- Aromatic substituent effects in palladium-catalyzed intramolecular olefin oxyarylation reactions
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The effect of electron-donating groups on the palladium-catalyzed intramolecular oxyarylation reaction was studied. In the case of activation at the ortho-position, the reaction favors the formation of a tricyclic lactone via C–H insertion. However, when
- Brenzovich, W. E.,Croft, Zacary L.,Dove, Ross L.,Hardy, Emily E.,Maust, Mark C.,Sullivan, Mackenzie W.
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- Iodoarene-Catalyzed Oxyamination of Unactivated Alkenes to Synthesize 5-Imino-2-Tetrahydrofuranyl Methanamine Derivatives
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Reported here is the room-temperature metal-free iodoarene-catalyzed oxyamination of unactivated alkenes. In this process, the alkenes are difunctionalized by the oxygen atom of the amide group and the nitrogen in an exogenous HNTs2 molecule. This mild and open-air reaction provided an efficient synthesis to N-bistosyl-substituted 5-imino-2-tetrahydrofuranyl methanamine derivatives, which are important motifs in drug development and biological studies. Mechanistic study based on experiments and density functional theory calculations showed that this transformation proceeds via activation of the substrate alkene by an in situ generated cationic iodonium(III) intermediate, which is subsequently attacked by an oxygen atom (instead of nitrogen) of amides to form a five-membered ring intermediate. Finally, this intermediate undergoes an SN2 reaction by NTs2 as the nucleophile to give the oxygen and nitrogen difunctionalized 5-imino-2-tetrahydrofuranyl methanamine product. An asymmetric variant of the present alkene oxyamination using chiral iodoarenes as catalysts also gave promising results for some of the substrates.
- Deng, Xiao-Jun,Liu, Hui-Xia,Zhang, Lu-Wen,Zhang, Guan-Yu,Yu, Zhi-Xiang,He, Wei
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p. 235 - 253
(2021/01/09)
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- mCPBA-mediated dioxygenation of unactivated alkenes for the synthesis of 5-imino-2-tetrahydrofuranyl methanol derivatives
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A mCPBA-mediated, metal-free, intramolecular dioxygenation reaction of unactivated alkenes is reported. In the presence of m-chlorobenzoic peracid, different unsaturated amide substrates could be cyclized via epoxide intermediates, producing the corresponding 5-imino-2-tetrahydrofuranyl methanol products in up to 94% yield at room temperature.
- Deng, Xiaojun,Zhang, Luwen,Liu, Huixia,Bai, Yu,He, Wei
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- Preparation of cyclic imides from alkene-tethered amides: Application of homogeneous Cu(ii) catalytic systems
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A Cu-based homogeneous catalytic system was proposed for the preparation of imides from alkene-tethered amides. Here, O2 acted as a terminal oxidant and a cheap and easily available oxygen source. The cleavage of CC bonds and the formation of C
- Chen, Suqing,Liu, Zhenghui,Mu, Tiancheng,Ou, Hualin,Tan, Xingxing,Wang, Peng,Yan, Zhenzhong,Yu, Dongkun,Zhao, Xinhui
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p. 7698 - 7707
(2020/03/13)
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- Copper(II)-Catalyzed Alkene Aminosulfonylation with Sodium Sulfinates for the Synthesis of Sulfonylated Pyrrolidones
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A copper-catalyzed direct aminosulfonylation of unactivated alkenes with sodium sulfinates for the efficient synthesis of sulfonylated pyrrolidones is described. This reaction features good functional group tolerance and wide substrate scope, providing an efficient and straightforward protocol to access this kind of pyrrolidones. Moreover, preliminary mechanistic investigations disclosed that a free-radical pathway might be invovled in the process.
- Rao, Wei-Hao,Jiang, Li-Li,Liu, Xiao-Meng,Chen, Mei-Jun,Chen, Fang-Yuan,Jiang, Xin,Zhao, Jin-Xiao,Zou, Guo-Dong,Zhou, Yu-Qiang,Tang, Lin
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supporting information
p. 2890 - 2893
(2019/04/30)
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- Niobium-Catalyzed Intramolecular Addition of O-H and N-H Bonds to Alkenes: A Tool for Hydrofunctionalization
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A convenient, versatile, and easy to handle intramolecular hydrofunctionalization of alkenes (C-O and C-N bonds formation) is reported using a novel niobium-based catalytic system. This atom economic and eco-friendly methodology provides an additional synthetic tool for the straightforward formation of valuable building blocks enabling molecular complexity. Various pyran, furan, pyrrolidine, piperidine, lactone, and lactam derivatives as well as spirocyclic compounds are produced in high yields and selectivities.
- Ferrand, Laura,Tang, Yue,Aubert, Corinne,Fensterbank, Louis,Mouriès-Mansuy, Virginie,Petit, Marc,Amatore, Muriel
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supporting information
p. 2062 - 2065
(2017/04/28)
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- Iridium-Catalyzed Intramolecular Oxidative Cyclization of Alkenyl Amides and Alkenoic Acids
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An iridium/dppf complex efficiently catalyzed the oxidative cyclization of N sulfonyl alkenyl amides and alkenoic acids. Electron deficiena?t alkenes were effective as sacrificial hydrogen acceptors. High selectivity of the oxidative cyclization over the
- Nagamoto, Midori,Nishimura, Takahiro,Yorimitsu, Hideki
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p. 4272 - 4282
(2017/09/13)
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- Direct oxidative lactonization of alkenoic acids mediated solely by NaIO4: Beyond a simple oxidant
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Triflic acid-catalyzed direct oxidative lactonization of alkenoic acids mediated solely by NaIO4 without halogen salts is described. Sodium periodate works not only as an oxidant, but also as an active reagent and directly mediates the lactonization. A new cheap, green, and practical oxidative lactonization approach has been developed using NaIO4 as the sole reagent.
- Kang, Yan-Biao,Chen, Xian-Min,Yao, Chuan-Zhi,Ning, Xiao-Shan
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supporting information
p. 6193 - 6196
(2016/05/19)
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- NOVEL SIGMA-2 RECEPTOR BINDERS AND THEIR METHOD OF USE
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Pharmaceutical compositions of the invention comprise functionalized lactone derivatives having a disease-modifying action in the treatment of diseases associated with dysregulation of sigma-2 receptor activity.
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Paragraph 0292
(2016/11/28)
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- CuX2-mediated oxybromination/aminochlorination of unsaturated amides: Synthesis of iminolactones and lactams
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We report herein a CuX2-mediated halocyclization of γ,δ-unsaturated amides for the synthesis of functionalized iminolactones and lactams respectively under mild reaction conditions. Mechanism studies indicated that N-attack cyclization was via a radical route while oxycyclization was via a nucleophilic attack on the activated CC bond.
- Zhang, Zhi-Qiang,Liu, Feng
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supporting information
p. 6690 - 6693
(2015/06/25)
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- NOVEL 5-HYDROXYTRYPTAMINE RECEPTOR 7 ACTIVITY MODULATORS AND THEIR METHOD OF USE
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Pharmaceiiticai compositions of the invention comprise functionalized lactone derivatives having a disease-modifying action in the treatment of diseases associated with dysregulation of 5-hydroxytryptamine receptor 7 activity.
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Paragraph 0255
(2014/10/18)
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- Regioselective silver-mediated Kondakov-Darzens olefin acylation
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Enone construction: A silver-mediated olefin acylation reaction is described, in which five-, six-, and -seven-membered rings, tetrasubstituted olefins, bridged bicycles, spirocycles, and benzoxepinones are prepared. Highly selective intermolecular reactions are coupled to a Nazarov cyclization for the effective preparation of cyclopentenones, including the core of modhephene (see scheme). Copyright
- Barczak, Nicholas T.,Jarvo, Elizabeth R.
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supporting information; experimental part
p. 12912 - 12916
(2011/12/04)
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- Acyloxylactonisations mediated by lead tetracarboxylates
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The reaction of lead(IV) tetracarboxylates with carboxylic acids containing unsaturated side chains has been found to give acyloxy lactone products in a diastereoselective process; the reaction can be extended to lead(IV) tetrazolates to give the analogous outcome. Mechanistic implications of these results are discussed.
- Cottrell, Ian F.,Cowley, Andrew R.,Croft, Laura J.,Hymns, Lauren,Moloney, Mark G.,Nettleton, Ewan J.,Kirsty Smithies,Thompson, Amber L.
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supporting information; experimental part
p. 2537 - 2550
(2009/08/07)
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- Dirhodium(II) tetrakis[N-tetrafluorophthaloyl-(S)-tert-leucinate]: An exceptionally effective Rh(II) catalyst for enantiotopically selective aromatic C-H insertions of diazo ketoesters
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Dirhodium(II) tetrakis[N-tetrafluorophthaloyl-(S)-tert-leucinate], Rh2[(S)-TFPTTL]4, in which the phthalimido hydrogen atoms of the parent dirhodium(II) complex are substituted by fluorine atoms, dramatically enhances the reactivity and enantioselectivity (up to 97% ee) in intramolecular aromatic C-H insertion reactions of methyl 4-alkyl-2-diazo-4,4-diphenyl-3-oxopropionates. Catalysis with the use of 0.001 mol% of Rh2[(S)-TFPTTL]4 has achieved the highest turnover number (up to 98,000 with the methyl substituent) ever recorded for chiral dirhodium(II) complex-catalyzed carbene transformations, without compromising the yield or enantioselectivity of the process.
- Tsutsui, Hideyuki,Yamaguchi, Yukiko,Kitagaki, Shinji,Nakamura, Seiichi,Anada, Masahiro,Hashimoto, Shunichi
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p. 817 - 821
(2007/10/03)
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- Transition-metal catalyzed synthesis of δ-hydroxy-γ-lactones from bis(trimethylsilyl) ketene acetals and allylic acetates via γ-unsaturated carboxylic acids. Comments on the formation of α-cyclopropyl carboxylic acids
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Bis(trimethylsilyl)ketene acetals react with allylic acetates in the presence of Pd(0) complexes to give γ-unsaturated carboxylic acids together with α-cyclopropyl carboxylic acids. The unsaturated acids can be converted catalytically to δ-hydroxy-yγ-lactones by the H2O2/MTO system (methyltrioxorhenium) and to butenolides by Pd(II) catalyzed intramolecular cyclization reactions. The structure of two of these lactones has been established by X-ray analysis. The mechanism of the formation of the cyclopropanic acids will be discussed.
- Rudler, Henri,Harris, Paul,Parlier, Andrée,Cantagrel, Frédéric,Denise, Bernard,Bellassoued, Moncef,Vaissermann, Jacqueline
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p. 186 - 202
(2007/10/03)
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- 5-(1-(IMIDAZOL)METHYL)-3,3-DISUBSTITUTED-2(3H)FURANONE DERIVATIVES
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Furanone compounds and compositions having anticholinergic activity are described. The compounds have the formula: STR1 wherein: the dashed line indicates either the 4,5-unsaturated or the 4,5-dihydrofuranone ring;R 1 and R 2 may be the same or different and are hydrogen, thienyl, furanyl, or cycloalkyl (C. sub.3-C 6), benzyl, phenyl, substituted phenyl or substituted benzyl wherein the phenyl or benzyl group may be substituted with halogen, trifluoromethyl, lower alkyl, lower alkoxy or hydroxy;R. sub.3, R 4 and R 5 may be the same or different and are hydrogen, lower alkyl, lower alkyl substituted with a halogen, alkoxy, amino or carboxylic acid group, an alkyl or alkylene bridge between R 4 and R. sub.5 or R 3 and the ring N, trifluoromethyl, nitro, a cycloalkyl group containing 3 to 6 carbons, halogen, benzyl, phenyl, substituted phenyl or substituted benzyl, for which the substituents are the same as those set forth for R 1 and R 2 substituted benzyl or phenyl.R 6 in the dihydrofuranone series is hydrogen or lower alkyl.Also described are the pharmaceutically acceptable quaternary alkyl and acid addition salts of such compounds. The compounds are particularly useful in the treatment of neurogenic bladder disorder and chronic obstructive pulmonary diseases.
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- Diastereoselectivity in the reduction of sterically unbiased 2,2-diarylcyclopentanones
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Reduction of sterically unbiased 2-phenyl-2-(4-X-phenyl)cyclopentanones 1 (X = NO2, Br, Cl, OCH3, OH, NH2) with either sodium borohydride in methanol or lithium borohydride in tetrahydrofuran at 0°C produced diastereomeric
- Halterman, Ronald L.,McEvoy, Marjorie A.
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p. 6690 - 6695
(2007/10/02)
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- Effects of α-Substitution on the Rate of Chloromercuriolactonization of Phenyl Esters of γδ-Unsaturated Acids
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Second-order rate constants for the reaction of several phenyl esters of α-alkyl- and/or α-aryl-substituted allyacetic acids with mercury(II) chloride have been determined in 50percent aqueous ethanol.It was found that α-substitution increases the rate of reaction.The rate constants can be correlated with the dual substituent parameter expressions (i) and (ii).In the systems studied the steric coefficient is much larger than the polar one, suggesting that the effect of the substituents on the rate of the reaction is essentially steric in nature, with a small additional contribution from the polar effect. log k2 = log k2o + ρ*?* + δEs (i). log k2 = log k2o + ρ*?* + ψν (ii)
- de Almeida, Maria I.,do Amaral, Antonia T.,do Amaral, Luciano
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p. 1953 - 1958
(2007/10/02)
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- Effects of α Substitution on the Carbonyl Stretching Frequencies of Phenyl Carboxylates
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The infrared carbonyl stretching frequencies for several esters of the general formula R1R2R3C-COOPh were determined in carbon tetrachloride.The ?* and Es Taft parameters as well as the νCharton parameters for the same esters were determined.The carbonyl stretching frequencies are well correlated by a dual substituent parameter treatment: νC=O = νC=O0 + ρ*?* + δES or νC=O = νC=O0 + ρ*?* + ΨνCharton.In both cases the steric parameter is much larger than the polar parameter, suggesting that the effect of the substituents on the carbonyl stretching frequencies is of a steric nature, although a small contribution of the polar effect is observed.
- Almeida, Maria Ines de,Amaral, Antonia T. do,Amaral, Luciano do
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p. 1567 - 1571
(2007/10/02)
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- An Efficient and General Synthesis of 5-Substituted Pyrrolidinones
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2-Pyrrolidinone derivatives are widespread materials of considerable laboratory and commercial importance.In spite of this, there is no generally useful synthesis of either symmetrically or unsymmetrically 5,5-disubstituted derivatives.This is particularl
- Miller, R. D.,Goelitz, P.
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p. 1616 - 1618
(2007/10/02)
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