- Visible Light-Driven Efficient Synthesis of Amides from Alcohols using Cu?N?TiO2 Heterogeneous Photocatalyst
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Amides were synthesized from alcohols and amines in high yields using an in situ generated active ester of N-hydroxyimide with our developed Cu?N?TiO2 catalyst at room temperature using oxygen as a sole oxidant under visible light. The catalyst can be easily prepared, robust, and recycled four times without a considerable change in catalytic activity. This developed protocol applies to a wide substrate scope and has good functional group tolerance. The application of this amidation reaction has been successfully demonstrated for the synthesis of moclobemide, an antidepressant drug, and an analog of the itopride drug on a gram scale.
- Singha, Krishnadipti,Ghosh, Subhash Chandra,Panda, Asit Baran
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supporting information
p. 657 - 662
(2021/02/02)
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- Cobalt-Catalyzed C(sp2)-H Carbonylation of Amino Acids Using Picolinamide as a Traceless Directing Group
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Herein we report an efficient protocol for the C(sp2)-H carbonylation of amino acid derivatives based on an inexpensive cobalt(II) salt catalyst. Carbonylation was accomplished using picolinamide as a traceless directing group, CO (1 atm) as the carbonyl
- Lukasevics, Lukass,Cizikovs, Aleksandrs,Grigorjeva, Liene
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supporting information
p. 2748 - 2753
(2021/04/12)
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- Rhodium-Catalyzed Copper-Assisted Intermolecular Domino C?H Annulation of 1,3-Diynes with Picolinamides: Access to Pentacyclic π-Extended Systems
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A new mode of reactivity of 1,3-diynes in rhodium-catalyzed oxidative annulation reactions has enabled the rapid assembly of extended π systems from readily available picolinamide derivatives. The process involves a double C?H bond activation and the iterative annulation of two 1,3-diyne units, with each alkyne moiety engaged in an orchestrated insertion sequence with high regiocontrol, leading to the formation of five new C?C bonds and the construction of four fused rings in a single operation. Either isoquinoline-1-carboxamides or fused polycyclic systems can be accessed by a switch in the regioselectivity of the second diyne insertion depending on the reaction conditions. DFT theoretical calculations have elucidated that the cooperative participation of both rhodium and copper in substrate activation, favored in the presence of excess of the copper(II) salt, is key to such a reversal of regioselectivity and subsequent multiple cyclization leading to fused polycyclic products. The role of copper was found to be essential in assisting both multiple insertion and rhodium-walking sequences, with the implication of intermediates with a Rh?Cu bond (2.60 ?).
- Martínez, ángel Manu,Alonso, Inés,Rodríguez, Nuria,Gómez Arrayás, Ramón,Carretero, Juan C.
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supporting information
p. 5733 - 5742
(2019/04/03)
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- [Cp*RhIII] in an Ionic Liquid as a Highly Efficient and Recyclable Catalytic Medium for Regio- and Diastereoselective Csp3–H Carbenoid Insertion
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Reported herein is a bidentate-assisted Csp3–H bond insertion using Cp*RhIII/IL as a highly efficient and recyclable catalytic medium, while showing good functional group tolerance. Notably, the application of ionic liquid not only lowered the temperature, but also enhanced the diastereoselectivity of this reaction. This work significantly expanded the scope of ionic liquids in Csp3–H functionalizations.
- Li, Jianglian,Zhou, Lin,Wang, Yaoling,Ma, Qiang,Lei, Yuan,Lai, Ruizhi,Luo, Yi,Hai, Li,Wu, Yong
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supporting information
p. 7448 - 7451
(2019/11/28)
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- Direct Amidation of Carboxylic Acids through an Active α-Acyl Enol Ester Intermediate
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The development of a highly efficient and simple protocol for the direct amidation of carboxylic acids is described employing ynoates as novel coupling reagents. The transformation proceeds in good to excellent yields via in situ α-acyl enol ester intermediates formation under mild reaction conditions. This useful method has been demonstrated for a range of substrates to provide a succinct access to structurally diverse amides, including key intermediates of glibenclamide, tiapride hydrochloride, and nateglinide, and can be conducted on a mole scale.
- Xu, Xianjun,Feng, Huangdi,Huang, Liliang,Liu, Xiaohui
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p. 7962 - 7969
(2018/06/18)
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- Chemoselective acylation of primary amines and amides with potassium acyltrifluoroborates under acidic conditions
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Current methods for constructing amide bonds join amines and carboxylic acids by dehydrative couplings-processes that usually require organic solvents, expensive and often dangerous coupling reagents, and masking other functional groups. Here we describe an amide formation using primary amines and potassium acyltrifluoroborates promoted by simple chlorinating agents that proceeds rapidly in water. The reaction is fast at acidic pH and tolerates alcohols, carboxylic acids, and even secondary amines in the substrates. It is applicable to the functionalization of primary amides, sulfonamides, and other N-functional groups that typically resist classical acylations and can be applied to late-stage functionalizations.
- Galvez, Alberto Osuna,Schaack, Cedric P.,Noda, Hidetoshi,Bode, Jeffrey W.
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supporting information
p. 1826 - 1829
(2017/02/15)
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- Lanthanum(III) triflate catalyzed direct amidation of esters
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Lanthanum trifluoromethanesulfonate is an effective single-component catalyst for synthesizing a variety of amides directly from esters and amines under mild conditions. Highly selective amidation of esters and amines, as well as catalyst-controlled amidation of esters, demonstrated the effectiveness of the catalyst system.
- Morimoto, Hiroyuki,Fujiwara, Risa,Shimizu, Yuhei,Morisaki, Kazuhiro,Ohshima, Takashi
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supporting information
p. 2018 - 2021
(2014/05/06)
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- Synthesis of alkylidene pyrrolo[3,4-b]pyridin-7-one derivatives via Rh III-catalyzed cascade oxidative alkenylation/annulation of picolinamides
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A practical RhIII-catalyzed cascade olefination/annulation of picolinamides leading to pyrrolo[3,4-b]pyridines has been developed. The reaction shows wide scope, complete regiocontrol and excellent stereoselectivity. This journal is the Partner Organisations 2014.
- Martínez, ángel Manu,Rodríguez, Nuria,Gómez Arrayás, Ramón,Carretero, Juan C.
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supporting information
p. 6105 - 6107
(2014/06/09)
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- Zinc(II)-catalyzed oxidative amidation of arylaldehydes with alkylamines under solvent-free conditions
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The first zinc-catalyzed oxidative amidation of arylaldehydes has been developed. Various amides were prepared in good yields under solvent-free and mild reaction conditions.
- Zhang, Min,Wu, Xiao-Feng
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supporting information
p. 1059 - 1062
(2013/04/10)
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- Synthesis of imides by palladium-catalyzed C-H functionalization of aldehydes with secondary amides
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An efficient palladium-catalyzed C-H functionalization of aldehydes with various N-substituted N-heteroarene-2-carboxamides has been developed for the synthesis of secondary imides. The reaction tolerates various functionalities, such as methoxy, fluoro, chloro, and bromo groups. A tentative radical mechanism for a PdII/PdIV catalytic cycle is proposed. Copyright
- Bian, Yong-Jun,Chen, Chao-Yue,Huang, Zhi-Zhen
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p. 1129 - 1133
(2013/02/23)
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- Iodination of remote ortho-C-H bonds of arenes via directed S EAr: A streamlined synthesis of tetrahydroquinolines
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A new strategy for the synthesis of tetrahydroquinolines (THQs) via the sequential functionalizations of remote C-H bonds is reported. This method uses a single picolinamide directing/protecting group to effect Pd-catalyzed γ-C(sp3)-H arylation, metal-free ε-C(sp2)-H iodination, and Cu-catalyzed intramolecular C-N cross-coupling. The overall sequence is efficient and versatile, and offers a streamlined synthesis of THQs with complex substitution patterns from readily available aryl iodide and aliphatic amine precursors.
- Nack, William A.,He, Gang,Zhang, Shu-Yu,Lu, Chengxi,Chen, Gong
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supporting information
p. 3440 - 3443
(2013/07/26)
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- Highly efficient syntheses of azetidines, pyrrolidines, and indolines via palladium catalyzed intramolecular amination of C(sp3)-H and C(sp2)-H bonds at γ and δ positions
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Efficient methods have been developed to synthesize azetidine, pyrrolidine, and indoline compounds via palladium-catalyzed intramolecular amination of C-H bonds at the γ and δ positions of picolinamide (PA) protected amine substrates. These methods feature relatively a low catalyst loading, use of inexpensive reagents, and convenient operating conditions. Their selectivities are predictable. These methods highlight the use of unactivated C-H bond, especially the C(sp3)-H bond of methyl groups, as functional groups in organic synthesis.
- He, Gang,Zhao, Yingsheng,Zhang, Shuyu,Lu, Chengxi,Chen, Gong
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supporting information; experimental part
p. 3 - 6
(2012/02/16)
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- Improved protocol for indoline synthesis via palladium-catalyzed intramolecular C(sp2)-H amination
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An efficient method has been developed for the synthesis of indoline compounds from picolinamide (PA)-protected β-arylethylamine substrates via palladium-catalyzed intramolecular amination of ortho-C(sp2)-H bonds. These reactions feature high efficiency, low catalyst loadings, mild operating conditions, and the use of inexpensive reagents.
- He, Gang,Lu, Chengxi,Zhao, Yingsheng,Nack, William A.,Chen, Gong
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supporting information; experimental part
p. 2944 - 2947
(2012/08/28)
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- Heterocycle synthesis via direct C-H/N-H coupling
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A method for five- and six-membered heterocycle formation by palladium-catalyzed C-H/N-H coupling is presented. The method employs a picolinamide directing group, PhI(OAc)2 oxidant, and toluene solvent at 80-120 °C. Cyclization is effective for sp2 as well as aliphatic and benzylic sp3 C-H bonds.
- Nadres, Enrico T.,Daugulis, Olafs
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supporting information; experimental part
p. 7 - 10
(2012/02/16)
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- Efficient alkyl ether synthesis via palladium-catalyzed, picolinamide-directed alkoxylation of unactivated C(sp3)-H and C(sp2)-H bonds at remote positions
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We report the efficient synthesis of alkyl ethers by the functionalization of unactivated sp3- and sp2-hybridized C-H bonds. In the Pd(OAc)2-catalyzed, PhI(OAc)2-mediated reaction system, picolinamide-protected amine substrates undergo facile alkoxylation at the γ or δ positions with a range of alcohols, including t-BuOH, to give alkoxylated products. This method features a relatively broad substrate scope for amines and alcohols, inexpensive reagents, and convenient operating conditions. This method highlights the emerging value of unactivated C-H bonds, particularly the C(sp3)-H bond of methyl groups, as functional groups in organic synthesis.
- Zhang, Shu-Yu,He, Gang,Zhao, Yingsheng,Wright, Kiwan,Nack, William A.,Chen, Gong
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supporting information; experimental part
p. 7313 - 7316
(2012/06/15)
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- New derivatives of benzylamide with anticonvulsant activity
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Previously obtained picolinic acid benzylamide is a potent anticonvulsant with low neurotoxicity. In search for new effective anticonvulsants twelve new benzylamides (1-12) were synthesized and preliminary evaluated in the Anticonvulsant Screening Program (ASP) of Antiepileptic Drug Development Program (ADDP) of NIH. Two of them appeared the most promising: 1- cyclopentenecarboxylic acid benzylamide (1- Cpc-BZA) (9) showed MES ED 50 = 85,36 mg/kg (PI = 2,49), scPTZ ED50 = 1,37 mg/kg (PI = 1,37), 6Hz-EST ED50 = 50,29 mg/kg and cyclopentanecarboxylic acid benzylamide (Cpc-BZA) (11) showed pilocarpine ED50 = 154.75 mg/kg and pilocarpine ED97 = 270.95 mg/kg.
- Strupinska, Marzanna,Rostafinska-Suchar, Grazyna,Stables, James. P.,Paruszewski, Ryszard
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experimental part
p. 155 - 159
(2009/06/18)
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- Direct ortho iodination of β- and γ-aryl alkylamine derivatives
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Two in one! A trifluoroacetamide protecting group not only masks an amine functionality, but also mimics peptidyl directing effects as a controlling unit in an efficient ortho iodination of a variety of biologically relevant small molecules (see example). (Chemical Equation Presented).
- Barluenga, Jose,Alvarez-Gutierrez, Julia M.,Ballesteros, Alfredo,Gonzalez, Jose M.
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p. 1281 - 1283
(2008/03/27)
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- Substituted 2,4-diaminopyrimidines
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Compounds of formula I STR1 wherein R1 is lower-alkoxy, R2 is bromine, lower-alkoxy or hydroxy, R3 is hydrogen, lower-alkyl, cycloalkyl, aryl, heterocyclyl, aralkyl, heterocyclyl-lower-alkyl or cyano, R4 and Rs
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- Synthesis, characterization and antitumor activity of novel gold (III) compounds with cisplatin-like structure
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Gold(III) centers are isoelectronic to Pt(II) compounds and adopt square-planar configurations similar to that of cisplatin, gold (III) compounds could display strong effects of tumor cell growth inhibition by a non-cisplatin-like mode of action. In our present work, we synthesized and characterized three gold(III) complexes which are coordinated by the N atom of amide group and investigated their in vitro anticancer activity, including their mechanism of action. In screening their in vitro activity, we found three gold complexes to exhibit selectivity of cytotoxicity, and complex 3 display better anticancer activity than another two gold(III) compounds and cisplatin. The three gold (III) complexes show preference to accumulation in mitochondria. The complex 3 could inhibit the growth of tumor cell by inducing the apoptosis mediated by ER-stress through loss of cellular homeostasis disrupts Ca2+ signaling. Based on our results, we believe complex 3 to be a promising anticancer agent or lead compound for further anticancer drug development.
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