F5) (4) plus B(C6F5)3, whereas 1-(dimesitylphosphino)-1′-vinylferrocene (2) was cleanly hydroborated with HB(C6F5)2 to afford [Fe(??5-C5H4PMes2)(??5-C5H4CH2CH2B(C6F5)2)] (7). Compound 7 adopted an open non-interacting P/B frustrated Lewis pair (FLP) structure in the crystal state as well as in a solution. This frustrated Lewis pair heterolytically cleaved dihydrogen under mild conditions to give the respective zwitterionic [P]H+/[B]H- phosphonium/hydroborate product, [Fe(??5-C5H4PHMes2){??5-C5H4CH2CH2BH(C6F5)2}] (8), which served as a catalyst for the hydrogenation of the electron-rich ?€-systems (imine, enamine) as well as the electron-deficient carbon-carbon double and triple bonds in some enones and an ynone under more forcing conditions (50 bar H2 pressure, 50 °C).

Transfer hydrogenation of ketones catalyzed by 2,6‐bis(triazinyl)pyridine ruthenium complexes: The influence of alkyl arms

Wang, Liandi,Liu, Tingting

, (2019)

The transfer hydrogenation of ketones catalyzed by transition metal complexes has attracted much attention. A series of ruthenium(II) complexes bearing 2,6-bis(5,6-dialkyl-1,2,4-triazin-3-yl)pyridine ligands (R-BTPs) were synthesized and characterized by NMR analysis and X-ray diffraction. These ruthenium(II) complexes were applied in the transfer hydrogenation of ketones. Their different catalytic activity were attributed to the alkyl arms on the 2,6-bis(5,6-dialkyl-1,2,4-triazin-3-yl)pyridine. As the length of the alkyl arms rising, the catalytic activities of the complex catalysts decreased. By means of 0.4 mol % catalyst RuCl2(PPh3)(3-methylbutyl-BTP) in refluxing 2-propanol, a variety of ketones were reduced to their corresponding alcohols with >95% conversion over a period of 3 h.

Liquid phase hydrogenation of benzalacetophenone: Effect of solvent, catalyst support, catalytic metal and reaction conditions

Stolle, Achim,SchmOeger, Christine,Ondruschka, Bernd,Bonrath, Werner,Keller, Thomas F.,Jandt, Klaus D.

, p. 1312 - 1322 (2011)

Innovative catalysts based on a "porous glass" support material were developed and investigated for the reduction of benzalacetophenone. The easy preparation conditions and possibility to use different metals (e.g. Pd, Pt, Rh) for impregnation gave a broa

Catalytic transfer reduction of conjugated alkenes and an imine using polymer-supported formates

Basu, Basudeb,Bhuiyan, Md. Mosharef H.,Das, Pralay,Hossain, Ismail

, p. 8931 - 8934 (2003)

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.

Nanopalladium on polyethylenimine–grafted starch: An efficient and ecofriendly heterogeneous catalyst for Suzuki–Miyaura coupling and transfer hydrogenation reactions

Fu, Lixia,Deng, Wenxiu,Liu, Lujie,Peng, Yanqing

, (2017)

Functionalized natural polysaccharides are attractive supports for colloidal metal nanocatalysts due to their abundance, cheapness, biocompatibility and biodegradability. In this study, isocyanate–functionalized starch was prepared by treating with diisocyanate. Polyethylenimine grafted onto starch via the formation of urea linker. The palladium nanoparticles deposited starch PEIS@Pd(0) was obtained through a chelating–in situ reduction procedure. Characterization of these materials was done using Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X–ray diffraction, and inductive coupled plasma atomic emission spectrometry. The catalytic activity of PEIS@Pd(0) was then tested in two series of model reactions: Suzuki–Miyaura coupling and transfer hydrogenation. The catalyst could be recovered by simple filtration and was reused for five times without significant loss of catalytic activity, which confirmed the good stability of the catalyst.

Recyclable Polyisobutylene-Bound HMPA as an Organocatalyst in Recyclable Poly(α-olefin) Solvents

Fu, Ying-Hua,Bergbreiter, David E.

, p. 6050 - 6058 (2020)

This work describes the synthesis of a PIB-bound hexamethylphosphoramide (HMPA) analog and its applications as a recyclable catalyst in allylation of aldehydes and reduction of enones in a recyclable poly(α-olefin) (PAO) polymeric solvent. Kinetic studies of the allylation reaction show that this PIB-bound HMPA analog is as active as HMPA in dichloromethane and PAO and that this PIB-bound catalyst is comparably reactive in heptane and in a PAO solvent. The PIB-bound HMPA catalyst has high phase selective solubility in PAO versus a polar solvent. By using this catalyst in a nonvolatile separable PAO solvent, this catalyst recyclability can be coupled to solvent recyclability, something that is less feasible in a conventional heptane solvent. The result is good recycling of catalyst and solvent through at least 5 cycles using simple gravity-based liquid/liquid extractions. This is in contrast to HMPA or conventional solvents which are less recyclable.

Copper-catalyzed tandem phosphination-decarboxylation-oxidation of alkynyl acids with H-phosphine oxides: A facile synthesis of β-ketophosphine oxides

Zhang, Pengbo,Zhang, Liangliang,Gao, Yuzhen,Xu, Jian,Fang, Hua,Tang, Guo,Zhao, Yufen

, p. 7839 - 7842 (2015)

The general method for the tandem phosphination-decarboxylation-oxidation of alkynyl acids under aerobic conditions has been developed. In the presence of CuSO4·5H2O and TBHP, the reactions provide a novel access to β-ketophosphine oxides in good to excellent yields. This transformation allows the direct formation of a P-C bond and the construction of a keto group in one reaction.

Capturing the Monomeric (L)CuH in NHC-Capped Cyclodextrin: Cavity-Controlled Chemoselective Hydrosilylation of α,β-Unsaturated Ketones

Bistri-Aslanoff, Olivia,Derat, Etienne,Leloux, Sébastien,Leyssens, Tom,Ménand, Micka?l,Meijide Suárez, Jorge,Riant, Olivier,Roland, Sylvain,Sollogoub, Matthieu,Xu, Guangcan,Zhang, Pinglu,Zhang, Yongmin

, p. 7591 - 7597 (2020)

The encapsulation of copper inside a cyclodextrin capped with an N-heterocyclic carbene (ICyD) allowed both to catch the elusive monomeric (L)CuH and a cavity-controlled chemoselective copper-catalyzed hydrosilylation of α,β-unsaturated ketones. Remarkably, (α-ICyD)CuCl promoted the 1,2-addition exclusively, while (β-ICyD)CuCl produced the fully reduced product. The chemoselectivity is controlled by the size of the cavity and weak interactions between the substrate and internal C?H bonds of the cyclodextrin.

Iridium(III)- benzoxazolyl and benzothiazolyl phosphine ligands catalyzed versatile alkylation reactions with alcohols and the synthesis of quinolines and indole

Huang, Shuang,Wu, Si-Peng,Zhou, Quan,Cui, He-Zhen,Hong, Xi,Lin, Yue-Jian,Hou, Xiu-Feng

, p. 14 - 23 (2018)

A series of benzoxazolyl and benzothiazolyl phosphine ligands 4a-4g were synthesized and characterized, which prepared from commercially available 2-aminophenol/2-aminobenzenethiol and 2-bromobenzaldehyde via cyclization and phosphination. The representative ligands 4c and 4e were determined by single-crystal X-ray diffraction. The corresponding iridium complexes could be generated in situ when [Cp*IrCl2]2 (Cp* = pentamethylcyclopentadienyl) encountered ligands. The molecular structures of complexes 5c and 5e were crystallographically characterized. The dihedral angles of N (1)-C (1)-C (8)-C (9) showed an increasing twist compared with the corresponding ligand. The iridium (III) catalysts were screened, [Cp*IrCl2]2/4a proved to be the optimal catalyst, which exhibited efficient catalytic activity toward versatile alkylations including ketones, secondary alcohols and amines with primary alcohols. Additionally, the synthesis of quinolines from ketones with 2-aminobenzyl alcohol by intermolecular cyclization and indole from 2-(2-aminophenyl)ethanol by intramolecular cyclization were achieved under the optimized conditions.

Use of 13C Isotope Shifts for Assignment of Deuterium Labelling Sites in 1,3-Diphenylpropan-1-one

Bar, Raphael,Sasson, Yoel,Blum, Jochanan

, p. 565 - 568 (1984)

13C NMR spectroscopy was used for the unequivocal analysis of the mixture of products of RuCl23-catalysed transfer deuteriation of benzylideneacetophenone by (a) DCOONa/H2O, (b) HCOONa/D2O and (c) DCOONa/D2O.Signal assignments in the 13C spectra were obtained mainly from the deuterium-induced 13C isotope shifts.The geminal 13C-2H shift of the β-carbon of deuteriated 1,3-diphenylpropan-1-one is almost twice that for the α-carbon.

Polymer-stabilized palladium nanoparticles for the chemoselective transfer hydrogenation of α,β-unsaturated carbonyls: Single-step bottom-Up approach

Mahato, Sanjit K.,Ul Islam, Rafique,Acharya, Chiranjit,Witcomb, Michael J.,Mallick, Kaushik

, p. 1419 - 1426 (2014)

Polypyrrole stabilised palladium nanoparticles show good catalytic efficiency for the chemoselective transfer hydrogenation of α,β- unsaturated carbonyl compounds. The catalyst is very specific and selectively hydrogenates the olefins or acetylenes only,

Synthesis of nitrogen heterocycles by intramolecular Michael type of amination via reduction of imines with di-n-butyliodotin hydride (n-Bu2SnIH)

Suwa, Toshihiro,Shibata, Ikuya,Nishino, Keita,Baba, Akio

, p. 1579 - 1581 (1999)

(matrix presented). Novel nitrogen heterocycles were prepared by a one-pot procedure involving the reductive amination of the bifunctional substrates containing an aldehyde and enone groups with di-n-butyliodotin hydride (n-Bu2SnIH).

Blum et al.

, p. 1015 (1972)

Ela,Cram

, p. 5777,5788 (1966)

Reductions of α,β-unsaturated ketones by NaBH4 or NaBH4 + CoCl2: Selectivity control by water or by aqueous micellar solutions

Aramini, Andrea,Brinchi, Lucia,Germani, Raimondo,Savelli, Gianfranco

, p. 1793 - 1797 (2000)

Operationally simple and environmentally benign procedures have been developed to selectively reduce different α,β-unsaturated ketones, 4,4- dimethylcyclohex-2-ene-1-one (1), isophorone (2), benzylideneacetone (3), chalcone (4) by NaBH4 or by the system NaBH4 + COCl2. Alternative reaction media to the extensively used MeOH have been explored, and new procedures take advantage of the acceleration and chemoselectivity induced by water or by aqueous micellar solutions. It was possible to selectively and quantitatively afford pure products of 1,2 and of 1,4 reduction as well as the totally reduced compounds (yield and selectivity > 90%) by simple changes in the experimental conditions.

Synthesis of Phosphanylferrocenecarboxamides Bearing Guanidinium Substituents and Their Application in the Palladium-Catalyzed Cross-Coupling of Boronic Acids with Acyl Chlorides

Charvátová, Hana,Císa?ová, Ivana,?těpni?ka, Petr

, p. 288 - 296 (2017)

Phosphanylferrocene donors bearing polar guanidinium substituents, namely acylguanidinium chloride, [Ph2PfcCONHC(NH2)NH2]Cl (1), and amidoguanidinium chloride, [Ph2PfcCONHCH2CH2NHC(NH2)NH2]Cl (2; fc = ferrocene-1,1′-diyl), have been prepared and characterized. As functional phosphane donors, they were employed in the synthesis of PdIIcomplexes bearing 2-[(dimethylamino)methyl-κN]phenyl-κC1(LNC) and η3-allyl supporting ligands, [(LNC)PdCl(L-κP)] and [(η3-C3H5)PdCl(L-κP)] (L = 1 and 2), respectively. These defined complexes as well as their surrogates generated in situ from the respective palladium(II) precursor and the phosphanylferrocene ligand were evaluated as catalysts for the coupling of boronic acids with acyl chlorides to give ketones in an aqueous biphasic system. The coupling reaction proceeded best with a simple catalyst formed from Pd(OAc)2and ligand 2, which (at 0.2 mol-% Pd loading) produced substituted benzophenones from benzoyl chlorides and benzeneboronic acids in very good yields. These yields could then be further improved by a proper choice of the reaction partners. Analogous reactions involving aliphatic substrates generally afforded lower yields.

Electronically tuneable orthometalated RuII–NHC complexes as efficient catalysts for C–C and C–N bond formations via borrowing hydrogen strategy

Illam, Praseetha Mathoor,Rit, Arnab

, p. 67 - 74 (2022/01/19)

The catalytic activities of a series of simple and electronically tuneable cyclometalated RuII–NHC complexes (2a–d) were explored in various C–C/N bond formations following the borrowing hydrogen process. Slight modifications in the ligand backbone were noted to tune the activities of these complexes. Among them, the complex 2d featuring a 1,2,4-triazolylidene donor with a 4-NO2–phenyl substituent displayed the highest activity for the coupling of diverse secondary and primary alcohols with a low catalyst loading of 0.01 mol% and a sub-stoichiometric amount of inexpensive KOH base. The efficacy of this simple system was further showcased in the challenging one-pot unsymmetrical double alkylation of secondary alcohols using different primary alcohols. Moreover, the complex 2d also effectively catalyses the selective mono-N-methylation of various aromatic and aliphatic primary amines using methanol to deliver a range of N-methyl amines. Mechanistically, the β-alkylation reaction follows a borrowing hydrogen pathway which was established by the deuterium labelling experiment in combination with various control experiments. Intriguingly, in situ1H NMR and ESI-MS analyses evidently suggested the involvement of a Ru–H species in the catalytic cycle and further, the kinetic studies revealed a first order dependence of the reaction rate on the catalyst as well as the alcohol concentrations.

Nickel-Catalyzed Selective Synthesis of α-Alkylated Ketones via Dehydrogenative Cross-Coupling of Primary and Secondary Alcohols

Bains, Amreen K,Biswas, Ayanangshu,Adhikari, Debashis

supporting information, p. 47 - 52 (2021/10/14)

Herein, we describe an isolable, air-stable, homogeneous, nickel catalyst that performs dehydrogenative cross-coupling reaction between secondary and primary alcohols to result α-alkylated ketone products selectively. The sequence of steps involve in this one-pot reaction is dehydrogenation of both alcohols, condensation between the ketone and the aldehyde, and hydrogenation of the in situ-generated α,β-unsaturated ketone. Preliminary mechanistic investigation hints a radical mechanism following borrowing hydrogen reaction. (Figure presented.).

Synthesis of α-Alkylated Ketones via Selective Epoxide Opening/Alkylation Reactions with Primary Alcohols

Gen?, Serta?,Gülcemal, Süleyman,Günnaz, Salih,?etinkaya, Bekir,Gülcemal, Derya

supporting information, p. 5229 - 5234 (2021/07/19)

A new method for converting terminal epoxides and primary alcohols into α-alkylated ketones under borrowing hydrogen conditions is reported. The procedure involves a one-pot epoxide ring opening and alkylation via primary alcohols in the presence of an N-heterocyclic carbene iridium(I) catalyst, under aerobic conditions, with water as the side product.