- Nickel-Catalyzed Desymmetrizing Cyclization of 1,6-Dienes to Construct Quaternary Stereocenters
-
A highly enantioselective and diastereoselective nickel-catalyzed desymmetrizing cyclization of 1,6-dienes was developed by using chiral spiro phosphoramidite ligands. The reaction provides a new atom- and step-economical approach to chiral spiro lactones and analogues bearing a quaternary stereocenter.
- Zhao, Tian-Yuan,Li, Ke,Yang, Liang-Liang,Zhu, Shou-Fei,Zhou, Qi-Lin
-
supporting information
p. 3814 - 3817
(2021/05/26)
-
- Visible Light-Promoted Magnesium, Iron, and Nickel Catalysis Enabling C(sp3)-H Lactonization of 2-Alkylbenzoic Acids
-
A mild and practical C(sp3)-H lactonization protocol has been achieved by merging photocatalysis and magnesium (iron, nickel) catalysis. A diverse range of 2-alkylbenzoic acids with a variety of substitution patterns could be transformed into the corresponding phthalide products. Based on the mechanistic experimentation and reported prior studies, a possible mechanism for the benzylic oxidative lactonization reaction was proposed with the hypothetic photoactive ternary complex formed between the 2-alkylbenzoic acid substrate, magnesium ion, and bromate anion.
- Li, Sasa,Su, Mincong,Sun, Jie,Hu, Kunjun,Jin, Jian
-
supporting information
p. 5842 - 5847
(2021/07/31)
-
- Green Oxidation of Ketones to Lactones with Oxone in Water
-
Cyclic ketones were quickly and quantitatively converted to 5-, 6-, and 7-membered lactones, very important synthons, by treatment with Oxone, a cheap, stable, and nonpollutant oxidizing reagent, in 1 M NaH2PO4/Na2HPO4 water solution (pH 7). Under such simple and green conditions, no hydroxyacid was formed, thus making the adoption of more complex and non-eco-friendly procedures previously developed to avoid lactone hydrolysis unnecessary. With some changes, the method was successfully applied also to water-insoluble ketones such as adamantanone, acetophenone, 2-indanone, and the challenging cycloheptanone.
- Bertolini, Valentina,Appiani, Rebecca,Pallavicini, Marco,Bolchi, Cristiano
-
p. 15712 - 15716
(2021/11/01)
-
- Synthesis method of 3-isochromanone
-
The invention belongs to the technical field of synthesis of organic intermediates, and particularly relates to a synthesis method of 3-isochromanone, which comprises the following steps of: (1) synthesizing o-methyl benzyl chloride by using o-xylene as a raw material; (2) synthesizing o-methyl benzyl cyanide by taking o-methyl benzyl chloride as a raw material; (3) synthesizing sodium o-methyl phenylacetate by taking o-methyl benzyl cyanide as a raw material; (4) synthesizing o-methyl phenylacetic acid by taking sodium o-methyl phenylacetate as a raw material; (5) synthesizing 2-chloromethylphenylacetic acid by taking o-methyl phenylacetic acid as a raw material; and (6) synthesizing 3-isochromanone by taking 2-chloromethyl phenylacetic acid as a raw material. The synthesis method of 3-isochromanone has the advantages of simple reaction process, easily available raw materials, mild reaction conditions, high product yield, low production cost, high yield, high product purity, good quality, low production waste discharge amount and the like, the product purity is greater than or equal to 99.5%, the production yield is greater than or equal to 92%, and the product meets the use requirements of foreign high-end users.
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-
-
- Regioselective biocatalytic self-sufficient Tishchenko-type reactionviaformal intramolecular hydride transfer
-
A self-sufficient nicotinamide-dependent intramolecular bio-Tishchenko-type reaction was developed. The reaction is catalyzed by alcohol dehydrogenases and proceeds through formal intramolecular hydride transfer on dialdehydes to deliver lactones. Regioselectivity on [1,1′-biphenyl]-2,2′-dicarbaldehyde substrates could be controlledviathe electronic properties of the substituents. Preparative scale synthesis provided access to substituted dibenzo[c,e]oxepin-5(7H)-ones.
- Buljubasic, Isa,Hall, Mélanie,Laggner, Olivia,Merusic, Kemal,Reiter, Tamara,Tassano, Erika,Vogel, Andreas
-
p. 6340 - 6343
(2020/06/21)
-
- (Cyclopentadienone)iron-Catalyzed Transfer Dehydrogenation of Symmetrical and Unsymmetrical Diols to Lactones
-
Air-stable iron carbonyl compounds bearing cyclopentadienone ligands with varying substitution were explored as catalysts in dehydrogenative diol lactonization reactions using acetone as both the solvent and hydrogen acceptor. Two catalysts with trimethylsilyl groups in the 2- A nd 5-positions, [2,5-(SiMe3)2-3,4-(CH2)4(δ4-C4C= O)]Fe(CO)3 (1) and [2,5-(SiMe3)2-3,4-(CH2)3(δ4-C4C= O)]Fe(CO)3 (2), were found to be the most active, with 2 being the most selective in the lactonization of diols containing both primary and secondary alcohols. Lactones containing five-, six-, and seven-membered rings were successfully synthesized, and no over-oxidations to carboxylic acids were detected. The lactonization of unsymmetrical diols containing two primary alcohols occurred with catalyst 1, but selectivity was low based on alcohol electronics and modest based on alcohol sterics. Evidence for a transfer dehydrogenation mechanism was found, and insight into the origin of selectivity in the lactonization of 1°/2° diols was obtained. Additionally, spectroscopic evidence for a trimethylamine-ligated iron species formed in solution during the reaction was discovered.
- Tang, Yidan,Meador, Rowan I. L.,Malinchak, Casina T.,Harrison, Emily E.,McCaskey, Kimberly A.,Hempel, Melanie C.,Funk, Timothy W.
-
p. 1823 - 1834
(2020/02/04)
-
- 3 - Isochromanone micro-channel synthesis method (by machine translation)
-
The invention discloses a 3 - isochromanone micro-channel synthesis method, the reaction steps are as follows: 1) to O-methyl acetic acid as the raw material, under an appropriate temperature and in a suitable solvent, using microchannel reaction technology, in order to chloride is a chlorination reagent to prepare the O-methyl acetic acid; 2) synthesis of O-methyl acetic acid without purification, in the appropriate alkali and temperature, cyclization reaction to obtain 3 - isochromanone. Through the above-mentioned way, the invention can be high-yield, high-purity, controllable production of O-methyl acetic acid, while the latter can be smoothly under alkaline conditions to produce the target product 3 - isochromanone. (by machine translation)
- -
-
Paragraph 0026-0035
(2019/03/28)
-
- Platinum-on-Carbon-Catalyzed Aqueous Oxidative Lactonization of Diols by Using Molecular Oxygen
-
A lactonization of various diols catalyzed by platinum on carbon (Pt/C) in water under an atmosphere of molecular oxygen was developed. Derivatives of 1,4- 1,5- and 1,6-diols were transformed into the corresponding five-, six-, and seven-membered lactones by the present oxidative lactonization method.
- Ban, Kazuho,Sajiki, Hironao,Sawama, Yoshinari,Takakura, Ryoya
-
supporting information
p. 1919 - 1923
(2019/09/30)
-
- A General, Activator-Free Palladium-Catalyzed Synthesis of Arylacetic and Benzoic Acids from Formic Acid
-
A new catalyst for the carboxylative synthesis of arylacetic and benzoic acids using formic acid (HCOOH) as the CO surrogate was developed. In an improvement over previous work, CO is generated in situ without the need for any additional activators. Key to success was the use of a specific system consisting of palladium acetate and 1,2-bis((tert-butyl(2-pyridinyl)phosphinyl)methyl)benzene. The generality of this method is demonstrated by the synthesis of more than 30 carboxylic acids, including non-steroidal anti-inflammatory drugs (NSAIDs), under mild conditions in good yields.
- Wang, Lin,Neumann, Helfried,Beller, Matthias
-
supporting information
p. 6910 - 6914
(2018/06/04)
-
- COMPOUNDS FROM RENEWABLE RESOURCES
-
Compounds of formula III: and salts thereof are disclosed. Also disclosed are methods for preparing compounds of formula III, intermediates useful for preparing compounds of formula III and methods for preparing compounds and materials from compounds of formula III.
- -
-
Paragraph 0289-0292
(2017/10/26)
-
- A 3 - different chromone preparation method
-
The invention discloses a method for preparing 3-isochromanone. The method includes the steps that organic solvent is added into o-tolylacetic acid to be heated to 50-60 DEG C, phosphorus oxychloride is added while stirring is conducted, reacting continues till the o-tolylacetic acid disappears, and reacting is stopped; then the organic solvent is cooled, washed and dried, and accordingly the 3-isochromanone is obtained. According to the method, the technology is relatively simple, the raw materials can be obtained easily, and cost is low. Moreover, the quantity of three wastes is small, the content and yield of target products are high, and the method is suitable for industrial production.
- -
-
Paragraph 0019-0033
(2017/08/17)
-
- Polymerization of epoxide with hydroxylamides as thermally latent initiators
-
A new class of thermally latent initiators for the ring-opening polymerization of epoxides has been developed. The latent initiators developed herein were the hydroxylamides 1a, 1b, and 1c, which were synthesized from phthalide, 3-isochromanone, and cis-cyclohexahydrophthalide, respectively, by their ring-opening reactions with pyrrolidine. These hydroxylamides were designed so that their hydroxyl groups could attack the amide moiety intramolecularly upon heating, leading to ring closure and formation of the corresponding lactones while releasing pyrrolidine, the initiator for the anionic ring-opening polymerization of an epoxide. The temperatures at which this thermal dissociation occurred were strongly dependent on the hydroxylamide molecular structure. When using the hydroxylamides as thermally latent initiators, the polymerizations of bisphenol-A diglycidyl ether were investigated at various temperatures. This investigation clarified that the threshold temperature, that is, the temperature at which polymerization was initiated, increased in the order of 1a, 1b, and then 1c.
- Wang, Yanmei,Kimura, Mika,Sudo, Atsushi,Endo, Takeshi
-
p. 2611 - 2617
(2016/07/14)
-
- Iron(II) pincer-catalyzed synthesis of lactones and lactams through a versatile dehydrogenative domino sequence
-
The synthesis of lactones and lactams by using iron(II) pincer-catalyzed dehydrogenative methodology was developed. Starting from 1,n-diols or 1,n-amino alcohols, this domino transformation takes place through initial dehydrogenation of the substrates, subsequent intramolecular cyclization, and final oxidation to afford the desired products in good yields. The ability to access heterocycles of different sizes makes this protocol especially versatile, in which two consecutive oxidation reactions are performed without requiring an external oxidant. In this paper, we report the application of the Fe-MACHO-BH complex [carbonylhydrido(tetrahydroborato)[bis(2-diisopropylphosphinoethyl)amino]iron(II)] in this atom-efficient and environmentally benign process, for which molecular hydrogen is formed as the only stoichiometric side product. Just a little pinch: The iron(II) pincer-catalyzed synthesis of lactones and lactams from easily available 1,n-diols and 1,n-amino alcohols is explored. The use of a nontoxic metal as well as the generation of molecular hydrogen as the only stoichiometric byproduct makes this method a highly atom-efficient and environmentally benign process.
- Pea-Lpez, Miguel,Neumann, Helfried,Beller, Matthias
-
p. 865 - 871
(2015/03/14)
-
- Efficient and Selective Cu/Nitroxyl-Catalyzed Methods for Aerobic Oxidative Lactonization of Diols
-
Cu/nitroxyl catalysts have been identified that promote highly efficient and selective aerobic oxidative lactonization of diols under mild reaction conditions using ambient air as the oxidant. The chemo- and regioselectivity of the reaction may be tuned by changing the identity of the nitroxyl cocatalyst. A Cu/ABNO catalyst system (ABNO = 9-azabicyclo[3.3.1]nonan-N-oxyl) shows excellent reactivity with symmetrical diols and hindered unsymmetrical diols, whereas a Cu/TEMPO catalyst system (TEMPO = 2,2,6,6-tetramethyl-1-piperidinyl-N-oxyl) displays excellent chemo- and regioselectivity for the oxidation of less hindered unsymmetrical diols. These catalyst systems are compatible with all classes of alcohols (benzylic, allylic, aliphatic), mediate efficient lactonization of 1,4-, 1,5-, and some 1,6-diols, and tolerate diverse functional groups, including alkenes, heterocycles, and other heteroatom-containing groups.
- Xie, Xiaomin,Stahl, Shannon S.
-
supporting information
p. 3767 - 3770
(2015/04/14)
-
- Hypervalent iodine catalyzed cyclization of aryl-substituted alkanoic acids
-
A novel and efficient procedure was developed for direct preparation of aryl-substituted lactones from corresponding aryl-substituted alkanoic acids, catalyzed by the in situ generated hypervalent iodine intermediate from iodobenzene (PhI). In this protocol, aryl-substituted alkanoic acids were treated with m-chloroperbenzoic acid (mCPBA) and KBr in the presence of a catalytic amount of PhI in 2,2,2-trifluoroethanol at room temperature for 24 h, resulting in corresponding aryl lactones in moderate-to-good yields. Copyright
- Li, Tingting,Xiang, Changbin,Zhang, Bijun,Yan, Jie
-
p. 854 - 860
(2014/07/07)
-
- Ammonium iodide-promoted cyclization of aryl-substituted carboxylic acids
-
An efficient procedure was developed for direct preparation of aryl-substituted lactones from corresponding aryl carboxylic acids, which was promoted by ammonium iodide. In this protocol, aryl carboxylic acids were treated with ammonium iodide, potassium bromide, and oxidant Oxone in a mixture of acetonitrile and 2,2,2-trifluoroethanol (6:4) at room temperature for 12 h, resulting in corresponding aryl lactones in moderate to good yields.
- Zhang, Bijun,Han, Liuquan,Li, Tingting,Yan, Jie,Yang, Zhenping
-
supporting information
p. 1608 - 1613
(2014/06/09)
-
- Dehydrogenative lactonization of diols in aqueous media catalyzed by a water-soluble iridium complex bearing a functional bipyridine ligand
-
A new catalytic system for the dehydrogenative lactonization of a variety of benzylic and aliphatic diols in aqueous media was developed. By using a water-soluble, dicationic iridium catalyst bearing 6,6′-dihydroxy-2, 2′-bipyridine as a functional ligand, highly atom economical and environmentally benign synthesis of various lactones was achieved in good to excellent yields. Recovery and reuse of the catalyst were also accomplished by a simple phase separation and the recovered catalyst maintained its high activity at least until the fifth run. Copyright
- Fujita, Ken-Ichi,Ito, Wataru,Yamaguchi, Ryohei
-
p. 109 - 112
(2014/01/23)
-
- Hydroruthenation triggered catalytic conversion of dialdehydes and keto aldehydes to lactones
-
Lactonization of dialdehydes and keto aldehydes was effectively catalyzed by RuHCl(CO)(PPh3)3. A cascade lactonization sequence accompanied by cross-coupling with enones was also attained.
- Omura, Sohei,Fukuyama, Takahide,Murakami, Yuji,Okamoto, Hiromi,Ryu, Ilhyong
-
supporting information; experimental part
p. 6741 - 6743
(2010/03/25)
-
- Enzymatic Baeyer-Villiger oxidation of Benzo-Fused ketones: Formation of regiocomplementary lactones
-
Baeyer-Villiger monooxygenases (BVMOs) are enzymes that are known to catalyse the Baeyer-Villiger oxidation of ketones in aqueous media using O2 as oxidant. Herein, we describe the oxidation of a set of diverse benzo-fused ketones by three different BVMOs
- Rioz-Martinez, Ana,De Gonzalo,Torres Pazmino, Daniel E.,Fraaije, Marco W.,Gotor, Vicente
-
experimental part
p. 2526 - 2532
(2009/09/25)
-
- PROCESS FOR PREPARING 3-ISOCHROMANONE
-
A process for the preparation of 3-isochromanone which comprises contacting an o-xylene-alpha,alpha'-dihalide with carbon monoxide, in the presence of a catalyst and a hindered amine base in a liquid medium comprising water and a tertiary alcohol.
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Page/Page column 7
(2008/06/13)
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- Studies of reactions of o-xylylene-α,α′-dihalides with palladium complexes and the catalytic synthesis of 3-isochromanone
-
Homogeneous catalysis by palladium complexes with phosphorus(III) ligands of the carbonylation of o-xylylene dihalides in the presence of water to form 3-isochromanone has been studied. Triphenylphosphine was found to provide the most effective catalyst, and by-products and intermediates of systems containing this ligand have been investigated. 2-Indanone is one by-product but is unstable to decomposition under catalytic conditions. Excess PPh3 is necessary to prolong activity of the catalyst but is also transformed to bis-phosphonium compound [o-C6H4(CH2PPh3)2]X2 (X = Cl or Br); this quaternization has been investigated and the structure of the bromide salt determined by X-ray diffraction. An unstable oxidative addition product of Pd(PPh3)4 was detected as a probable intermediate and related to the previously reported but catalytically-inactive complex trans-Pd(o-CH2C6H4CH2Cl)Cl(PMe3)2, which has been structurally characterized by X-ray diffraction in this work.
- Jones, Ray V.H.,Lindsell, W. Edward,Paddon-Jones, Greg C.,Palmer, Daniel D.,Preston, Peter N.,Rosair, Georgina M.,Whitton, Alan J.
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p. 2378 - 2385
(2007/10/03)
-
- PALLADACYLES, THEIR PREPARATION AND CATALYTIC PROCESSES INVOLVING THEIR USE AS CATALYST, ESPECIALLY CATALYTIC CARBONYLATION PROCESSES
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The present invention relates to palladium compounds and their use as catalysts for improved catalytic processes. Specifically there is disclosed an improved catalytic carbonylation process and improved carbonylation catalysts. Catalysts in dimer form are also disclosed, as is their catalytic activity and methods of making the compounds.
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Page/Page column 27-28
(2008/06/13)
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- Synthesis and structure activity relationships of novel non-peptidic metallo-aminopeptidase inhibitors
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Racemic derivatives of 3-amino-2-tetralone were synthesised and evaluated for their ability to inhibit metallo-aminopeptidase activities. New compounds substituted in position 2 by methyl ketone, substituted oximes or hydroxamic acids as well as heterocyclic derivatives were evaluated against representative members of zinc-dependent aminopeptidases: leucine aminopeptidase (E.C. 3.4.11.1), aminopeptidase-N (E.C. 3.4.11.2), Aeromonas proteolytica aminopeptidase (E.C. 3.4.11.10), and the aminopeptidase activity of leukotriene A4 hydrolase (E.C. 3.3.2.6). Several compounds showed Ki values in the low micromolar range against the 'one-zinc' aminopeptidases, while most of them were rather poor inhibitors of the 'two-zinc' enzymes. This interesting selectivity profile may guide the design of new, specific inhibitors of target mammalian aminopeptidases with one active site zinc.
- Albrecht, Sebastien,Defoin, Albert,Salomon, Emmanuel,Tarnus, Celine,Wetterholm, Anders,Haeggstroem, Jasper Z.
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p. 7241 - 7257
(2007/10/03)
-
- Synthesis of γ- and δ-lactones from alkynols
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The reaction of alkynyl phenyl selenides with p-toluene-sulfonic acid gives rise to a proton-induced ring-closure reaction affording γ- and δ-lactones. Georg Thieme Verlag Stuttgart.
- Tiecco, Marcello,Testaferri, Lorenzo,Temperini, Andrea,Terlizzi, Raffaella,Bagnoli, Luana,Marini, Francesca,Santi, Claudio
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p. 587 - 590
(2007/10/03)
-
- CHEMICAL PROCESS
-
3-Isochromanone is prepared by partially chlorinating o-tolylacetic acid with sulphuryl chloride or chlorine gas in an inert organic solvent in the presence of a free radical initiator. The 2-chloromethylphenylacetic acid first obtained is converted to 3-isochromanone by treatment with a base and separated from unreacted o-tolylacetic acid, which is in the form of a salt, by a phase separation technique. The separated o-tolylacetic acid salt is converted to o-tolylacetic acid by controlled acidification and the o-tolylacetic acid is extracted for re-use. The invention reduces the formation of unwanted, over-chlorinated by-products and leads to a more efficient process.
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Page/Page column 6
(2008/06/13)
-
- Syntheses and biological evaluation of vinblastine congeners.
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Sixty-two congeners of vinblastine (VLB), primarily with modifications of the piperidine ring in the carbomethoxycleavamine moiety of the binary alkaloid, were synthesized and evaluated for cytotoxicity against murine L1210 leukemia and RCC-2 rat colon cancer cells, and for their ability to inhibit polymerization of microtubular protein at 10(7) M concentrations was found for L1210 inhibition by these compounds, with the most active 1000x as potent as vinblastine.
- Kuehne, Martin E,Bornmann, William G,Marko, Istvan,Qin, Yong,LeBoulluec, Karen L,Frasier, Deborah A,Xu, Feng,Mulamba, Tshilundu,Ensinger, Carol L,Borman, Linda S,Huot, Anne E,Exon, Christopher,Bizzarro, Fred T,Cheung, Julia B,Bane, Susan L
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p. 2120 - 2136
(2007/10/03)
-
- Process for the preparation of isochroman-3-ones
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The present invention relates to a process for the preparation of an isochroman-3-one of the formula (I) by reaction of a 1,2-bishalomethylbenzene of the formula (II) in which X is chlorine, bromine or iodine, with carbon monoxide and a compound of the formula (III) R5R6R7C—OH??(III) at a CO pressure of 0.1 to 50 MPa and a temperature of 20 to 200° C. in the presence or absence of an ionic halide, in the presence of a palladium catalyst and of a dipolar aprotic solvent, with addition of water or without addition of water, where in the formulae (I) and (II) the radicals R1, R2, R3and R4independently of one another are: a hydrogen or fluorine atom; an NC or F3C group; an alkyl, alkoxy or acyloxy radical, in each case having 1 to 18 carbon atoms; or a C6-C18-aryloxy, aryl or heteroaryl radical, where 1 to 3 atoms from the group consisting of O, N and/or S are present as heteroatoms; or in which at least two of the radicals R1, R2, R3and R4are linked to one another and form at least one aliphatic or aromatic ring having 5 to 18 carbon atoms, and in formula (III) the radicals R5, R6and R7are identical or different and are a C1-C18-alkyl, an HOC(═O)—, H3CC(═O)CH2— or (C6-C18-aryl)-CH2— radical or at least two of the radicals R5, R6and R7are linked to one another and form at least one aliphatic or aromatic ring having 5 to 18 carbon atoms.
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-
Page column 7
(2008/06/13)
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- Process for preparing 3-isochromanone
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A process for the preparation of 3-isochromanone which comprises contacting an o-xylene-α,α′-dihalide with carbon monoxide, in the presence of a catalyst and a hindered amine base in a liquid medium comprising water and a tertiary alcohol.
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-
-
- Process for producing isochromanones and intermediates thereof
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(1) Methods for producing isochromanone compounds from o-xylene compounds as starting compounds through α-halogeno-o-xylene derivatives, α-cyano-o-xylene derivatives, and α-halogeno-α′-cyano-o-xylene derivatives, and (2) methods for producing isochromanone compounds from o-xylene compounds as starting compounds through α,α′-dihalogeno-o-xylene derivatives, α,α′-dihydroxy-o-xylene derivatives, α-halogeno-α′-hydroxy-o-xylene derivatives and α-cyano-α′-hydroxy-o-xylene derivatives, and methods for producing these intermediate compounds.
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- Facile and Clean Oxidation of Alcohols in Water Using Hypervalent Iodine (III) Reagents
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The facile and efficient oxidation of various alcohols such as benzylic alcohols, primary alcohols, secondary alcohols, and diols in water using the hypervalent iodine(III) reagent, iodosobenzene (PhI=O), with KBr is described. Electrospray ionization (ESI) mass spectrometric studies on the behavior of PhI=O-KBr in aqueous solution suggested that these reactions are induced by the formation of highly reactive iodine species [PhI(Br)nO-]. Further development to recyclable polymer-supported iodine(III) reagent extends the utility of this reaction to afford an environmentally benign method.
- Tohma, Hirofumi,Maegawa, Tomohiro,Takizawa, Shinobu,Kita, Yasuyuki
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p. 328 - 337
(2007/10/03)
-
- Method for manufacturing 3-isochromanone
-
The present invention intends to provide a method for producing 3-isochromanones represented by formula (II) useful as a synthetic starting material of medicals or agricultural chemicals and the cyano compound represented by formula (I) by an industrially advantageous method in a high yield.Disclosed herein is a method for manufacturing a 3-isochromanone represented by the following formula (II): (wherein R2, R3, R4 and R5 each independently represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group),said method is characterized by comprising the steps of:hydrolyzing a cyano compound represented by formula (I): (wherein R1 represents a hydrogen atom, an alkyl group or an aryl group, and R2, R3, R4 and R5 have the same meanings as defined above) and subjecting the hydrolyzate to intra-molecular cyclization.
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- Process for preparing 3-isochromanone
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3-Isochromanome is prepared by reacting an o-xylene-α,α′-dihalide with carbon monoxide and water in the presence of a metal catalyst such that the pH of the reaction is maintained between about 7 and 11.
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-
-
- Process for preparing isochroman-3-ones
-
The present invention relates to a process for preparing an isochroman-3-one of the formula (I) by reacting a 1,2-bishalomethylbenzene of the formula (II) in which X is chlorine, bromine or iodine with carbon monoxide and water at a CO pressure of from 0.1 to 50 MPa and a temperature of from 20 to 200 DEG C. in the presence or absence of an ionic halide, in the presence of a palladium catalyst and a dipolar aprotic solvent, where in the formulae (I) and (II) the radicals R1, R2, R3 and R4 independently of one another denote: a hydrogen or fluorine atom; a HO2CCH=CH-, NC- or F3C group; an alkyl, alkoxy or acyloxy radical having in each case 1 to 18 carbon atoms; or a C6-C18-aryloxy, aryl or heteroaryl radical, where the heteroatoms present are 1 to 3 atoms from the group O, N and/or S; a R52P(=O)-, R6C(=O)-, R6OC(=O)-, R6OC(=O)CH=CH-, R7C(=O)-, R7OC(=O)CH=CH- or R72P(=O) radical; in which R5 is a C1-C4-alkyl radical, R6 is a C1-C18-alkyl radical and R7 is a C6-C18-aryl radical; or in which at least one of the radicals R1, R2, R3 and R4 is substituted by a radical R8, where R8 has the same meaning as R1; or where at least two of the radicals R1, R2, R3 and R4 are linked with one another and form at least one aliphatic or aromatic ring having 5 to 18 carbon atoms.
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-
-
- Process for producing 2-(halomethyl)phenylacetic acid esters
-
2-(Halomethyl)phenylacetic acid esters (3) which are useful as intermediates for producing agricultural fungicides are produced efficiently and conveniently by reacting a 3-isochromanone derivative (1) with a hydrogen halide and an alcohol or reacting (1) with a halomethyl alkyl ether and then reacting the product with an alcohol in the presence of a base. The starting compound, 3-isochromanone (1), is produced in good yield by reacting an α,α'-o-xylene dihalide (4) with carbon monoxide and water in an organic solvent in the presence of a palladium catalyst and an inorganic base and then treating the product with an acid. STR1
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-
- Process for the catalytic preparation of 3-isochromanones from phthalans
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Good yields and selectivities are achieved in a process for preparing an isochroman-3-one of the formula (I) STR1 by reacting a 1,3-dihydroisobenzofuran of the formula (II) STR2 with carbon monoxide at a CO pressure of from 0.1 to 20 MPa in the presence of an ionic halide, a palladium catalyst and a dipolar aprotic solvent.
- -
-
-
- Process for preparing 3-isochromanone
-
3-Isochromanone is prepared by reacting o-tolyacetic acid with sulphuryl chloride in the presence of a free radical initiator, e.g. AIBN, followed by ring closure of the 2-chloromethylphenylacetic acid so formed with a base, e.g. potassium bicarbonate.
- -
-
-
- Direct Carbonylation of Benzyl Alcohol and Its Analogs Catalyzed by Palladium and HI in Aqueous Systems and Mechanistic Studies
-
Carbonylation of benzyl alcohol, benzyl formate, dibenzyl ether, and benzyl phenylacetate catalyzed by palladium complexes and promoted by hydrogen iodide gives phenylacetic acid in moderate to excellent yields in aqueous systems. Application of the carbonylation process to other arylmethanol analogs provides convenient means to prepare 2-naphthaleneacetic acid, 3-isochromanone, 1,4-benzenediacetic acid, and o-hydroxybenzeneacetic acid. A mechanism for the catalytic reaction is proposed, which involves (1) formation of benzyl iodide by the reaction of benzyl alcohol with HI in situ, (2) oxidative addition of benzyl iodide to palladium(0) to form a benzylpalladium iodide species. (3) CO insertion into the Pd-benzyl bond to form a (phenylacetyl)palladium iodide species. (4) reductive elimination of phenylacetyl iodide, and (5) its hydrolysis into phenylacetic acid. Evidence supporting the mechanism was obtained by examining the properties of benzyl- and (phenylacetyl)palladium iodide and chloride complexes. Formation of benzyl(carbonyl)palladium species and migratory insertion of the benzyl group to CO was confirmed by means of NMR at low temperature under high pressure.
- Lin, Yong-Shou,Yamamoto, Akio
-
p. 723 - 734
(2007/10/03)
-
- Palladium-catalyzed carbonylation of benzyl alcohol and its analogs promoted by HI in aqueous systems
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Carbonylation of benzyl alcohol catalyzed by a palladium(0) complex and promoted by hydrogen iodide gives phenylacetic acid in excellent yields in aqueous systems. The catalysis is proposed to proceed through a benzylpalladium species formed by the oxidative addition of benzyl iodide, produced in situ by the interaction of benzyl alcohol with HI, to a Pd(0) species. Application of the carbonylation process to other arylmethanol analogs provided convenient means to prepare 3-isochromanone, 1,4-benzenediacetic acid, 2-hydroxybenzeneacetic acid and 2-naphthaleneacetic acid.
- Lin, Yong-Shou,Yamamoto, Akio
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p. 3747 - 3750
(2007/10/03)
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- Electron-transfer-induced reductive cleavage of phthalans: Reactivity and synthetic applications
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The behavior of phthalan (1a) was investigated under conditions of electron transfer from alkali metals in aprotic solvents. Reaction with lithium in the presence of a catalytic amount of naphthalene in THF led to the reductive cleavage of an arylmethyl carbon-oxygen bond, with formation of a stable dilithium compound. Trapping of this intermediate with several electrophiles (alkyl halides, carbonyl derivatives, CO2) was successful. The extension of this procedure to several substituted phthalans (1b-i) was investigated, and the regiochemistry as well as the synthetic usefulness of these reactions are discussed.
- Azzena, Ugo,Demartis, Salvatore,Melloni, Giovanni
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p. 4913 - 4919
(2007/10/03)
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- Diastereoselective alkylation of homochiral 1,2,3,4-tetrahydroisoquinolin-3-one. A potential route to enantiomerically pure 4-substituted tetrahydroisoquinolines
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Enantiomerically pure 1,4-dihydroisoquinolin-3-one 1 was prepared in four steps with an overall yield of 60%. Alkylation of the corresponding lactam enolate has been studied and has proven to be highly diastereoselective. Thus, 4-substituted-1,4-dihydroisoquinolin-3-ones 7a-d were obtained in high chemical yields with up to 97% diastereoisomeric excesses.
- Philippe, Nicolas,Levacher, Vincent,Dupas, Georges,Duflos, Jack,Queguiner, Guy,Bourguignon, Jean
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p. 417 - 420
(2007/10/03)
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- 1,2-Di(lithiomethyl)benzene from Phthalan: Sequential Introduction of Two Different Electrophiles
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The reaction of phthalan (1) with an excess of lithium powder and a catalytic amount of DTBB (2.5 mol percent) in THF at 20 deg C followed by treatment with electrophiles (D2O, CO2 and carbonyl compounds) at -78 deg C leads, after hydrolysis, to the corresponding functionalised benzylic alcohols 3a-g.When the lithiation reaction is continued, after the reaction with the first electrophile, and a second electrophile (H2O, D2O and carbonyl compounds) is added, the corresponding disubstituted compounds 6a-q are prepared.Diols 3c-g and 6h,i,l,n and hydroxyacids 6a,c,f,k are easily dehydrated to the corresponding cyclic ethers (7c-f, 8h,i,l,n) or lactones (9a,c,f,k) respectively.Finally, alcohols 6b,d,e give, after acid treatment, the Friedel-Crafts type benzocyclopentenes 10b,d,e.
- Almena, Juan,Foubelo, Francisco,Yus, Miguel
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p. 3351 - 3364
(2007/10/02)
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- Reductive electrophilic substitution of phthalans and ring expansion to isochroman derivatives
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Reductive cleavage of phthalan, 1a, with Li metal in the presence of a catalytic amount of naphthalene leads to the formation of a stable aromatic dilithium compound. The adducts of the latter with CO2, aldehydes or ketones undergo ring closure to isochroman derivatives, leading to ring expansion of the original heterocycle. The reductive electrophilic substitution procedure was successfully extended to the substituted phthalans 1b and 1c, to afford the corresponding isochroman-3-ones in satisfactory yields.
- Azzena, Ugo,Demartis, Salvatore,Fiori, Maria Giovanna,Melloni, Giovanni,Pisano, Luisa
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p. 8123 - 8126
(2007/10/02)
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- Synthetic approaches to 2-substituted 1-oxo- and 3-oxotetrahydroisoquinolines
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2-Substituted homophthalimides 2a-c were reduced regioselectively with sodium borohydride to carbinol-lactam intermediates 3a-c, which were dehydrated, followed by hydrogenation, to give 1-oxotetrahydroisoquinolines or 3,4-dihydroisoquinolin-1(2H)ones 5a-c. The isomeric 3-oxo-tetrahydroisoquinolines or 1,4-dihydroisoquinolin-3(2H)-ones 8a-i were obtained in satisfactory yields via heating 3-isochromanone (6) with the corresponding amines 7a-i in the presence of aluminum chloride.
- Cheng,Tsai,Lin
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- Torquoselectivity in the electrocyclic conversion of benzocyclobutenes to o-xylylenes
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The conrotatory electrocyclic opening of benzocyclobutene to o-xylylene was studied by means of ab initio molecular orbital calculations. The theory developed earlier to predict the torquoselectivity of ring opening of 3-substituted cyclobutenes was found to be applicable. Experimentally, the ring opening of several 7-substituted benzocyclobutenes, such as the cyano, methoxycarbonyl, and formyl derivatives was examined. o-Xylylenes were obtained in which cyano or ester groups had rotated outwards, whereas the formyl group turned inwards. N,N-Dimethylbenzocyclobutene-7-carboxamide exhibited 75% inward torquoselectivity upon ring opening. A reversal of mode was seen with the 7-methyl derivatives of benzocyclobutene-7-carbonitrile and methyl benzocyclobutene-7-carboxylate in that the 7-methyl substituent manifested overwhelming outward motion.
- Jefford, Charles W.,Bernardinelli, Gerald,Wang, Ying,Spellmeyer, David C.,Buda, Andrzej,Houk
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p. 1157 - 1165
(2007/10/02)
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- Baeyer-Villiger oxidation of ketones to esters with sodium percarbonate/trifluoroacetic acid
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Sodium percarbonate in trifluoroacetic acid has been found to be an effective reagent for the Baeyer-Villiger oxidation of ketones to esters. The scope and limitations of the reaction were explored.
- Olah,Wang,Trivedi,Surya Prakash
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p. 739 - 740
(2007/10/02)
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- Novel alkaloids
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Cycloalkyl and aromatic vinblastine and vincristine derivatives useful as anti-tumor agents.
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- MODIFIED CONDITIONS FOR EFFICIENT BAEYER-VILLIGER OXIDATION WITH m-CPBA
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The utility of 3-chloroperoxybenzoic acid (m-CPBA) combined with trifluoroacetic acid (TFA) in Baeyer-Villiger oxidations is described.These conditions offer practical advantages over alternative procedures.
- Koch, Stacie S. Canan,Chamberlin, A. Richard
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p. 829 - 834
(2007/10/02)
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- New Syntheses of Isochromene
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Isochromene is easily prepared in three steps either from the homophthalic acid (Route A) or from the 2-indanone (Route B).The synthetic Route B gives a better yield.
- Cottet, F.,Cottier, L.,Descotes, G.
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p. 497 - 498
(2007/10/02)
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- A Convenient Total Synthesis of (+/-)-Bharatamine and (+/-)-Isobharatamine
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N,N-Dimethylbenzylamine (1) on lithiation with n-butyllithium followed by reaction with paraformaldehyde gives the 2-hydroxymethyl derivative (2). 2 on successive reactions with ClCOOEt, KCN and alc.KOH followed by cyclisation furnishes isochroman-3-one (3).Condensation of 3 with phenylethylamines (4a) and (4b), followed by cyclisation (PCl5), reduction (NaBH4), and debenzylation (EtOH-HCl) gives (+/-)-bharatamine (6c) and (+/-)-3-hydroxy-4-methoxy-5,6,13,13a-tetrahydro-8H-dibenzoquinolizine (isobharatamine, 6d), respectively in high yields.
- Patil, Sharadbala D.,Mali, R. S.
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p. 360 - 362
(2007/10/02)
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