Copper-catalyzed CuAAC/intramolecular C–H arylation sequence: Synthesis of annulated 1,2,3-triazoles

• Rajkumar Jeyachandran,
• Harish Kumar Potukuchi and
• Lutz Ackermann

Beilstein J. Org. Chem. 2012, 8, 1771–1777, doi:10.3762/bjoc.8.202

• Rutjes [68] as well as Sharpless [69] elegantly devised alternative approaches exploiting 1-haloalkynes [70], we became interested in exploring a single [71][72][73] inexpensive copper catalyst for one-pot reaction sequences comprising a 1,3-dipolar cycloaddition along with an intramolecular C–H bond

• catalytic efficacy. Subsequently, we explored the extension of this approach to the development of a chemoselective three-component one-pot reaction. Thus, we found that alkyl bromides 2 could be directly employed as user-friendly substrates for the in situ formation of the corresponding organic azides

• (Scheme 3). Notably, the catalytic system proved broadly applicable, and a variety of organic electrophiles 2, thereby, delivered differently decorated N-substituted 1,4-dihydrochromeno[3,4-d][1,2,3]triazoles 4. Importantly, performing the one-pot reaction in a sequential fashion was not found to be

Enantioselective total synthesis of (R)-(−)-complanine

• Krystal A. D. Kamanos and
• Jonathan M. Withey

Beilstein J. Org. Chem. 2012, 8, 1695–1699, doi:10.3762/bjoc.8.192

• turned to its conversion to amino alcohol 4. It was envisioned that such conversion could be effected in a one-pot reaction by employing lithium aluminium hydride reduction of an aldoximine [5], formed in situ by condensation of a suitably oxygenated aldehyde 5 with hydroxylamine hydrochloride (Scheme 3

Asymmetric one-pot sequential Friedel–Crafts-type alkylation and α-oxyamination catalyzed by a peptide and an enzyme

• Kengo Akagawa,
• Ryota Umezawa and
• Kazuaki Kudo

Beilstein J. Org. Chem. 2012, 8, 1333–1337, doi:10.3762/bjoc.8.152

• -functionalized indole or pyrrole derivatives in a highly enantioselective manner. Keywords: Friedel–Crafts-type alkylation; laccase; one-pot reaction; organocatalysis; α-oxyamination; resin-supported peptide catalyst; Findings Indole derivatives represent a class of biologically active compounds [1][2][3], and

• followed by oxygenation at the α-position of the carbonyl group. If such a sequence can be realized in a one-pot reaction, it would be a powerful method for the synthesis of oxy-functionalized indole derivatives with operational simplicity. To date, there has been no report on the FCAA reaction combined

• oxyamination, even though indoles are generally prone to be oxidized [39][40]. By considering that enzymes promote reactions efficiently under aqueous conditions, we thought it necessary to conduct the one-pot reaction in aqueous media. Therefore, the reaction sequence shown in Table 1 was first examined in

Facile isomerization of silyl enol ethers catalyzed by triflic imide and its application to one-pot isomerization–(2 + 2) cycloaddition

• Kazato Inanaga,
• Yu Ogawa,
• Yuuki Nagamoto,
• Akihiro Daigaku,
• Hidetoshi Tokuyama,
• Yoshiji Takemoto and
• Kiyosei Takasu

Beilstein J. Org. Chem. 2012, 8, 658–661, doi:10.3762/bjoc.8.73

• sequence, Tf2NH catalyzes both of the reactions. Keywords: isomerization; one-pot reaction; organocatalysis; silyl enol ethers; triflic imide; Introduction Silyl enol ethers, which are isolable equivalents of metal enolates, are useful and important intermediates in synthetic chemistry [1][2][3]. They

• ) cycloaddition of silyl enol ethers with acrylates generating substituted cyclobutanes [10]. We are intrigued that the isomerization of silyl enol ethers and successive (2 + 2) cycloaddition could be promoted by Tf2NH in a one-pot reaction. When 1a was treated with Tf2NH (1 mol %) under the isomerization

• silyl enol ethers. Kinetically favourable silyl enol ethers were smoothly converted into thermodynamically stable ones by treatment with a catalytic amount of Tf2NH under mild conditions. Moreover, we demonstrated that the one-pot reaction involves two different catalytic reactions, an isomerization and

Stereoselective, nitro-Mannich/lactamisation cascades for the direct synthesis of heavily decorated 5-nitropiperidin-2-ones and related heterocycles

• Pavol Jakubec,
• Dane M. Cockfield,
• Madeleine Helliwell,
• James Raftery and
• Darren J. Dixon

Beilstein J. Org. Chem. 2012, 8, 567–578, doi:10.3762/bjoc.8.64

• /bjoc.8.64 Abstract A versatile nitro-Mannich/lactamisation cascade for the direct stereoselective synthesis of heavily decorated 5-nitropiperidin-2-ones and related heterocycles has been developed. A highly enantioenriched substituted 5-nitropiperidin-2-one was synthesised in a four component one-pot

• reaction combining an enantioselective organocatalytic Michael addition with the diastereoselective nitro-Mannich/lactamisation cascade. Protodenitration and chemoselective reductive manipulation of the heterocycles was used to install contiguous and fully substituted stereocentres in the synthesis of

Enaminones in a multicomponent synthesis of 4-aryldihydropyridines for potential applications in photoinduced intramolecular electron-transfer systems

• Nouria A. Al-Awadi,
• Maher R. Ibrahim,
• Mohamed H. Elnagdi,
• Elizabeth John and
• Yehia A. Ibrahim

Beilstein J. Org. Chem. 2012, 8, 441–447, doi:10.3762/bjoc.8.50

• -transfer system. Results and Discussion In the present work we have investigated the synthesis of DHPs 2 from 1, aromatic aldehydes, and ammonia or primary amines, in a three-component one-pot reaction. First, we investigated different conditions to achieve this goal (Scheme 2, Table 1). Thus, the reaction

Synthesis, solid-state fluorescence properties, and computational analysis of novel 2-aminobenzo[4,5]thieno[3,2-d]pyrimidine 5,5-dioxides

• Kenichirou Yokota,
• Masayori Hagimori,
• Naoko Mizuyama,
• Yasuhisa Nishimura,
• Hiroshi Fujito,
• Yasuhiro Shigemitsu and
• Yoshinori Tominaga

Beilstein J. Org. Chem. 2012, 8, 266–274, doi:10.3762/bjoc.8.28

• ]pyrimidine 5,5-dioxides (3a–g), were synthesized in good yields by a convenient one-pot reaction of 2-[bis(methylsulfanyl)methylene]benzo[b]thiophene-3(2H)-one 1,1-dioxide (1a) with guanidine carbonate (2a) or (S)-methylisothiourea sulfate (2b) under reflux in pyridine. Benzo[4,5]thieno[3,2-d]pyrimidine

Pseudo five-component synthesis of 2,5-di(hetero)arylthiophenes via a one-pot Sonogashira–Glaser cyclization sequence

• Dominik Urselmann,
• Dragutin Antovic and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 1499–1503, doi:10.3762/bjoc.7.174

• [3], were easily accessed in a one-pot procedure. Starting from the stable and readily available aryliodides 1n and 1o, the presented new methodology allowed the synthesis of both molecules in a quick, simple and economic one-pot reaction. Moreover, the usual preparation and isolation of boronic

Amines as key building blocks in Pd-assisted multicomponent processes

• Didier Bouyssi,
• Nuno Monteiro and
• Geneviève Balme

Beilstein J. Org. Chem. 2011, 7, 1387–1406, doi:10.3762/bjoc.7.163

• was developed by Lu and co-workers [33]. This one-pot reaction is based on a stepwise synthesis of indole derivatives reported by Cachi’s group, and involves, in the last step, a palladium-mediated cyclization of o-alkynylaniline derivatives in the presence of aryl halides [34]. In this process

• order to suppress the concurrent formation of 2-substituted indoles 60 by direct cyclization of o-alkynylaniline intermediates under the classical Sonogashira reaction conditions. Interestingly, aryl bromides were used as a third partner and may be added at the beginning of this one-pot reaction since

PEG-embedded KBr₃: A recyclable catalyst for multicomponent coupling reaction for the efficient synthesis of functionalized piperidines

• Sanny Verma,
• Suman L. Jain and
• Bir Sain

Beilstein J. Org. Chem. 2011, 7, 1334–1341, doi:10.3762/bjoc.7.157

• . Keywords: heterocycles; metal free synthesis; multicomponent coupling; piperidine; recyclable catalyst; Introduction Multicomponent reactions [1][2][3][4][5], involving the one-pot reaction of three or more components to produce valuable compounds, have been recognized as one of the important tools to

Directed ortho,ortho'-dimetalation of hydrobenzoin: Rapid access to hydrobenzoin derivatives useful for asymmetric synthesis

• Inhee Cho,
• Labros Meimetis,
• Lee Belding,
• Michael J. Katz,
• Travis Dudding and
• Robert Britton

Beilstein J. Org. Chem. 2011, 7, 1315–1322, doi:10.3762/bjoc.7.154

• . Importantly, a wide variety of chiral diols (e.g., Vivol (4)) are now readily accessible in optically pure form following this one-pot reaction. Although the range of electrophiles that engage in synthetically useful reactions with the tetralithio intermediate 8 is limited, the diiodohydrobenzoin 12 and bis

Recent advances in the gold-catalyzed additions to C–C multiple bonds

• He Huang,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103

• -catalyzed cascade transformation sequence (Scheme 56). The strategy affords a straightforward and efficient construction of tricyclic lactam molecular architectures in which several carbon–carbon and carbon–nitrogen bonds are formed in a one-pot reaction from simple starting materials [166]. The catalytic

Gold-catalyzed propargylic substitutions: Scope and synthetic developments

• Olivier Debleds,
• Eric Gayon,
• Emmanuel Vrancken and
• Jean-Marc Campagne

Beilstein J. Org. Chem. 2011, 7, 866–877, doi:10.3762/bjoc.7.99

• an one-pot, sequential, reaction with first a gold(III)-catalyzed propargylic substitution followed by a gold(I)-catalyzed cycloisomerization, the bicyclic compound 37 was obtained in 71% yield [24][80][81][82]. Very recently, a remarkable one-pot reaction using an original gold(III) catalyst has

Metathesis access to monocyclic iminocyclitol-based therapeutic agents

• Ileana Dragutan,
• Valerian Dragutan,
• Carmen Mitan,
• Hermanus C.M. Vosloo,
• Lionel Delaude and
• Albert Demonceau

Beilstein J. Org. Chem. 2011, 7, 699–716, doi:10.3762/bjoc.7.81

• synthesis of (2S,3R,4S)-3,4-dihydroxyproline (30) (Scheme 5). According to their methodology, (R)-2,3-O-isopropylidene-D-glyceraldehyde (24) was treated in a one-pot reaction with benzylamine and then subjected to Grignard addition with vinylmagnesium bromide to provide the alkene 25 as a single

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

• Marcus Baumann,
• Ian R. Baxendale,
• Steven V. Ley and
• Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

• . Alternatively, in order to circumvent the regioselectivity issue, other pyrazole syntheses have been used. For example, the substituted aryl hydrazine 237 can be reacted with trifluoromethyl butynone in a one pot reaction. A Michael addition/cyclisation sequence renders only the desired regioisomer of the

Synthesis and self-assembly of 1-deoxyglucose derivatives as low molecular weight organogelators

• Guijun Wang,
• Hao Yang,
• Sherwin Cheuk and
• Sherman Coleman

Beilstein J. Org. Chem. 2011, 7, 234–242, doi:10.3762/bjoc.7.31

• one pot reaction of the acid chloride with the headgroup (Scheme 1). In general, three products were obtained, which could be separated by flash chromatography. Our previous results had shown that esterification of headgroup 1 typically gave the 2-monoester as the major product, but when the headgroup

• (temperature range 25–50 °C) and Max 4000 incubator (temperature range 25–60 °C) from Barnstead. General procedure for the synthesis of ester derivatives of compound 8 The three ester derivatives A, B, and C were synthesized in a one pot reaction by reacting the corresponding acid chloride (1.2 equiv) with

First synthesis of 2-(benzofuran-2-yl)-6,7-methylene dioxyquinoline-3-carboxylic acid derivatives

• Wentao Gao,
• Jia Liu,
• Yun Jiang and
• Yang Li

Beilstein J. Org. Chem. 2011, 7, 210–217, doi:10.3762/bjoc.7.28

• yield (69%). The yields and melting points of all the synthesized products 3a–h are listed in Table 1. It is noteworthy that in the one-pot reaction the use of 30% ethanolic potassium hydroxide solution is sufficient to promote the reaction and there were no improvement in the reaction rates and yields

• good to high yield from the one-pot reaction of 2-chloromethylquinoline 5 with a variety of salicylaldehydes. In the case of entry 7, the reaction of 3,5-di-tert-butylsalicylaldedyde (6g) with 5 gave the corresponding product 3g in a moderate yield of 52%, which might be attributed to the sterically

• Wentao Gao Jia Liu Yun Jiang Yang Li Institute of Superfine Chemicals, Bohai University, Jinzhou 121000, China 10.3762/bjoc.7.28 Abstract A facile and inexpensive synthesis of a series of novel methylenedioxy-bearing 2-(benzofuran-2-yl)-quinoline-3-carboxylic acid derivatives 3a–h via the one-pot

Approaches towards the synthesis of 5-aminopyrazoles

• Ranjana Aggarwal,
• Vinod Kumar,
• Rajiv Kumar and
• Shiv P. Singh

Beilstein J. Org. Chem. 2011, 7, 179–197, doi:10.3762/bjoc.7.25

• and sodium nitrite in water at 0–5 °C to provide an intermediate diazonium salt. The latter underwent cycloaddition with an isocyanate in a one-pot reaction to give compound 43 (Scheme 10) [41]. 5-Aminopyrazoles 45 have recently been prepared by Boc deprotection of the α-hydrazino acids 44 with TFA in

SbCl₃-catalyzed one-pot synthesis of 4,4′-diaminotriarylmethanes under solvent-free conditions: Synthesis, characterization, and DFT studies

• Ghasem Rezanejade Bardajee

Beilstein J. Org. Chem. 2011, 7, 135–144, doi:10.3762/bjoc.7.19

• 2971, 3039 cm−1 (for C–H of OCH3), 3130 and 3134 cm−1 (C–H symmetric stretching vibrations) are also not discernable in the experimental IR spectrum. Conclusion In summary, it has been demonstrated that SbCl3 is a mild and efficient catalyst for the one-pot reaction of N,N-dimethylaniline with a

A new and facile synthetic approach to substituted 2-thioxoquinazolin-4-ones by the annulation of a pyrimidine derivative

• Nimalini D. Moirangthem and
• Warjeet S. Laitonjam

Beilstein J. Org. Chem. 2010, 6, 1056–1060, doi:10.3762/bjoc.6.120

• active methylene compounds, such as, malononitrile and ethylcyanoacetate. Results and Discussion DTBA are among the simplest synthetic intermediates and can be easily prepared in a one-pot reaction by treating 1,3-diaryl thioureas with malonic acid in the presence of acetyl chloride. DTBA undergoes

Formation of epoxide-amine oligo-adducts as OH-functionalized initiators for the ring-opening polymerization of ε-caprolactone

• Julia Theis and
• Helmut Ritter

Beilstein J. Org. Chem. 2010, 6, 938–944, doi:10.3762/bjoc.6.105

• polymerization (ROP) of ε-caprolactone to construct a new class of graft copolymers. Results and Discussion Formation of epoxide-amine adducts Epoxide-amine adducts based on diglycidyl ether of bisphenol A (1) and 4-aminoanisole (3) were synthesized in a MW-assisted one-pot reaction. Thus, 4-nitroanisole (2) was

• calorimetry (DSC) curve of compound 4 shows a glass transition temperature (Tg) at 63 °C. The low molecular weight epoxide-amine adduct 4 is soluble, e.g., in tetrahydrofuran (THF), methanol, chloroform but insoluble in n-hexane and water. We also carried out the above described one-pot reaction in THF as

Novel loop-like aromatic compounds: a further step on the road to nanobelts and nanotubes

• Venkataramana Rajuri,
• Dariush Ajami,
• Gaston R. Schaller,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2010, 6, No. 30, doi:10.3762/bjoc.6.30

• analysis. The pure hydrocarbons 2 and 3 were prepared by Diels–Alder reaction of either 7 or 1 [20] with 1,2-bis(dibromomethyl)benzene (8) and sodium iodide to furnish the desired compounds, 2 and 3, in 60 and 40% yield, respectively (Scheme 1 and Scheme 2). During this simple one pot reaction, the sodium

Concise methods for the synthesis of chiral polyoxazolines and their application in asymmetric hydrosilylation

• Wei Jie Li,
• Zun Le Xu and
• Sheng Xiang Qiu

Beilstein J. Org. Chem. 2010, 6, No. 29, doi:10.3762/bjoc.6.29

• , Sun Yat-Sen University, 135 Xingang West Road, Haizhou District, Guangzhou 510275, China 10.3762/bjoc.6.29 Abstract Seven polyoxazoline ligands were synthesized in high yield in a one-pot reaction by heating polycarboxylic acids or their esters and chiral β-amino alcohols under reflux with

• water or methanol in a one-pot reaction, to give the bisoxazolines 1–3 in good yields (entries 1–6). However, when triglycine or its triethyl ester, BTA or TBTA, was heated with (R)-2-amino-1-butanol in toluene, good yields of the desired products were not obtained, even after 24 h. To resolve this

Synthesis of bis(3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoyl)(phenyl)phosphine oxide – a tailor-made photoinitiator for dental adhesives

• Norbert Moszner,
• Iris Lamparth,
• Jörg Angermann,
• Urs Karl Fischer,
• Frank Zeuner,
• Thorsten Bock,
• Robert Liska and
• Volker Rheinberger

Beilstein J. Org. Chem. 2010, 6, No. 26, doi:10.3762/bjoc.6.26

• the formed hydroxymethyl compound with concentrated hydrochloric acid in a one-pot reaction [15]. In the first step of the WBAPO synthesis (Scheme 2), 3-(chloromethyl)-2,4,6-trimethylbenzoic acid was coupled with 2-(allyloxy)ethanol using potassium hydroxide in excess of 2-(allyloxy)ethanol as solvent

Bis(oxazolines) based on glycopyranosides – steric, configurational and conformational influences on stereoselectivity

• Tobias Minuth and
• Mike M. K. Boysen

Beilstein J. Org. Chem. 2010, 6, No. 23, doi:10.3762/bjoc.6.23

• conformative effect is also in operation for allo-configured bis(oxazolines), we prepared ligand Ac alloBox 16 with acyclic 4,6-O-protection by the removal of the benzylidene groups from 12 under acidic conditions and per-O-acetylation in a one-pot reaction followed by NIS-mediated cyclisation of resulting bis