- Synthesis of novel benzochromenes using triarylphosphines, alkyl X-phenylpropiolates and 2-hydroxy-1-naphthaldehyde
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The reactions of a series of alkyl X-phenylpropiolates with 2-hydroxy-1-naphthaldehyde and triphenylphosphine led to benzochromenes in moderate yields. When the reactions were performed in the presence of bis(4-methoxyphenyl)phenylphosphine instead of tri
- Gholami, Hamid Reza,Asghari, Sakineh
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- Gold-catalyzed partial hydrogenation of activated alkynes mediated by triphenylphosphine
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Gold(I) can exhibit a cooperative effect with triphenylphosphine, accelerating the triphenylphosphine-mediated partial hydrogenation of activated alkynes. In this protocol, 3-arylpropiolates are selectively reduced to the Z -isomer when the aryl ring bears an electron-donor substituent, whereas 3-arylpropynones are reduced to the E-isomers.
- Cocoletzi-Xochitiotzi, Ana Patricia,Hernández-Hernández, Miguel,Medina-Mercado, Ignacio,Jiménez-Martínez, Williams De Jesús,Mastranzo, Virginia Maricela,Porcel, Susana
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supporting information
p. 2379 - 2386
(2020/08/19)
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- Consecutive Three-Component Coupling-Addition Synthesis of β-Amino Enoates and 3-Hydroxypyrazoles via Ethyl 3-Arylpropiolates
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Two consecutive three-component syntheses furnishing β-amino enoates or 3-hydroxypyrazoles based upon the Sonogashira alkynylation of aryl iodides and ethyl propiolate were established in mostly excellent yields. The ethyl 3-arylpropiolate intermediates are Michael systems which are suited for concatenation with conjugate addition or cyclocondensation giving access to libraries of 21 different β-amino enoates and 17 different 3-hydroxypyrazoles. The rotational barrier of β-pyrrolidino enoates was assessed by studying the coalescence of pyrrolidinyl protons in VT-NMR spectra of electronically different substituted derivatives showing that the electronic substituent effect on the aryl group does not affect the height of the rotational barrier. This indicates that the substituents are essentially oriented orthogonally to the plane of the β-pyrrolidino enoates.
- Niedballa, Jonas,Reiss, Guido J.,Müller, Thomas J. J.
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supporting information
p. 5019 - 5024
(2020/07/24)
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- Metal-Free Oxidative [5+1] Cyclization of 1,5-Enynes for the Synthesis of Pyrazine 1-Oxide
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A chemo-selective nitrosylation of 1,5-enynes via a sequence of NO radical incorporation and intramolecular radical cyclization was reported. The formation of two C?N bonds and one C?O bond make this [5+1] cycloaddition reaction an efficient approach to synthesize pyrazine 1-oxides in moderate to good yields. Metal-free, short reaction time and mild conditions render this strategy more practical, eco-friendly and convenient. Synthetic utility of this protocol is highlighted by scaffolds diversification. (Figure presented.).
- Xia, Xiao-Feng,Zhao, Mingming,He, Wei,Zou, Lianghua,San, Xinxin,Wang, Dawei
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supporting information
p. 3621 - 3626
(2020/08/05)
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- Rhodium-catalyzed enantioselective decarboxylative alkynylation of allenes with arylpropiolic acids
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A rhodium-catalyzed chemo-, regio-, and enantioselective intermolecular decarboxylative alkynylation of terminal allenes with arylpropiolic acids is reported. Employing a Rh(I)/(R)-Tol-BINAP catalytic system, branched allylic 1,4-enynes were obtained under mild conditions. The overall utility of this protocol is exemplified by a broad functional group compatibility.
- Grugel, Christian P.,Breit, Bernhard
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supporting information
p. 1066 - 1069
(2018/02/23)
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- A Parallel Approach to 7-(Hetero)arylpyrazolo[1,5- a]pyrimidin-5-ones
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A modular, two-pot assembly of 7-arylpyrazolo[1,5-a]pyrimidones from aryl/heteroaryl halides and aminopyrazoles in library format was developed. Sonogashira coupling of aryl bromides with triethyl orthopropiolate, followed by in situ orthoester hydrolysis
- Schmitt, Daniel C.,Niljianskul, Nootaree,Sach, Neal W.,Trujillo, John I.
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supporting information
p. 256 - 260
(2018/05/24)
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- Phosphine-mediated partial reduction of alkynes to form both (E)- and (Z)-alkenes
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A mild, phosphine-mediated partial reduction of alkynyl carbonyls to the corresponding alkenes was developed. Tuning of the reaction conditions led to either the (E)- or (Z)-diastereomer with high selectivity. A range of alkynyl esters, amides, and ketones were reduced to form alkenes in good to high yields and with excellent functional group tolerance.
- Pierce, Brett M.,Simpson, Brittany F.,Ferguson, Kane H.,Whittaker, Rachel E.
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supporting information
p. 6659 - 6662
(2018/09/29)
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- Gold(I)/Chiral N,N′-Dioxide–Nickel(II) Relay Catalysis for Asymmetric Tandem Intermolecular Hydroalkoxylation/Claisen Rearrangement
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A highly efficient asymmetric cascade reaction between alkynyl esters and allylic alcohols has been realized. Key to success was the combination of a hydroalkoxylation reaction catalyzed by a π-acidic gold(I) complex with a Claisen rearrangement catalyzed by a chiral Lewis acidic N,N′-dioxide–nickel(II) complex. A range of acyclic α-allyl β-keto esters were synthesized in high yields (up to 99 %) with good diastereoselectivities (up to 97:3) and excellent enantioselectivities (up to 99 % ee) under mild reaction conditions. These products can be easily transformed into optically active β-hydroxy esters, β-hydroxy acids, or 1,3-diols.
- Li, Jun,Lin, Lili,Hu, Bowen,Zhou, Pengfei,Huang, Tianyu,Liu, Xiaohua,Feng, Xiaoming
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supporting information
p. 885 - 888
(2017/01/13)
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- Gold-catalyzed Fluorination of Alkynyl Esters and Ketones: Efficient Access to Fluorinated 1,3-Dicarbonyl Compounds
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We developed an efficient synthesis of 2-fluoro-1,3-dicarbonyl compounds using readily available alkynyl ketones or esters as starting material. The key step is the insertion of hydrogen fluoride (HF) to the gold carbene intermediate generated from cationic gold catalyzed addition of N-oxides to alkynyl ketones or esters. This method gives excellent chemical yields and regioselectivity with good functional group tolerance. (Figure presented.).
- Zeng, Xiaojun,Lu, Zhichao,Liu, Shiwen,Hammond, Gerald B.,Xu, Bo
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supporting information
p. 4062 - 4066
(2017/11/30)
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- Enantioselective Palladium-Catalyzed Oxidative Cascade Cyclization of Aliphatic Alkenyl Amides
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The catalyst system of Pd(TFA)2/(S,S)-diPh-pyrox is reported to promote the highly efficient enantioselective oxidative cascade cyclization of alkene-tethered aliphatic acrylamides under mild aerobic conditions. A series of pyrrolizidine derivatives have been synthesized in good yield and excellent enantioselectivity. Deuterium-labeling experiments have revealed that the reaction proceeded through an anti-aminopalladation (anti-AP) pathway with high selectivity. The transition states for the anti-AP step have been calculated to account for the observed enantioselectivity.
- Du, Wei,Gu, Qiangshuai,Li, Yang,Lin, Zhenyang,Yang, Dan
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supporting information
p. 316 - 319
(2017/04/21)
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- Visible-Light-Promoted Vinylation of Tetrahydrofuran with Alkynes through Direct C-H Bond Functionalization
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(Chemical Equation Presented) Mild and direct C-H bond functionalizations and vinylations of tetrahydrofuran with alkynes have been accomplished through visible light photocatalysis, yielding a range of vinyl tetrahydrofurans under the synergistic actions of organic dye-type photocatalyst eosin Y, tert-butyl hydroperoxide (t-BuOOH), and a 45 W household lightbulb. A significant kinetic isotope effect (KIE) was recorded, which helps shed light on the mechanistic course.
- Li, Jing,Zhang, Jing,Tan, Haibo,Wang, David Zhigang
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supporting information
p. 2522 - 2525
(2015/05/27)
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- Copper(i)/phosphine-catalyzed tandem carboxylation/annulation of terminal alkynes under ambient pressure of CO2: One-pot access to 3a-hydroxyisoxazolo[3,2-a]isoindol-8(3aH)-ones
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An efficient method for the synthesis of 3a-hydroxyisoxazolo[3,2-a]isoindol-8(3aH)-ones from CO2, terminal alkynes, EtBr, and NHPI (N-hydroxyphthalimide) was developed through a tandem carboxylation/annulation strategy catalyzed by a copper(i)/phosphine system. This one-pot multicomponent reaction was conducted at atmospheric CO2 pressure to afford the target products in good to excellent yields under mild conditions. Notably, a wide range of functional groups were tolerated in this procedure. This protocol with simultaneous formation of four novel bonds i.e. two C-C bonds and two C-O bonds represents an efficient methodology for upgrading CO2 into heterocycles.
- Xie, Jia-Ning,Yu, Bing,Guo, Chun-Xiang,He, Liang-Nian
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p. 4061 - 4067
(2015/07/15)
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- Gold catalysis coupled with visible light stimulation: Syntheses of functionalized indoles
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A judicious combination of Au-catalysis and synergistic visible-light stimulation formulates an exceptionally simple and mild reaction system capable of directly coupling anilines and alkynes to form multifunctionalized indoles.
- Cai, Shunyou,Yang, Kai,Wang, David Zhigang
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supporting information
p. 2606 - 2609
(2014/06/09)
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- Gold-catalyzed 1,2-iminonitronation of electron-deficient alkynes with nitrosoarenes to afford α-imidoyl nitrones
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Gold-catalyzed 1,2-iminonitronation of propiolate derivatives with nitrosoarenes to give α-imidoyl nitrones is described; this new reaction is applicable to diverse propiolate derivatives and nitrosoarenes.
- Singh, Rahulkumar Rajmani,Liu, Rai-Shung
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p. 15864 - 15866
(2015/01/08)
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- Investigation of quantitative structure-reactivity relationships in the aliphatic Claisen rearrangement of bis-vinyl ethers reveals a dipolar, dissociative mechanism
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Kinetic investigations of substituent effects in the thermal rearrangement of bis-vinyl ether substrates are reported. Findings indicate that the influence of the various substituent patterns on the rate of rearrangement in these compounds differs from that documented in the literature for the analogous [3,3]-sigmatropic rearrangement of allyl vinyl ethers. In addition, the thermochemical data collected suggests the existence of a dissociative transition state with significant dipolar character. These findings provide a unique contribution to the already extensive body of literature dedicated to mechanistic investigation of the Claisen rearrangement of aliphatic allyl vinyl ethers.
- O'Rourke, Natasha F.,Wulff, Jeremy E.
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p. 1292 - 1308
(2014/03/21)
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- A convenient regioselective synthesis of cyclopentadienones via palladium-catalyzed [2+2+1] cyclocarbonylation of alkynes
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A simple and efficient synthesis of cyclopentadienones via palladium-catalyzed cyclocarbonylation of alkynes under atmospheric pressure of carbon monoxide has been developed. The transformation was carried out under mild and ligand-free conditions, a wide range of substrates and exceptional functional group tolerance.
- Xu, Yanli,Zhao, Jinwu,Chen, Huoji,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 2488 - 2490
(2014/03/21)
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- Synthesis of fluorenone and anthraquinone derivatives from aryl- and aroyl-substituted propiolates
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Fluorenone derivatives were generated from aryl-substituted propiolates via a cobalt-catalyzed Diels-Alder reaction/DDQ-oxidation and Friedel-Crafts-type cyclization. Several functional groups are tolerated, and good to excellent overall yields (up to 89%) could be achieved. For the synthesis of anthraquinone derivatives, aroyl-substituted propiolates were applied in a zinc iodide catalyzed Diels-Alder reaction with 1,3-dienes. The subsequent DDQ oxidation and Friedel-Crafts-type cyclization led to symmetrical as well as some unsymmetrical anthraquinones in good to excellent yields of up to 87% over the three-step reaction sequence.
- Puenner, Florian,Schieven, Justin,Hilt, Gerhard
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supporting information
p. 4888 - 4891
(2013/10/08)
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- Preparation of arylpropynamides and their reaction with malonyl acid derivatives
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Synthesis of arylpropynamides and their reactions with different malonic acid derivatives is described. Treatment of arylpropynamides with unsubstituted malonyl chloride furnished N-(3-arylprop-2-ynoyl)-6-chloro-4-hydroxy-2-oxo-2H- pyran-3-carboxamides; m
- Petina, Olgaa. A.,Yakovlev, Igorp. P.,Geffken, Detlef
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p. 803 - 809
(2013/04/10)
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- COMPOUNDS
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The present invention features compounds of formula (I): and salts thereof, pharmaceutical compositions comprising said compounds, and uses of such compounds in treating or preventing viral infections, such as HCV infections, and diseases associated with such infections.
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- CuII-exchanged montmorillonite K10 clay-catalyzed direct carboxylation of terminal alkynes with carbon dioxide
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A new, simple and straight-forward protocol for direct carboxylation of terminal alkynes has been developed using CuII-montmorillonite K10 clay as a heterogeneous catalyst and CO2 as the C1 carbon feedstock. Also coupling of terminal alkynes with CO2 (1 atm) in the presence of alkyl halides has been achieved under the same reaction conditions, thereby providing access to a variety of functionalized alkyl-2-alkynoates in high yields.
- Aher, Ravindra D.,Gade, Madhuri H.,Reddy, R. Santhosh,Sudalai, Arumugam
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p. 1325 - 1329,5
(2020/08/31)
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- PYRROLIDINE DERIVATIVES
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The present invention relates to compounds of formula wherein R1, R2, R3, R4, Z, and n are as defined herein or to a pharmaceutically active salt thereof. Compounds of the invention are high potential NK-3 receptor antagonists for the treatment of depression, pain, psychosis, Parkinson's disease, schizophrenia, anxiety and attention deficit hyperactivity disorder (ADHD).
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Page/Page column 45-46
(2011/06/25)
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- PYRROLIDINE DERIVATIVES
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The present invention relates to compounds of formula (I) or to a pharmaceutically active salt thereof. It has been found that the present compounds are high potential NK-3 receptor antagonists for the treatment of depression, pain, psychosis, Parkinson's
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Page/Page column 91-92
(2011/08/04)
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- Pd2+ and Cu2+ catalyzed oxidative cross-coupling of mercaptoacetylenes and arylboronic acids
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An oxidative thiolate scavenging concept in a metal catalyzed reaction is presented and demonstrated on the aerobic Pd and Cu catalyzed cross-coupling of mercaptoacetylenes with arylboronic acids. Synthetic value of the chemistry as the complementary tool to the Sonogashira protocol has been demonstrated on a series of functionalized mercaptoacetylene substrates.
- Henke, Adam,Srogl, Jiri
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p. 4282 - 4284
(2011/06/21)
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- PROCESS FOR THE PREPARATION OF PYROLLIDINE-3-CARBOXYLIC ACIDS
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The invention relates to a novel process for the preparation of (3S,4S)- or (3R,4R)-1-benzyl-4-(halogen-aryl)-pyrrolidine-3-carboxylic acids of formula I or salts thereof, wherein X and Y are each independently hydrogen or a halogen atom, with the proviso that at least one of X or Y is a halogen atom. The compounds of formula I are useful as starting materials or intermediates for the preparation of pharmaceutically active compounds, especially for compounds, which are useful for the treatment of central nervous system disorders.
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(2010/06/22)
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- Ligand-free copper(Ι)-catalyzed Sonogashira-type coupling of arylboronic acids with terminal alkynes
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An efficient ligand-free CuI-catalyzed Sonogashira-type coupling reaction of arylboronic acids with terminal alkynes under air is described. The electron-deficient alkynes gave the desired cross-coupling products in good yields. Thus, it represents a simple and alternative method for the traditional Sonogashira reaction.
- Pan, Changduo,Luo, Fang,Wang, Wenhui,Ye, Zhishi,Cheng, Jiang
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supporting information; scheme or table
p. 5044 - 5046
(2009/12/05)
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- Preparation of α-bromoacrylates: One-pot procedure for the synthesis of conjugated acetylenic carboxylates from aldehydes with Ph3P/ Br3CCO2Et
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We have established the optimal conditions for the Wittig reaction for synthesizing α-bromoacrylates with a high selectivity, and developed a simple and efficient one-pot procedure for preparing various conjugated acetylenic carboxylates in moderate to high yields. Georg Thieme Verlag Stuttgart.
- Kim, Joong-Gon,Dong, Ho Kang,Doo, Ok Jang
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p. 443 - 447
(2008/04/01)
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- TACHYKININ RECEPTOR ANTAGONISTS
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The present invention relates to selective NK-1 receptor antagonists of Formula (I) or a pharmaceutically acceptable salt thereof, for the treatment of disorders associated with an excess of tachykinins.
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- Diaryl-enynes
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Provided, among other things, is a compound of Formula I: wherein: Ar1and Ar2are independently selected aryl groups, optionally substituted with up to five substituents independently selected from the group consisting of alkyl, alkox
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- Flash Vacuum Pyrolysis of Stabilised Phosphorus Ylides. Part 2. Two-step Conversion of Acid Chlorides into Acetylenic Esters and Terminal Alkynes
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The known thermal extrusion of Ph3PO from α-acyl-α-ethoxycarbonyl ylides 1 to give acetylenic esters 2 can be accomplished in excellent yield by using flash vacuum (FVP) at 500 deg C.Upon rasing the furnace temperature to 750 deg C, this reaction is accompanied by unexpected loss of the ethoxycarbonyl group to give the terminal alkynes 7 in moderate yield.A mechanism is proposed for this reaction based on isotopic labelling studies.Ten new examples of ylides 1 have been prepared for the first time.
- Aitken, R. Alan,Horsburg, Caroline E. R.,McCreadie, J. Graeme,Seth, Shirley
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p. 1727 - 1732
(2007/10/02)
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- Synthesis and Biological Evaluation of a Series of Substituted 4,5-Diphenylpyridine-2,6(1H,5H)-diones
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We report the synthesis of a series of disubstituted 4,5-diphenylpyridine-2,6(1H,5H)-diones (8), (10), (12)-(21), their characterization by 1H and 13 C n.m.r. spectroscopy and their receptor binding affinities for catecholamine and benzodiazepine receptors.
- Andrews, Peter R.,Brinkworth, Ross I.,Partridge, Ashton C.,Reiss, James A.
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p. 1717 - 1726
(2007/10/02)
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