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Chemical synthesis of mesoporous carbon nitrides using hard templates and their use as a metal-free catalyst for Friedel-Crafts reaction of benzene
(Figure Presented) In the footsteps of Liebig and Berzelius: A material first synthesized in 1834, carbon nitride (C3N4), was synthesized in a graphitic mesoporous form by using silica nanoparticles as templates. The resulting electron-rich solid is an active catalyst for the Friedel-Crafts acylation of benzene with hexanoyl chloride. Presumably the catalysis arises from a shift of electron density from the MOs of the catalyst to the unoccupied orbitals of benzene (see picture).
Goettmann, Frederic,Fischer, Anna,Antonietti, Markus,Thomas, Arne
p. 4467 - 4471
(2006)
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Rh-Catalyzed Coupling of Aldehydes with Allylboronates Enables Facile Access to Ketones
We present herein a novel strategy for the preparation of ketones from aldehydes and allylic boronic esters. This reaction involves the allylation of aldehydes with allylic boronic esters and the Rh-catalyzed chain-walking of homoallylic alcohols. The key to this successful development is the protodeboronation of alkenyl borylether intermediate via a tetravalent borate anion species in the presence of KHF2 and MeOH. This approach features mild reaction conditions, broad substrate scope, and excellent functional group tolerance. Mechanistic studies also supported that the tandem allylation and chain-walking process were involved.
Zhang, Kezhuo,Huang, Jiaxin,Zhao, Wanxiang
supporting information

(2022/02/21)

Combined Theoretical and Experimental Studies Unravel Multiple Pathways to Convergent Asymmetric Hydrogenation of Enamides
We present a highly efficient convergent asymmetric hydrogenation of E/Z mixtures of enamides catalyzed by N,P-iridium complexes supported by mechanistic studies. It was found that reduction of the olefinic isomers (E and Z geometries) produces chiral amides with the same absolute configuration (enantioconvergent hydrogenation). This allowed the hydrogenation of a wide range of E/Z mixtures of trisubstituted enamides with excellent enantioselectivity (up to 99% ee). A detailed mechanistic study using deuterium labeling and kinetic experiments revealed two different pathways for the observed enantioconvergence. For α-aryl enamides, fast isomerization of the double bond takes place, and the overall process results in kinetic resolution of the two isomers. For α-alkyl enamides, no double bond isomerization is detected, and competition experiments suggested that substrate chelation is responsible for the enantioconvergent stereochemical outcome. DFT calculations were performed to predict the correct absolute configuration of the products and strengthen the proposed mechanism of the iridium-catalyzed isomerization pathway.
Yang, Jianping,Massaro, Luca,Krajangsri, Suppachai,Singh, Thishana,Su, Hao,Silvi, Emanuele,Ponra, Sudipta,Eriksson, Lars,Ahlquist, M?rten S. G.,Andersson, Pher G.
supporting information
p. 21594 - 21603
(2021/12/27)

Nickel-Mediated Photoreductive Cross Coupling of Carboxylic Acid Derivatives for Ketone Synthesis**
A simple visible light photochemical, nickel-catalyzed synthesis of ketones from carboxylic acid-derived precursors is presented. Hantzsch ester (HE) functions as a cheap, green and strong photoreductant to facilitate radical generation and also engages in the Ni-catalytic cycle to restore the reactive species. With this dual role, HE allows for the coupling of a large variety of radicals (1°,2°, benzylic, α-oxy & α-amino) with aroyl and alkanoyl moieties, a new feature in reactions of this type. With both precursors deriving from abundant carboxylic acids, this protocol is a welcome addition to the organic chemistry toolbox. The reaction proceeds under mild conditions without the need for toxic metal reagents or bases and shows a wide scope, including pharmaceuticals and complex molecular architectures.
Brauer, Jan,Quraishi, Elisabeth,Kammer, Lisa Marie,Opatz, Till
p. 18168 - 18174
(2021/11/30)

Direct conversion of secondary propargyl alcohols into 1,3-di-arylpropanoneviaDBU promoted redox isomerization and palladium assisted chemoselective hydrogenation in a single pot operation
Palladium(ii)acetate is found to be an efficient catalyst for the single-step conversion of secondary propargyl alcohols to 1,3-diarylpropanone derivatives under mild basic conditions. The reaction is believed to proceedviaredox isomerisation of secondary propargyl alcohols followed by chemoselective reduction of an enone double bond with formic acid as an adequate hydrogen donor. A large number of 1,3-diarylpropanone derivatives may readily be prepared from a milligram to a multigram scale.
Bera, Mrinal K.,Chandra, Shubhadeep,De, Rimpa,Savarimuthu, S. Antony
p. 17871 - 17877
(2021/10/12)

A Proton-Responsive Pyridyl(benzamide)-Functionalized NHC Ligand on Ir Complex for Alkylation of Ketones and Secondary Alcohols
A Cp*Ir(III) complex (1) of a newly designed ligand L1 featuring a proton-responsive pyridyl(benzamide) appended on N-heterocyclic carbene (NHC) has been synthesized. The molecular structure of 1 reveals a dearomatized form of the ligand. The protonation of 1 with HBF4 in tetrahydrofuran gives the corresponding aromatized complex [Cp*Ir(L1H)Cl]BF4 (2). Both compounds are characterized spectroscopically and by X-ray crystallography. The protonation of 1 with acid is examined by 1H NMR and UV-vis spectra. The proton-responsive character of 1 is exploited for catalyzing α-alkylation of ketones and β-alkylation of secondary alcohols using primary alcohols as alkylating agents through hydrogen-borrowing methodology. Compound 1 is an effective catalyst for these reactions and exhibits a superior activity in comparison to a structurally similar iridium complex [Cp*Ir(L2)Cl]PF6 (3) lacking a proton-responsive pendant amide moiety. The catalytic alkylation is characterized by a wide substrate scope, low catalyst and base loadings, and a short reaction time. The catalytic efficacy of 1 is also demonstrated for the syntheses of quinoline and lactone derivatives via acceptorless dehydrogenation, and selective alkylation of two steroids, pregnenolone and testosterone. Detailed mechanistic investigations and DFT calculations substantiate the role of the proton-responsive ligand in the hydrogen-borrowing process.
Kaur, Mandeep,U Din Reshi, Noor,Patra, Kamaless,Bhattacherya, Arindom,Kunnikuruvan, Sooraj,Bera, Jitendra K.
supporting information
p. 10737 - 10748
(2021/06/15)

Metal- And additive-free C-H oxygenation of alkylarenes by visible-light photoredox catalysis
A metal- and additive-free methodology for the highly selective, photocatalyzed C-H oxygenation of alkylarenes under air to the corresponding carbonyls is presented. The process is catalyzed by an imide-acridinium that forms an extremely strong photooxidant upon visible light irradiation, which is able to activate inert alkylarenes such as toluene. Hence, this is an easy to perform, sustainable and environmentally friendly oxidation that provides valuable carbonyls from abundant, readily available compounds.
García Manche?o, Olga,Kuhlmann, Jan H.,Pérez-Aguilar, María Carmen,Piekarski, Dariusz G.,Uygur, Mustafa
supporting information
p. 3392 - 3399
(2021/05/21)

Selective catalytic synthesis of α-alkylated ketones and β-disubstituted ketones via acceptorless dehydrogenative cross-coupling of alcohols
Herein, a phosphine-free pincer ruthenium(III) catalyzed β-alkylation of secondary alcohols with primary alcohols to α-alkylated ketones and two different secondary alcohols to β-branched ketones are reported. Notably, this transformation is environmentally benign and atom efficient with H2O and H2 gas as the only byproducts. The protocol is extended to gram-scale reaction and for functionalization of complex vitamin E and cholesterol derivatives.
Bhattacharyya, Dipanjan,Sarmah, Bikash Kumar,Nandi, Sekhar,Srivastava, Hemant Kumar,Das, Animesh
supporting information
p. 869 - 875
(2021/02/06)

Iron-Catalyzed C-C Single-Bond Cleavage of Alcohols
An iron-catalyzed deconstruction/hydrogenation reaction of alcohols through C-C bond cleavage is developed through photocatalysis, to produce ketones or aldehydes as the products. Tertiary, secondary, and primary alcohols bearing a wide range of substituents are suitable substrates. Complex natural alcohols can also perform the transformation selectively. A investigation of the mechanism reveals a procedure that involves chlorine radical improved O-H homolysis, with the assistance of 2,4,6-collidine.
Liu, Wei,Wu, Qiang,Wang, Miao,Huang, Yahao,Hu, Peng
supporting information
p. 8413 - 8418
(2021/11/01)

Method for preparing aldehyde/ketone by breaking C-C key
The invention discloses a method for preparing aldehyde/ketone by breaking C-C bonds, and the method comprises the following steps of anaerobic condition. In an organic solvent system, an alcohol is used as a reaction raw material, and the C-C bond is selectively broken under the common action of an iron catalyst, an organic base and an additive to obtain aldehyde/ketone. The method is low in cost, easy to obtain, wide in substrate range, simple and product in post-treatment and high in purity, a new synthetic route and a method are developed for an aldehyde ketone compound, and the method has good application potential and research value.
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Paragraph 0050-0064; 0123-0143

(2021/11/19)

Redox-driven deracemization of secondary alcohols by sequential ether/O2-mediated oxidation and Ru-catalyzed asymmetric reduction
The deracemization of benzylic alcohols has been achieved using a redox-driven one-pot two-step process. The racemic alcohols were oxidized by bis(methoxypropyl) ether and oxygen to give the ketone intermediates, followed by an asymmetric transfer hydrogenation with a chiral ruthenium catalyst. This compatible oxidation/reduction process gave the enantiomerically enriched alcohols with up to 95% ee values.
Yang, Bing,Cui, Peng,Chen, Yongsheng,Liu, Qixing,Zhou, Haifeng
supporting information

(2020/10/14)

Synergistic Activation of Amides and Hydrocarbons for Direct C(sp3)–H Acylation Enabled by Metallaphotoredox Catalysis
The utilizations of omnipresent, thermodynamically stable amides and aliphatic C(sp3)?H bonds for various functionalizations are ongoing challenges in catalysis. In particular, the direct coupling between the two functional groups has not been realized. Here, we report the synergistic activation of the two challenging bonds, the amide C?N and unactivated aliphatic C(sp3)?H, via metallaphotoredox catalysis to directly acylate aliphatic C?H bonds utilizing amides as stable and readily accessible acyl surrogates. N-acylsuccinimides served as efficient acyl reagents for the streamlined synthesis of synthetically useful ketones from simple C(sp3)?H substrates. Detailed mechanistic investigations using both computational and experimental mechanistic studies were performed to construct a detailed and complete catalytic cycle. The origin of the superior reactivity of the N-acylsuccinimides over other more reactive acyl sources such as acyl chlorides was found to be an uncommon reaction pathway which commences with C?H activation prior to oxidative addition of the acyl substrate.
Baik, Mu-Hyun,Choi, Seulhui,Hong, Soon Hyeok,Lee, Geun Seok,Won, Joonghee
p. 16933 - 16942
(2020/08/03)

A Bifunctional Iron Nanocomposite Catalyst for Efficient Oxidation of Alkenes to Ketones and 1,2-Diketones
We herein report the fabrication of a bifunctional iron nanocomposite catalyst, in which two catalytically active sites of Fe-Nx and Fe phosphate, as oxidation and Lewis acid sites, were simultaneously integrated into a hierarchical N,P-dual doped porous carbon. As a bifunctional catalyst, it exhibited high efficiency for direct oxidative cleavage of alkenes into ketones or their oxidation into 1,2-diketones with a broad substrate scope and high functional group tolerance using TBHP as the oxidant in water under mild reaction conditions. Furthermore, it could be easily recovered for successive recycling without appreciable loss of activity. Mechanistic studies disclose that the direct oxidation of alkenes proceeds via the formation of an epoxide as intermediate followed by either acid-catalyzed Meinwald rearrangement to give ketones with one carbon shorter or nucleophilic ring-opening to generate 1,2-diketones in a cascade manner. This study not only opens up a fancy pathway in the rational design of Fe-N-C catalysts but also offers a simple and efficient method for accessing industrially important ketones and 1,2-diketones from alkenes in a cost-effective and environmentally benign fashion.
Ma, Zhiming,Ren, Peng,Song, Tao,Xiao, Jianliang,Yang, Yong,Yuan, Youzhu
p. 4617 - 4629
(2020/05/19)

Rhodium-Catalyzed Remote Isomerization of Alkenyl Alcohols to Ketones
We develop herein an efficient rhodium-catalyzed remote isomerization of aromatic and aliphatic alkenyl alcohols into ketones. This catalytic process, with a commercially available catalyst and ligand ([RhCl(cod)]2 and Xantphos), features high efficiency, low catalyst loading, good functional group tolerance, a broad substrate scope, and no (sub)stoichiometric additive. Preliminary mechanistic studies suggest that this transformation involves an iterative dissociative β-hydride elimination-migration insertion process.
Dong, Wenke,Yang, Hongxuan,Yang, Wen,Zhao, Wanxiang
supporting information

(2020/02/28)

Phosphine-free pincer-ruthenium catalyzed biofuel production: High rates, yields and turnovers of solventless alcohol alkylation
Phosphine-free pincer-ruthenium carbonyl complexes based on bis(imino)pyridine and 2,6-bis(benzimidazole-2-yl) pyridine ligands have been synthesized. For the β-alkylation of 1-phenyl ethanol with benzyl alcohol at 140 °C under solvent-free conditions, (Cy2NNN)RuCl2(CO) (0.00025 mol%) in combination with NaOH (2.5 mol%) was highly efficient (ca. 93% yield, 372?000 TON at 12?000 TO h-1). These are the highest reported values hitherto for a ruthenium based catalyst. The β-alkylation of various alcohol combinations was accomplished with ease which culminated to give 380?000 TON at 19?000 TO h-1 for the β-alkylation of 1-phenyl ethanol with 3-methoxy benzyl alcohol. DFT studies were complementary to mechanistic studies and indicate the β-hydride elimination step involving the extrusion of acetophenone to be the overall RDS. While the hydrogenation step is favored for the formation of α-alkylated ketone, the alcoholysis step is preferred for the formation of β-alkylated alcohol. The studies were extended for the upgradation of ethanol to biofuels. Among the pincer-ruthenium complexes based on bis(imino)pyridine, (Cy2NNN)RuCl2(CO) provided high productivity (335 TON at 170 TO h-1). Sterically more open pincer-ruthenium complexes such as (Bim2NNN)RuCl2(CO) based on the 2,6-bis(benzimidazole-2-yl) pyridine ligand demonstrated better reactivity and gave not only good ethanol conversion (ca. 58%) but also high turnovers (ca. 2100) with a good rate (ca. 710 TO h-1). Kinetic studies indicate first order dependence on concentration of both the catalyst and ethanol. Phosphine-free catalytic systems operating with unprecedented activity at a very low base loading to couple lower alcohols to higher alcohols of fuel and pharmaceutical importance are the salient features of this report. This journal is
Das, Babulal,Das, Kanu,Kumar, Akshai,Srivastava, Hemant Kumar,Yasmin, Eileen
p. 8347 - 8358
(2020/12/31)

Cyclometalated Ruthenium Pincer Complexes as Catalysts for the α-Alkylation of Ketones with Alcohols
Ruthenium PNP pincer complexes bearing supplementary cyclometalated C,N-bound ligands have been prepared and fully characterized for the first time. By replacing CO and H? as ancillary ligands in such complexes, additional electronic and steric modifications of this topical class of catalysts are possible. The advantages of the new catalysts are demonstrated in the general α-alkylation of ketones with alcohols following a hydrogen autotransfer protocol. Herein, various aliphatic and benzylic alcohols were applied as green alkylating agents for ketones bearing aromatic, heteroaromatic or aliphatic substituents as well as cyclic ones. Mechanistic investigations revealed that during catalysis, Ru carboxylate complexes are predominantly formed whereas neither the PNP nor the CN ligand are released from the catalyst in significant amounts.
Piehl, Patrick,Amuso, Roberta,Alberico, Elisabetta,Junge, Henrik,Gabriele, Bartolo,Neumann, Helfried,Beller, Matthias
supporting information
p. 6050 - 6055
(2020/03/13)

Mn-Enabled Radical-Based Alkyl-Alkyl Cross-Coupling Reaction from 4-Alkyl-1,4-dihydropyridines
Highly efficient alkylation of β-chloro ketones and their derivatives was achieved by means of domino dehydrochlorination/Mn-enabled radical-based alkyl-alkyl cross-coupling reaction. In situ-generated α,β-unsaturated ketones and their analogues were identified as the reaction intermediates. Known bioactive compounds, such as melperone and azaperone, could be easily prepared from β-chloropropiophenone in two steps.
Wang, Jie,Pang, Yu-Bo,Tao, Na,Zeng, Run-Sheng,Zhao, Yingsheng
p. 15315 - 15322
(2019/11/19)

Method for synthesizing chiral alcohol through deracemization
The invention relates to a method for synthesizing chiral alcohol (formula I) through deracemization. The preparation method provided by the invention is one-pot asymmetric cascade reaction, and comprises the following steps: 1), with racemic alcohol (formula II) as a raw material and dipropylene glycol dimethyl ether as a solvent, reacting at 120 DEG C for 12 hours, and performing a dehydrogenation reaction to produce intermediate ketone (formula III); and 2), directly adding 2.5mol% of a chiral diamine metal ruthenium complex as a catalyst into a reaction system, with 5 equivalents of sodiumformate as a hydrogen source and a mixed solution of methanol and water as a solvent, reacting at 50 DEG C for 12 hours under the protection of nitrogen, and performing asymmetric transfer hydrogenation to obtain the chiral alcohol (formula I). The method has the advantages of environment-friendly synthesis such as a simple and mild reaction condition, step economy and atomic economy; and in addition, a substrate has a wide application range, the enantioselectivity is high, and the method has a broad application prospect in synthesis of chiral alcohol pharmaceutical intermediates and fine chemical raw materials.
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Paragraph 0071-0073

(2019/07/29)

Chemoselective Synthesis of Aryl Ketones from Amides and Grignard Reagents via C(O)-N Bond Cleavage under Catalyst-Free Conditions
Conversion of a wide range of N-Boc amides to aryl ketones was achieved with Grignard reagents via chemoselective C(O)-N bond cleavage. The reactions proceeded under catalyst-free conditions with different aryl, alkyl, and alkynyl Grignard reagents. α-Ketoamide was successfully converted to aryl diketones, while α,β-unsaturated amide underwent 1,4-addition followed by C(O)-N bond cleavage to provide diaryl propiophenones. N-Boc amides displayed higher reactivity than Weinreb amides with Grignard reagents. A broad substrate scope, excellent yields, and quick conversion are important features of this methodology.
Sureshbabu, Popuri,Azeez, Sadaf,Muniyappan, Nalluchamy,Sabiah, Shahulhameed,Kandasamy, Jeyakumar
p. 11823 - 11838
(2019/10/02)

Ligand-controlled phosphine-free Co(II)-catalysed cross-coupling of secondary and primary alcohols
Cobalt(II) complexes (5 mol% Co) bearing phosphine-free N?N?N pincer ligands efficiently catalyze C–C coupling of secondary and primary alcohols to selectively form α-alkylated ketones with a good functional group compatibility using NaOH (20 mol%) as a base at 120 °C. The NH group on the N?N?N–Co(II) precatalyst controls the activity and selectivity. This simple catalytic system is involved in the synthesis of quinolones via the dehydrogenative annulation of 2-aminobenzyl alcohols with secondary alcohols.
Zhang, Shi-Qi,Guo, Bin,Xu, Ze,Li, Hong-Xi,Li, Hai-Yan,Lang, Jian-Ping
(2019/10/28)

Ruthenium-Catalyzed β-Alkylation of Secondary Alcohols and α-Alkylation of Ketones via Borrowing Hydrogen: Dramatic Influence of the Pendant N-Heterocycle
Three bidentate ruthenium(II) complexes with a pyridonate fragment were prepared and fully characterized. These complexes are structurally similar, but differ in their pendant substituents. Complex 1 contains a phenyl unit, whereas complexes 2 and 3 have uncoordinated thienyl and thiazolyl groups, respectively. These complexes were tested as catalysts for β-alkylation of secondary alcohols with primary alcohols, and 3 shows the highest activity, suggesting the thiazolyl ring participates in the catalytic process. Furthermore, 3 is an excellent catalyst for α-alkylation of ketones with primary alcohols. Various α-alkylated ketones were synthesized in high yields, by using 0.05 mol % 3 and 0.25 equiv of t-BuOK within 30 min.
Zhang, Chong,Zhao, Jiong-Peng,Hu, Bowen,Shi, Jing,Chen, Dafa
p. 654 - 664
(2019/02/17)

Rational Design of a Metallocatalytic Cavitand for Regioselective Hydration of Specific Alkynes
The synthesis of a functionalized supramolecular cavitand with inwardly oriented AuI and P=O moieties was explored, including its catalytic proclivity in the selective hydration of internal alkynes. The cavitand works as a supramolecular flask device: AuI coordinates to the triple bond, the P=O moiety connects with a H2O molecule, and the cavity favors folding of a single alkynyl side chain. Several tests of different substrate patterns indicated that the cavity was substrate specific, similar to enzymatic catalysis.
Endo, Naoki,Inoue, Mami,Iwasawa, Tetsuo
supporting information
p. 1136 - 1140
(2018/03/13)

Dirhodium(ii)/P(t-Bu)3 catalyzed tandem reaction of α,β-unsaturated aldehydes with arylboronic acids
Phosphine ligated dirhodium(ii) acetate is advocated as a catalyst for the synthesis of aryl alkyl ketones by the tandem reaction of α,β-unsaturated aromatic or aliphatic aldehydes with arylboronic acids. This tandem procedure included arylation followed by the isomerization reaction. This method exhibits good functional group tolerance and has a broad substrate scope. With the conjugated aldehydes, the one-step synthesis of γ,δ-unsaturated ketones was realized through this reaction. It is noteworthy that the length of the Rh-P bond is an important factor affecting catalytic reactions. The comparative analysis of the crystal structures of axially alkylphosphane and arylphosphane ligated dirhodium(ii) acetate revealed that the shorter Rh-P bond length favors the isomerization process as compared to the longer one. In addition, the dirhodium(ii) compound can be recovered after the completion of the reaction.
Ma, Ziling,Wang, Yuanhua
supporting information
p. 7470 - 7476
(2018/10/24)

Nickel-Catalyzed Coupling of Arylzinc Halides with Thioesters
The Pd-catalyzed Fukuyama reaction of thioesters with organozinc reagents is a mild, functional-group-tolerant method for acylation chemistry. Its Ni-catalyzed variant might be a sustainable alternative to expensive catalytic Pd sources. We investigated the reaction of S-ethyl thioesters with aryl zinc halides with hetero- and homotopic Ni precatalysts and several ligands. The results show that both homo- and heterotopic species may contribute to catalysis. The substrate scope using an operationally homogeneous defined Ni complex was established. Acyl radicals are postulated as short-lived intermediates.
Gehrtz, Paul H.,Kathe, Prasad,Fleischer, Ivana
supporting information
p. 8774 - 8778
(2018/06/26)

Iron-catalyzed urea synthesis: Dehydrogenative coupling of methanol and amines
Substituted ureas have numerous applications but their synthesis typically requires the use of highly toxic starting materials. Herein we describe the first base-metal catalyst for the selective synthesis of symmetric ureas via the dehydrogenative coupling of methanol with primary amines. Using a pincer supported iron catalyst, a range of ureas was generated with isolated yields of up to 80% (corresponding to a catalytic turnover of up to 160) and with H2 as the sole byproduct. Mechanistic studies indicate a stepwise pathway beginning with methanol dehydrogenation to give formaldehyde, which is trapped by amine to afford a formamide. The formamide is then dehydrogenated to produce a transient isocyanate, which reacts with another equivalent of amine to form a urea. These mechanistic insights enabled the development of an iron-catalyzed method for the synthesis of unsymmetric ureas from amides and amines.
Lane, Elizabeth M.,Hazari, Nilay,Bernskoetter, Wesley H.
p. 4003 - 4008
(2018/05/04)

Introducing Glycerol as a Sustainable Solvent to Organolithium Chemistry: Ultrafast Chemoselective Addition of Aryllithium Reagents to Nitriles under Air and at Ambient Temperature
Edging closer towards developing air and moisture compatible polar organometallic chemistry, the chemoselective and ultrafast addition of a range of aryllithium reagents to nitriles has been accomplished by using glycerol as a solvent, at ambient temperature in the presence of air, establishing a novel sustainable access to aromatic ketones. Addition reactions occur heterogeneously (“on glycerol conditions”), where the lack of solubility of the nitriles in glycerol and the ability of the latter to form strong intermolecular hydrogen bonds seem key to favouring nucleophilic addition over competitive hydrolysis. Remarkably, PhLi exhibits a greater resistance to hydrolysis working “on glycerol” conditions than “on water”. Introducing glycerol as a new solvent in organolithium chemistry unlocks a myriad of opportunities for developing more sustainable, air and moisture tolerant main-group-metal-mediated organic synthesis.
Rodríguez-álvarez, María J.,García-álvarez, Joaquín,Uzelac, Marina,Fairley, Michael,O'Hara, Charles T.,Hevia, Eva
p. 1720 - 1725
(2018/01/27)

Transformation of Alkynes into Chiral Alcohols via TfOH-Catalyzed Hydration and Ru-Catalyzed Tandem Asymmetric Hydrogenation
A novel full atom-economic process for the transformation of alkynes into chiral alcohols by TfOH-catalyzed hydration coupled with Ru-catalyzed tandem asymmetric hydrogenation in TFE under simple conditions has been developed. A range of chiral alcohols was obtained with broad functional group tolerance, good yields, and excellent stereoselectivities.
Liu, Sensheng,Liu, Huan,Zhou, Haifeng,Liu, Qixing,Lv, Jinliang
supporting information
p. 1110 - 1113
(2018/02/23)

One-pot synthesis of chiral alcohols from alkynes by CF3SO3H/ruthenium tandem catalysis
A practical one-pot synthesis of chiral alcohols from readily available alkynes via tandem catalysis by the combination of CF3SO3H and a fluorinated chiral diamine Ru(ii) complex in aqueous CF3CH2OH is described. Very interestingly, the combination of fluorinated catalysts and solvent exhibits a positive fluorine effect on the reactivity and enantioselectivity. A range of chiral alcohols with wide functional group tolerance was obtained in high yield and excellent stereoselectivity under simple and mild conditions.
Liu, Huan,Liu, Sensheng,Zhou, Haifeng,Liu, Qixing,Wang, Chunqin
p. 14829 - 14832
(2018/04/30)

Secondary amine compound synthesized from alkyne and synthesis method of secondary amine compound
The invention relates to a secondary amine compound synthesized from alkyne and a synthesis method of the secondary amine compound. The specific structure of the compound is shown as the formula II inthe description. Meanwhile, the invention discloses the three-step one-pot synthesis method of the compound. According to the method, cheap and available acetenyl substituted benzene (I) is taken asa raw material. The method comprises steps as follows: step 1), fluorine-containing alcohol and water are taken as solvents and subjected to a hydration reaction under catalysis of trifluoromethanesulfonic acid, and an intermediate ketone is generated; step 2), aromatic amines are added directly to a reaction system, and imine is generated; step 3), tetrahydroxydiboron is added to the system, anda product II is obtained. No metal participates in the method, operation is simple and convenient, the raw materials are easily available, reaction conditions are mild, and yield is relatively high.
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Paragraph 0055; 0056; 0057

(2018/10/19)

Phosphine-Free NNN-Manganese Complex Catalyzed α-Alkylation of Ketones with Primary Alcohols and Friedl?nder Quinoline Synthesis
Herein, we report a very simple and inexpensive catalytic system based on Earth's abundant transition metal manganese and on a bench-stable phosphine-free NNN-pincer ligand for an atom-efficient α-alkylations of ketones with primary alcohols via hydrogen-autotransfer C?C bond formation protocol. The precatalyst could be generated in situ and could be activated by using catalytic amount of base under milder conditions. A range of ketones were efficiently diversified with a broad range of primary alcohols in good to excellent isolated yields. Remarkably, this catalyst could also be employed for the synthesis of quinoline derivatives using 2-aminobenzyl alcohol as an alkylating agent. The later reaction is highly benign producing only hydrogen and water as byproducts. (Figure presented.).
Barman, Milan K.,Jana, Akash,Maji, Biplab
supporting information
p. 3233 - 3238
(2018/07/31)

NNN pincer Ru(II)-complex-catalyzed α-alkylation of ketones with alcohols
A series of novel ruthenium(II) complexes supported by a symmetrical NNN ligand were prepared and fully characterized. These complexes exhibited good performance in transfer hydrogenation to form new C-C bonds using alcohols as the alkylating agents, generating water as the only byproduct. A broad range of substrates, including (hetero)aryl- or alkyl-ketones and alcohols, were well tolerated under the optimized conditions. Notably, α-substituted methylene ketones were also investigated, which afforded α-branched steric hindrance products. A potential application of α-alkylation of methylene acetone to synthesize donepezil was demonstrated, which provided the desired product in 83% yield. Finally, this catalytic system could be applied to a one-pot double alkylation procedure with sequential addition of two different alcohols. The current protocol is featured with several characteristics, including a broad substrate scope, low catalyst (0.50 mol %) loadings, and environmental benignity.
Cao, Xiao-Niu,Wan, Xiao-Min,Yang, Fa-Liu,Li, Ke,Hao, Xin-Qi,Shao, Tian,Zhu, Xinju,Song, Mao-Ping
p. 3657 - 3668
(2018/04/14)

In Water and under Mild Conditions: α-Alkylation of Ketones with Alcohols by Phase-Transfer-Assisted Borrowing Hydrogen Catalysis
Borrowing hydrogen is a powerful and green technique that allows readily available alcohols to be used as alkylating agents and produces water as the only by-product. Nevertheless, harsh conditions such as high temperatures and organic solvents are usually required. Herein, we present a strategy to perform the α-alkylation of ketones in aqueous media at mild temperatures by combining borrowing hydrogen with phase-transfer catalysis. A broad scope of methyl ketones was functionalized with alkyl and benzyl alcohols in moderate to good yields at 40 °C. The protocol was also highly effective at large scale and room temperature.
Rakers, Lena,Sch?fers, Felix,Glorius, Frank
supporting information
p. 15529 - 15532
(2018/10/09)

Tandem Cross Coupling Reaction of Alcohols for Sustainable Synthesis of β-Alkylated Secondary Alcohols and Flavan Derivatives
A Ru(II) NHC complex (loading down to 0.001 mol%) catalyzed cross coupling of a broad range of aromatic, aliphatic and heterocyclic alcohols is reported. This protocol also functioned efficiently under solvent-free conditions. Remarkably, this catalytic system disclosed so far the highest TON of 288000 for the cross coupling of alcohols. Notably, this methodology was successfully applied for the one-pot synthesis of a range of flavan derivatives. A detailed DFT studies and kinetic experiments were performed to understand the reaction mechanism as well as the high reactivity of this catalytic system. (Figure presented.).
Shee, Sujan,Paul, Bhaskar,Panja, Dibyajyoti,Roy, Bivas Chandra,Chakrabarti, Kaushik,Ganguli, Kasturi,Das, Ayan,Das, Gourab Kanti,Kundu, Sabuj
supporting information
p. 3888 - 3893
(2017/10/07)

Hydrogen autotransfer and related dehydrogenative coupling reactions using a rhenium(i) pincer catalyst
A novel rhenium complex bearing a non-innocent PNP pincer ligand was prepared. This novel catalyst is active in hydrogen autotransfer reactions to form new C-C and C-N bonds. More specifically, valuable alkylations of ketones and sulfonamides with primary alcohols are herein presented. In addition, the first examples of rhenium-catalysed synthesis of pyrroles are described by dehydrogenative coupling of diols, amines and ketones.
Piehl, Patrick,Pe?a-López, Miguel,Frey, Anna,Neumann, Helfried,Beller, Matthias
supporting information
p. 3265 - 3268
(2017/03/20)

Efficient alkylation of ketones with primary alcohols catalyzed by ruthenium(II)/P,N ligand complexes
An efficient catalytic system containing [RuCl2(η6-p-cymene)]2 and one P,N ligand, N-diphenylphosphino-2-aminopyridine (L1) was loaded in catalyzing the alkylation of ketones with primary alcohols for a diverse array of substrates. Other five P,N ligands based on pyridin-2-amine and pyrimidin-2-amine were also examined in this reaction to explore the influence of steric hindrance and electronic effects. Monitoring by 1H NMR and ESI-MS reveals a stable cationic L1-coordinated ruthenium hydride intermediate, identified as [Ru(η6-p-cymene)(κ2-L1)H]+. Organic intermediates consistent with a three-step dehydrogenation, alkylation and hydrogenation pathway were also observed. The final step in this reaction, the ruthenium-catalysed transfer hydrogenation reduction of α,β-unsaturated ketone with benzyl alcohol was performed separately.
Liu, Shi-Yuan,Xu, Lin-Yan,Liu, Chun-Yu,Ren, Zhi-Gang,Young, David James,Lang, Jian-Ping
p. 2374 - 2381
(2017/04/03)

Internal Alkyne Regio- and Chemoselectivity using a Zwitterionic N-Heterocyclic Carbene Gold Catalyst in a Silver-Free Alkyne Hydration Reaction
An alkyne hydration of terminal and internal alkynes is reported using a zwitterionic N-heterocyclic carbene gold catalyst [(BNHC)Au(SMe2)] in the absence of silver and Br?nsted acid additives. The hydration demonstrates good regioselectivity in alkyne hydration and chemoselectivity for internal alkynes vs. terminal. In addition, (BNHC)Au(SMe2) performs a propargyl alcohol hydration to predominantly form α-hydroxymethyl ketone over the more common Meyer–Schuster rearrangement product. While complex (BNHC)Au(SMe2) is active without silver additives, addition of silver hexafluoroantimonate (AgSbF6) increases reaction rate and decreases selectivity for internal alkyne hydration over terminal substrates. To the best of our knowledge, the rate enhancement of (BNHC)Au(SMe2) by AgSbF6is the first such demonstration of a silver effect for a “halide-free” Au catalyst. (Figure presented.).
Weerasiri, Kushan C.,Chen, Danmin,Wozniak, Derek I.,Dobereiner, Graham E.
p. 4106 - 4113
(2016/12/30)

Domino Methylenation/Hydrogenation of Aldehydes and Ketones by Combining Matsubara's Reagent and Wilkinson's Catalyst
The methylenation/hydrogenation cascade reaction of aldehydes or ketones through a domino process involving two ensuing steps in a single pot is realized. The compatibility of Matsubara's reagent and Wilkinson's complex give a combination that allows, under dihydrogen, the transformation of a carbonyl function into a methyl group. This new method is suitable to introduce an ethyl motif from aromatic and aliphatic aldehydes with total chemoselectivity and total retention of α-stereochemical purity. The developed procedure is also extended to the introduction of methyl groups from ketones.
Maazaoui, Radhouan,Pin-Nó, María,Gervais, Kevin,Abderrahim, Raoudha,Ferreira, Franck,Perez-Luna, Alejandro,Chemla, Fabrice,Jackowski, Olivier
supporting information
p. 5732 - 5737
(2016/12/14)

A method for synthesis of α-alkyl ketone
The invention discloses a method for synthesizing alpha-alkyl ketone. The method comprises the following steps: adding alkyne, [(IPr)AuCl], AgOTf, 1,4-dioxane and water in a reaction container, performing microwave reaction on a reaction mixture for 1h at 120 DEG C and cooling to room temperature; further adding [Cp*IrCl2]2, alkali and alcohol into the reaction mixture, performing microwave reaction on the reaction mixture for 2h at 130 DEG C and cooling to room temperature; filtering, performing rotary evaporation to remove a solvent, and then separating by a column to obtain a target compound. The method disclosed by the invention is started from chemical raw materials which are easy to obtain, namely alkyne, water and alcohol, alpha-alkyl ketone is obtained under the participation of gold and iridium catalysts, and the reaction only generates water as a byproduct. Therefore, the reaction is in line with the requirements of green chemistry and has broad development prospects.
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Paragraph 0094; 0095; 0096; 0097

(2016/11/28)

Synthesis and catalytic applications of ruthenium(ii)-phosphino-oxime complexes
In this work, the preparation of the first ruthenium complexes containing a phosphino-oxime ligand is presented. Thus, the reaction of cis-[RuCl2(DMSO)4] (3) with 2.4 equivalents of 2-Ph2PC6H4CH=NOH (1) in refluxing THF led to the clean formation of the octahedral ruthenium(ii) derivative cis,cis,trans-[RuCl2{κ2-(P,N)-2-Ph2PC6H4CH=NOH}2] (5), whose structure was unambiguously confirmed by means of a single-crystal X-ray diffraction study. Complex 5 could also be synthesized from the reaction of the dimer [{RuCl(μ-Cl)(η6-p-cymene)}2] (4) with an excess of 1 in refluxing toluene. Treatment of 4 with 2 equivalents of 1, in CH2Cl2 at r.t., allowed also the preparation of the half-sandwich Ru(ii) derivative [RuCl{κ2-(P,N)-2-Ph2PC6H4CH=NOH}(η6-p-cymene)][PF6] (6). In addition, complexes 5 and 6 proved to be active catalysts for the rearrangement of aldoximes to primary amides, as well as for the α-alkylation/reduction of acetophenones with primary alcohols, with the former showing the best performances in both processes.
Francos, Javier,Menéndez-Rodríguez, Lucía,Tomás-Mendivil, Eder,Crochet, Pascale,Cadierno, Victorio
p. 39044 - 39052
(2016/06/01)

Hydration of aromatic alkynes catalyzed by a self-assembled hexameric organic capsule
The combination of a Br?nsted acid catalyst and a supramolecular organic capsule formed by the self-assembly of six resorcin[4]arene units efficiently promotes the mild hydration of aromatic alkynes to their corresponding ketones. The capsule provides a suitable nanoenvironment that favors protonation of the substrate and addition of water.
La Sorella, Giorgio,Sperni, Laura,Ballester, Pablo,Strukul, Giorgio,Scarso, Alessandro
p. 6031 - 6036
(2016/08/05)

Bimetallic nanosized solids with acid and redox properties for catalytic activation of C-C and C-H bonds
A new approach is presented to form self-supported bimetallic nanosized solids with acid and redox catalytic properties. They are water-, air- and H2-stable, and are able to activate demanding C-C and C-H reactions. A detailed mechanistic study on the formation of the Ag-Fe bimetallic system shows that a rapid redox-coupled sequence between Ag+, O2 (air) and Fe2+ occurs, giving monodisperse Ag nanoparticles supported by O-bridged diatomic Fe3+ triflimides. The system can be expanded to Ag nanoparticles embedded within a matrix of Cu2+, Bi3+ and Yb3+ triflimide.
Cabrero-Antonino, Jose R.,Tejeda-Serrano, María,Quesada, Manuel,Vidal-Moya, Jose A.,Leyva-Pérez, Antonio,Corma, Avelino
p. 689 - 696
(2016/12/28)

Bifunctional Ru(II) complex catalysed carbon-carbon bond formation: an eco-friendly hydrogen borrowing strategy
The atom economical borrowing hydrogen methodology enables the use of alcohols as alkylating agents for selective C-C bond formation. A bifunctional 2-(2-pyridyl-2-ol)-1,10-phenanthroline (phenpy-OH) based Ru(ii) complex (2) was found to be a highly efficient catalyst for the one-pot β-alkylation of secondary alcohols with primary alcohols and double alkylation of cyclopentanol with different primary alcohols. Exploiting the metal-ligand cooperativity in complex 2, several aromatic, aliphatic and heteroatom substituted alcohols were selectively cross-coupled in high yields using significantly low catalyst loading (0.1 mol%). An outer-sphere mechanism is proposed for this system as exogenous PPh3 has no significant effect on the rate of the reaction. Notably, this is a rare one-pot strategy for β-alkylation of secondary alcohols using a bifunctional Ru(ii)-complex. Moreover, this atom-economical methodology displayed the highest cumulative turn over frequency (TOF) among all the reported transition metal complexes in cross coupling of alcohols.
Chakrabarti, Kaushik,Paul, Bhaskar,Maji, Milan,Roy, Bivas Chandra,Shee, Sujan,Kundu, Sabuj
p. 10988 - 10997
(2016/12/06)

Bifunctional RuII-Complex-Catalysed Tandem C?C Bond Formation: Efficient and Atom Economical Strategy for the Utilisation of Alcohols as Alkylating Agents
Catalytic activities of a series of functional bipyridine-based RuIIcomplexes in β-alkylation of secondary alcohols using primary alcohols were investigated. Bifunctional RuIIcomplex (3 a) bearing 6,6’-dihydroxy-2,2’-bipyridine (6DHBP) ligand exhibited the highest catalytic activity for this reaction. Using significantly lower catalyst loading (0.1 mol %) dehydrogenative carbon?carbon bond formation between numerous aromatic, aliphatic and heteroatom substituted alcohols were achieved with high selectivity. Notably, for the synthesis of β-alkylated secondary alcohols this protocol is a rare one-pot strategy using a metal–ligand cooperative RuIIsystem. Remarkably, complex 3 a demonstrated the highest reactivity compared to all the reported transition metal complexes in this reaction.
Roy, Bivas Chandra,Chakrabarti, Kaushik,Shee, Sujan,Paul, Subhadeep,Kundu, Sabuj
supporting information
p. 18147 - 18155
(2016/12/16)

Method for synthesizing alpha-alkyl ketone
The invention discloses a method for synthesizing alpha-alkyl ketone. The method comprises the following steps: adding ketone, a compound alcohol, an iridium complex catalyst, an alkali and a solvent tert-amyl alcohol in a reaction container, carrying out a refluxing reaction on the above obtained reaction mixture in air for several hours, cooling the obtained reaction product to room temperature, carrying out rotary evaporation to remove the solvent, and carrying out column separation to obtain the target compound. The meta-organic bifunctional iridium complex is used, only 0.1 equivalent carbonate is added in the reaction process, and the reaction is carried in air for 6h, so obvious advantages are displayed; and the reaction accords with green chemistry requirements, and has wide development prospect.
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Paragraph 0095; 0096; 0097; 0098; 0099

(2016/10/07)

Manganese-Catalyzed Hydrogen-Autotransfer C?C Bond Formation: α-Alkylation of Ketones with Primary Alcohols
A novel catalytic hydrogen-autotransfer protocol for the atom-efficient α-alkylation of ketones with readily available alcohols is presented. The use of manganese complexes bearing non-innocent PNP pincer ligands enabled the functionalization of a broad range of valuable ketones, including 2-oxindole, estrone 3-methyl ether, and testosterone. Mechanistic investigations suggest the participation of an intramolecular amidate-assisted alcohol-dehydrogenation process.
Pe?a-López, Miguel,Piehl, Patrick,Elangovan, Saravanakumar,Neumann, Helfried,Beller, Matthias
supporting information
p. 14967 - 14971
(2016/11/25)

Benzyltin pyrimidine derivatives, their preparation and their use as medicaments
The invention relates to the field of pharmaceutical chemistry, specifically to benzyl pyrimidine derivatives (I), preparation methods thereof, medicinal compositions containing the derivatives and medical application of the derivatives, in particular, application of the derivatives as an immunosuppressant in autoimmune diseases and organ transplantation.
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Paragraph 0086; 0087

(2017/01/19)

Palladium catalyzed decarboxylative acylation of arylboronic acid with ethyl cyanoacetate as a new acylating agent: Synthesis of alkyl aryl ketones
Palladium catalyzed acylation of arylboronic acid containing various functional groups was performed efficiently by ethyl cyanoacetate/substituted ethyl cyanoacetate as the acylating agent in aqueous triflic acid medium. The alkyl aryl ketones were obtained in good to excellent yields, first by addition of arylboronic acid to the nitrile group of ethyl cyanoacetate and their derivatives, followed by in situ decarboxylation of the resulting β-ketoester.
Yousuf, Md,Das, Tuluma,Adhikari, Susanta
p. 8763 - 8770
(2015/11/10)

Iron-Catalyzed α-Alkylation of Ketones with Alcohols
A general and benign iron-catalyzed α-alkylation reaction of ketones with primary alcohols has been developed. The key to success of the reaction is the use of a Kn?lker-type complex as catalyst (2 mol %) in the presence of Cs2CO3 as base (10 mol %) under hydrogen-borrowing conditions. Using 2-aminobenzyl alcohol as alkylation reagent allows for the "green" synthesis of quinoline derivatives.
Elangovan, Saravanakumar,Sortais, Jean-Baptiste,Beller, Matthias,Darcel, Christophe
supporting information
p. 14483 - 14486
(2016/01/25)

Allylic and benzylic sp3 C-H oxidation in water
A copper-catalyzed method for the oxidation of allylic and benzylic sp3 C-H by aqueous tert-butyl hydroperoxide (T-Hydro) in water using a recyclable fluorous ligand has been developed. The reaction procedure is tolerant to additional functional groups and the fluorous ligand could be reused with little loss of catalytic activity. This journal is
Ang, Wei Jie,Lam, Yulin
p. 1048 - 1052
(2015/03/04)

Fluorous bispidine: A bifunctional reagent for copper-catalyzed oxidation and knoevenagel condensation reactions in water
Fluorous bispidine-type ligands have been developed to facilitate its recovery and reusability and to demonstrate its bifunctional property as a ligand and base in copper-catalyzed aerobic oxidation, the Knoevenagel condensation and tandem oxidation/Knoevenagel condensation in water under mild conditions. Application of the fluorous ligand was also extended to the surfactant-free copper-catalyzed allylic and benzylic sp3 C-H oxidation reaction in water. The fluorous ligands could be recovered using F-SPE with recovery ranging from 91-97% and could be reused five times with little loss of activity.
Ang, Wei Jie,Chng, Yong Sheng,Lam, Yulin
p. 81415 - 81428
(2015/10/06)

Palladium complexes of heterobidentate ligands: Active catalysts for direct acylation of aryl halides with aldehydes via C(sp2)-H activation
Abstract Heterobidentate P-S donor ligands [P-S = {2-(methylthio) phenyl}diphenylphosphine (a) and {2-((methylthio) methyl) phenyl}diphenylphosphine (b)], and their palladium complexes of the type [Pdη2-(P-S)Cl2] (1a, 1b) have been synthesised and characterised. Single crystal X-ray diffraction shows that in both the complexes, Pd occupies the centre of a slightly distorted square planar geometry. 1a forms a planner ring structure, whereas, the hexagonal ring of 1b bends from planarity to adjust any ring strain. Interesting differences between the complexes were observed in terms of the intermolecular forces. The catalytic activities of the synthesised complexes towards the direct acylation of aryl halides with aldehydes via C(sp2)-H activation were good to excellent. 1b shows better catalytic activity over 1a which may be attributed to the higher stability of the pentagonal ring of 1a. Aryl halides containing electron withdrawing group enhance the reaction, while electron donating substituent tend to retard the desired product formation. The difference in the bond lengths of Pd-P and Pd-S of the chelate complexes may impart hemilabile behaviour in the catalytic cycle by dissociating the weaker bond (Pd-S) to generate vacant coordination site at the metal centre and reassociate after the completion of the reaction.
Saikia, Kokil,Dutta, Dipak Kumar
p. 20 - 25
(2015/08/04)