- Silver-Catalyzed Acyl Nitrene Transfer Reactions Involving Dioxazolones: Direct Assembly of N-Acylureas
-
Dioxazolones and isocyanides are useful synthetic building blocks, and have attracted significant attention from researchers. However, the silver-catalyzed nitrene transfer reaction of dioxazolones has not been investigated to date. Herein, a silver-catalyzed acyl nitrene transfer reaction involving dioxazolones, isocyanides, and water was realized in the presence of Ag2O to afford a series of N-acylureas in moderate to good yields.
- Yang, Zheng-Lin,Xu, Xin-Liang,Chen, Xue-Rong,Mao, Zhi-Feng,Zhou, Yi-Feng
-
supporting information
p. 648 - 652
(2020/12/21)
-
- Synthesis of 3-nitroindoles by sequential paired electrolysis
-
3-Nitroindoles are synthetically versatile intermediates but current methods for the preparation hinder their widespread application. Herein, we report that nitroenamines undergo electrochemical cyclisation to 3-nitroindoles in the presence of potassium iodide. Detailed control experiments and cyclic voltammogram studies infer the reaction proceedsviaa sequential paired electrolysis process, beginning with anodic oxidation of iodide (I?) to the iodine radical (I˙), which facilitates cyclisation of the nitroenamine to give a 3-nitroindolinyl radical. Cathodic reduction and protonation generates a 3-nitroindoline that upon oxidation forms the 3-nitroindole.
- Kilmartin, Paul A.,Lindsay, Ashley C.,Sperry, Jonathan
-
supporting information
p. 7903 - 7913
(2021/09/28)
-
- Green Synthesis of Spiropyranone 3-Aryl-4-Methylcoumarin Derivatives using Carbonyldiimidazole
-
A series of spiropyranone 3-aryl-4-methylcoumarin derivatives have been synthesized from monospiro-2-hydroxy acetophenone in a novel and efficient green method using imidazolyl intermediates and inorganic base. Imidazolyl intermediates were in turn genera
- Ashok,Madhuri,Sarasija
-
p. 205 - 208
(2019/12/02)
-
- Microwave assisted synthesis of 4-methyl-3-arylpyrano[2,3-f]chromen-2(8H)-one derivatives, evaluation of antiproliferative, and antimicrobial activities
-
A series of new 4-methyl-3-arylpyrano[2,3-f]chromen-2(8H)-one derivatives were designed and synthesized through an efficient, an eco-friendly manner under microwave irradiation and conventional heating methods. Structures of final compounds established ba
- Dharavath, Ravinder,Sarasija, Madderla,Ram Reddy, Makthal,Nalaparaju, Nagaraju,Katta, Ramakrishna,Ashok, Dongamanti
-
p. 3943 - 3950
(2020/08/28)
-
- Ketoreductase catalyzed stereoselective bioreduction of α-nitro ketones
-
We report here the stereoselective bioreduction of α-nitro ketones catalyzed by ketoreductases (KREDs) with publicly known sequences. YGL039w and RasADH/SyADH were able to reduce 23 class I substrates (1-aryl-2-nitro-1-ethanone (1)) and ten class II substrates (1-aryloxy-3-nitro-2-propanone (4)) to furnish both enantiomers of the corresponding β-nitro alcohols, with good-to-excellent conversions (up to >99%) and enantioselectivities (up to >99% ee) being achieved in most cases. To the best of our knowledge, KRED-mediated reduction of class II α-nitro ketones (1-aryloxy-3-nitro-2-propanone (4)) is unprecedented. Select β-nitro alcohols, including the synthetic intermediates of bioactive molecules (R)-tembamide, (S)-tembamide, (S)-moprolol, (S)-toliprolol and (S)-propanolol, were stereoselectively synthesized in preparative scale with 42% to 90% isolated yields, showcasing the practical potential of our developed system in organic synthesis. Finally, the advantage of using KREDs with known sequence was demonstrated by whole-cell catalysis, in which β-nitro alcohol (R)-2k, the key synthetic intermediate of hypoglycemic natural product (R)-tembamide, was produced in a space-time yield of 178 g L?1 d?1 as well as 95% ee by employing the whole cells of a recombinant E. coli strain coexpressing RasADH and glucose dehydrogenase as the biocatalyst.
- Wang, Zexu,Wu, Xiaofan,Li, Zhining,Huang, Zedu,Chen, Fener
-
supporting information
p. 3575 - 3580
(2019/04/14)
-
- Efficient CDI/CH3SO3H-catalyzed, microwave-assisted synthesis of 2-substituted benzothiazoles
-
CDI combined with CH3SO3H was found to be highly effective for the cyclization of 2-aminothiophenol derivatives with carboxylic acids under MW condition. Fourteen benzothiazole derivatives were synthesized in good yield and their structures were characterized by1H-NMR,13C-NMR, IR and mass spectrometry. This simple, rapid synthetic method is believed to provide a useful process for the synthesis of 2-substituted benzothiazole compounds.
- Li, Yao-Wei,Zhang, Pei-Ming,Li, Rui,Bai, Yan,Yu, Yu,Gan, Zong-Jie
-
supporting information
p. 34 - 39
(2019/05/04)
-
- Efficient Copper-Catalyzed Multicomponent Synthesis of N-Acyl Amidines via Acyl Nitrenes
-
Direct synthetic routes to amidines are desired, as they are widely present in many biologically active compounds and organometallic complexes. N-Acyl amidines in particular can be used as a starting material for the synthesis of heterocycles and have several other applications. Here, we describe a fast and practical copper-catalyzed three-component reaction of aryl acetylenes, amines, and easily accessible 1,4,2-dioxazol-5-ones to N-acyl amidines, generating CO2 as the only byproduct. Transformation of the dioxazolones on the Cu catalyst generates acyl nitrenes that rapidly insert into the copper acetylide Cu-C bond rather than undergoing an undesired Curtius rearrangement. For nonaromatic dioxazolones, [Cu(OAc)(Xantphos)] is a superior catalyst for this transformation, leading to full substrate conversion within 10 min. For the direct synthesis of N-benzoyl amidine derivatives from aromatic dioxazolones, [Cu(OAc)(Xantphos)] proved to be inactive, but moderate to good yields were obtained when using simple copper(I) iodide (CuI) as the catalyst. Mechanistic studies revealed the aerobic instability of one of the intermediates at low catalyst loadings, but the reaction could still be performed in air for most substrates when using catalyst loadings of 5 mol %. The herein reported procedure not only provides a new, practical, and direct route to N-acyl amidines but also represents a new type of C-N bond formation.
- Van Vliet, Kaj M.,Polak, Lara H.,Siegler, Maxime A.,Van Der Vlugt, Jarl Ivar,Guerra, Célia Fonseca,De Bruin, Bas
-
supporting information
p. 15240 - 15249
(2019/10/19)
-
- Exploiting the Imidazolium Effect in Base-free Ammonium Enolate Generation: Synthetic and Mechanistic Studies
-
N-Acyl imidazoles and catalytic isothiourea hydrochloride salts function as ammonium enolate precursors in the absence of base. Enantioselective Michael addition–cyclization reactions using different α,β-unsaturated Michael acceptors have been performed to form dihydropyranones and dihydropyridinones with high stereoselectivity. Detailed mechanistic studies using RPKA have revealed the importance of the “imidazolium” effect in ammonium enolate formation and have highlighted key differences with traditional base-mediated processes.
- Young, Claire M.,Stark, Daniel G.,West, Thomas H.,Taylor, James E.,Smith, Andrew D.
-
p. 14394 - 14399
(2016/11/11)
-
- A practical synthesis of indoles via a Pd-catalyzed C-N ring formation
-
A method for the synthesis of N-functionalized C2-/C3-substituted indoles via Pd-catalyzed C-N bond coupling of halo-aryl enamines is described. The general strategy utilizes a variety of amines and β-keto esters which are elaborated into halo-aryl enamin
- Vaswani, Rishi G.,Albrecht, Brian K.,Audia, James E.,Cote, Alexandre,Dakin, Les A.,Duplessis, Martin,Gehling, Victor S.,Harmange, Jean-Christophe,Hewitt, Michael C.,Leblanc, Yves,Nasveschuk, Christopher G.,Taylor, Alexander M.
-
supporting information
p. 4114 - 4117
(2014/10/15)
-
- N-methylimidazole-catalyzed synthesis of carbamates from hydroxamic acids via the lossen rearrangement
-
An efficient, one-pot, N-methylimidazole (NMI) accelerated synthesis of aromatic and aliphatic carbamates via the Lossen rearrangement is reported. NMI is a catalyst for the conversion of isocyanate intermediates to the carbamates. Moreover, the utility of arylsulfonyl chloride in combination with NMI minimizes the formation of often-observed hydroxamate-isocyanate dimers during the sequence. Under the present conditions, lowering of temperatures is also possible, enabling a mild protocol.
- Yoganathan, Sabesan,Miller, Scott J.
-
supporting information
p. 602 - 605
(2013/04/11)
-
- Nucleophilic behaviour of DBU towards imidazolides: One-pot synthesis of ε-caprolactam derived carbamates and amides
-
Herein, we report the DBU ring opening reactions with imidazolide which can be a facile method to generate the library of ε-caprolactam derived carbamates and amides under one-pot condition.
- Nirmala, Rajagopalan,Ponpandian, Thanasekaran,Venkatraman,Rajagopal, Sridharan
-
p. 5181 - 5184
(2013/09/02)
-
- Efficient synthesis of substituted imidazo[4,5-b] pyridine
-
An efficient approach to the synthesis of 1-methylimidazo[4,5-b]pyridine derivatives 5-10 of biological interest has been developed. The key intermediate product 4 is obtained by cyclization of 2-amino-3-methylaminopyridine (3) with phenylacetic acid.
- Xing, Yuan-Yuan,Liu, Chuanxiang,Wu, Fanhong
-
p. 327 - 330
(2014/01/06)
-
- CDI-mediated monoacylation of symmetrical diamines and selective acylation of primary amines of unsymmetrical diamines
-
A highly efficient and green protocol for monoacylation of symmetrical diamines and chemoselective acylation of primary amines of unsymmetrical diamines has been developed.
- Verma, Sanjeev K.,Ghorpade, Ramarao,Pratap, Ajay,Kaushik
-
experimental part
p. 326 - 329
(2012/04/10)
-
- Solvent free, N,N'-carbonyldiimidazole (CDI) mediated amidation
-
The method involves CDI mediated amidation under solvent-free conditions. The protocol is green, simple, and scalable and has broad structural applicability. The protocol has also been used for BOC protection of amine. The protocol has reduced the time for CDI mediated amidation from 2-4 h to 5-10 min without the use of any dry organic solvent and nitrogen atmosphere.
- Verma, Sanjeev K.,Ghorpade, Ramarao,Pratap, Ajay,Kaushik
-
experimental part
p. 2373 - 2376
(2012/05/31)
-
- 7-Azabicyclo[2.2.1]heptane as a scaffold for the development of selective sigma-2 (σ2) receptor ligands
-
A series of N-substituted 7-azabicyclo[2.2.1]heptanes (12-17 and 22-25) and similarly substituted pyrrolidines (32-36 and 41-44) were synthesized as sterically-reduced, achiral analogs of adamantane- and trishomocubane-derived σ ligands. In vitro competition binding assays against σ receptors revealed that arylalkyl N-substituents conferred selectivity for the σ2 subtype, while alicyclic or polycarbocyclic substituents imparted high affinity for both subtypes. The σ2 binding and subtype selectivities of N-arylalkyl-7-azanorbornanes was generally greater than the analogously-substituted pyrrolidines, indicating that steric bulk and conformational restriction around the nitrogen atom are likely important for subtype discrimination.
- Banister, Samuel D.,Rendina, Louis M.,Kassiou, Michael
-
supporting information; experimental part
p. 4059 - 4063
(2012/07/03)
-
- Mild decarboxylative activation of malonic acid derivatives by 1,1′-carbonyldiimidazole
-
Chemical equations presented. Malonic acid derivatives undergo unusually mild decarboxylation when treated with N,N′-carbonyldiimidazole (CDI) at room temperature to generate the carbonyl imidazole moiety in high yield, which can be reacted further with a variety of nucleophiles in an efficient one-pot process.
- Lafrance, Danny,Bowles, Paul,Leeman, Kyle,Rafka, Robert
-
supporting information; experimental part
p. 2322 - 2325
(2011/06/26)
-
- Efficient synthesis of primary amides from carboxylic acids using n,n'-carbonyldiimidazole and ammonium acetate in ionic liquid
-
A novel and efficient method for the conversion of carboxylic acids to primary amides using N,N'-carbonyldiimidazole in combination with ammonium acetate/triethyl amine system in [BMIM]BF4 is developed.
- Lee, Kwan Soo,Kim, Kee D.
-
experimental part
p. 3497 - 3500
(2011/09/30)
-
- PYRIMIDINE INHIBITORS OF KINASE ACTIVITY
-
Described herein are compounds of formula (I) or pharmaceutical acceptable salts or solvates thereof, wherein G1, L1, R2, R3, n, p, Ar1, and Ar2 are defined in the description. Methods of making said compounds, and compositions comprising said compounds which are useful for inhibiting kinases such as IGF-IR are also disclosed.
- -
-
Page/Page column 59
(2010/12/26)
-
- Expedient synthesis of 3-hydroxyisoquinolines and 2-hydroxy-1,4- naphthoquinones via one-pot aryne acyl-alkylation/condensation
-
A convenient method is disclosed for the synthesis of both 3-hydroxyisoquinolines and 2-hydroxy-1,4-naphthoquinones from β-ketoesters using a one-pot aryne acyl-alkylation/condensation procedure. When performed in conjunction with a one-step method for the synthesis of the β-ketoester substrates, this method provides a new route to these polyaromatic structures in only two steps from commercially available carboxylic acid starting materials. The utility of this approach is demonstrated in the synthesis of the atropisomeric P,N-ligand, QUINAP. The Royal Society of Chemistry 2009.
- Allan, Kevin M.,Hong, Boram D.,Stoltz, Brian M.
-
supporting information; experimental part
p. 4960 - 4964
(2010/02/15)
-
- Acylguanidines as bioisosteres of guanidines: NG-acylated imidazolylpropylguanidines, a new class of histamine h2 receptor agonists
-
N1-Aryl(heteroaryl)alkyl-N2-[3-(1H-imidazol-4-yl) propyl]guanidines are potent histamine H2-receptor (H2R) agonists, but their applicability is compromised by the lack of oral bioavailability and CNS penetration. To improve pharmacokinetics, we introduced carbonyl instead of methylene adjacent to the guanidine moiety, decreasing the basicity of the novel H2R agonists by 4-5 orders of magnitude. Some acylguanidines with one phenyl ring were even more potent than their diaryl analogues. As demonstrated by HPLC-MS, the acylguanidines (bioisosteres of the alkylguanidines) were absorbed from the gut of mice and detected in brain. In GTPase assays using recombinant receptors, acylguanidines were more potent at the guinea pig than at the human H2R. At the hH1R and hH3R, the compounds were weak to moderate antagonists or partial agonists. Moreover, potent partial hH4R agonists were identified. Receptor subtype selectivity depends on the imidazolylpropylguanidine moiety (privileged structure), opening an avenue to distinct pharmacological tools including potent H4R agonists.
- Ghorai, Prasanta,Kraus, Anja,Keller, Max,G?tte, Carsten,Igel, Patrick,Schneider, Erich,Schnell, David,Bernhardt, Günther,Dove, Stefan,Zabel, Manfred,Elz, Sigurd,Seifert, Roland,Buschauer, Armin
-
supporting information; experimental part
p. 7193 - 7204
(2009/10/02)
-
- Multi-triggered self-immolative dendritic compounds
-
Novel self-immolative dendritic compounds which have a plurality of cleavable trigger units and hence can release a chemical moiety at their focal point upon a multi-triggering mechanism are disclosed. The novel self-immolative dendritic compounds are gated by a molecular logic gate, being either an AND or OR logic gate and hence can be beneficially used in a variety of biological, chemical and physical applications. Processes of preparing, compositions containing and methods utilizing the novel dendritic compounds are further disclosed.
- -
-
Page/Page column 22; sheet 2
(2010/11/24)
-
- Prodrug activation gated by a molecular "OR" logic trigger
-
(Chemical Equation Presented) Molecules that define logic: A molecular "OR" logic gate trigger has been demon-strated by masking a functional group in a doxorubicin prodrug with a linker that contains two cleavable substrates (input). The prodrug molecule was activated by two different enzymes to release the parent drug (see scheme; input red; output (drug) blue).
- Amir, Roey J.,Popkov, Mikhail,Lerner, Richard A.,Barbas III, Carlos F.,Shabat, Doron
-
p. 4378 - 4381
(2007/10/03)
-
- One-pot conversion of a representative series of carboxylic acids to the corresponding methyl ketones
-
The use of imidazolide activation method for direct acylation of Meldrum's acid with carboxylic acids, and the subsequent acidic hydrolysis of the acylated products to methyl ketones, provide a simple and efficient method for a one-pot conversion of carboxylic acids to the corresponding methyl ketones.
- Hamilakis, Stylianos,Tsolomitis, Athanase
-
p. 149 - 152
(2007/10/03)
-
- Self-immolative dendrimer biodegradability by multi-enzymatic triggering.
-
New self-immolative dendritic molecules have been designed and synthesized. The dendrons are built with a multi-enzymatic triggering mechanism, which initiates their biodegradation through a self-immolative chain fragmentation to release a reporter group
- Amir, Roey J,Shabat, Doron
-
p. 1614 - 1615
(2007/10/03)
-
- Kinetic and thermodynamic acidities of substituted 1-benzyl-1-methoxy-2-nitroethylenes. Strong reduction of the transition state imbalance compared to other nitroalkanes
-
Acidity constants of six substituted 1-benzyl-1-methoxy-2-nitroethylenes (2-Z with Z = m-NO2, m-CF3, m-Cl, H, p-Me, p-MeO) and their respective nitronic acids were determined in 50% DMSO-50% water (v/v) at 20 °C. Kinetic data were ob
- Bernasconi, Claude F.,Ali, Mahammad,Gunter, Janette C.
-
p. 151 - 157
(2007/10/03)
-
- The selective reaction of primary amines with carbonyl imidazole containing compounds: Selective amide and carbamate synthesis
-
matrix presented A new highly selective synthesis of amides and carbamates is described. In both cases the syntheses involve the formation of carbonyl imidazole intermediates which subsequently undergo previously unreported selective reactions with primary amines. Acid imidazolides with sufficient chain length will exclusively react with primary amines even in the presence of secondary and tertiary functionality. The imidazole carboxylic esters of secondary or tertiary alcohols also react selectively with primary amines, forming controlled carbamate structures.
- Rannard, Steve P.,Davis, Nicola J.
-
p. 2117 - 2120
(2007/10/03)
-
- Electroreductive synthesis of acylsilanes from acylimidazoles
-
Electroreduction of acylimidazoles in the presence of chlorotrimethylsilane gave the corresponding acylsilanes in satisfactory yields. Acylsilanes having a functional group such as an alkoxycarbonyl or chloro group also were synthesized effectively.
- Kise, Naoki,Kaneko, Hiroaki,Uemoto, Norihisa,Yoshida, Jun-Ichi
-
p. 8839 - 8842
(2007/10/02)
-
- A simple method for N-acylation of adenosine and cytidine nucleosides using carboxylic acids activated in-situ with carbonyldiimidazole
-
Carboxylic acids are activated with 1,1'-carbonyldiimidazole in acetonitrile to form N-acylimidazoles which are then treated with per-trimethylsilyl ethers of nucleosides adenosine or cytidine at ambient temperature to generate exclusively N-acylated-Aden
- Sinha,Sinha, Nanda D.,Davis,Davis, Peter,Schultze,Schultze, Lisa M.,Upadhya,Upadhya, Krishna
-
p. 9277 - 9280
(2007/10/02)
-
- New Tetracyclic Derivatives of Imidazobenzodiazepines and of Imidazothienodiazepines
-
The synthesis of new tetracyclic 1,4-diazepine derivatives is described.In these compounds, an additional five-membered heterocycle is fused on the known tricyclic ring systems imidazobenzodiazepine and imidazothienodiazepine.Many of these new compounds display a very high affinity to the benzodiazepine receptor in mammals.
- Gerecke, Max,Kyburz, Emilio,Borer, Rene,Gassner, Walter
-
p. 693 - 722
(2007/10/02)
-
- Regiospecific Synthesis, Structure, and Fluorescence Properties of Highly Substituted Imidazopyridines and Pyridobenzimidazoles
-
1-(Arylacetyl)imidazoles 1 react with acetylenedicarboxylic esters to provide highly functionalized imidazopyridines 2 in up to 89percent yield.The scope and limitations of this novel condensation reaction have been investigated, and a mechanistic interpretation is presented.A strong effect on the yield of this reaction is observed for electron-donating and electron-withdrawing substituents in the para position of the aryl ring.Moreover, the transformation is shown to proceed in a regiospecific manner starting with 4,5-unsymmetrically substituted 1-(arylacetyl)imidazoles (1d-g) and is extended to the synthesis of the corresponding pyridobenzimazoles 12.The crystal structure of derivative 2a has been determined by X-ray analysis.Imidazopyridines 2 and pyridobenzimidazoles 12, obtained by this procedure, are highly fluorescent in the visible region with characteristically large Stokes shifts.
- Knoelker, Hans-Joachim,Boese, Roland,Hitzemann, Rainer
-
p. 327 - 339
(2007/10/02)
-
- A SIMPLE METHOD FOR THE DIRECT BIS-ACYLATION THE PRIMARY AMINO GROUPS IN SPERMIDINE AND OTHER LINEAR TRIAMINES
-
A simple and efficient method for the direct symmetrical bis-acylation of spermidine and other linear triamines using acylimidazoles is described.By this procedure, the siderophore natural product N1,N8-bis(2,3-dihydroxybenzoyl) spermidine was synthesized in an overall yield of 70percent in two steps.
- Joshua, Alummoottil V.,Scott, John R.
-
p. 5725 - 5728
(2007/10/02)
-
- PREPARATION OF ALLYL 2,3,4-TRI-O-ALLYL-D-GLUCOPYRANURONATE AND OF 1-O-ACYL-D-GLUCOPYRANURONIC ACIDS: ATTEMPTED SYNTHESIS OF 1-O-BILIRUBIN-D-GLUCURONIC ACIDS
-
Allyl 2,3,4-tri-O-allyl-D-glucopyranuronate (7) has been prepared (overall yield, 37percent) from methyl 1,2,3,4-tetra-O-acetyl-α- or -β-D-glucopyranuronate via a six-step reaction procedure. 1-O-Acetyl-, 1-O-methacroyl-, and 1-O-phenylacetyl-αβ-D-glucopy
- Compernolle, Frans
-
p. 177 - 184
(2007/10/02)
-