Multicomponent reactions (MCRs): a useful access to the synthesis of benzo-fused γ-lactams

• Edorta Martínez de Marigorta,
• Jesús M. de Los Santos,
• Ana M. Ochoa de Retana,
• Javier Vicario and
• Francisco Palacios

Beilstein J. Org. Chem. 2019, 15, 1065–1085, doi:10.3762/bjoc.15.104

• one (path A), decarboxylative coupling to form intermediates 14 and 15, followed by a cyclization take place, while in the second path (B), the first step seems to be the formation of amide 16. Indeed, another multicomponent approach to isoindolinones uses iodobenzamides 17 as starting materials

• = OH, conditions B, Scheme 9) instead of diketones and a quaternary ammonium salt as catalyst in water. In this multicomponent decarboxylative alkylation/cyclization process, they prepared several lactam derivatives 36 with good yields. While the first research group suggests that the reaction would

New α- and β-cyclodextrin derivatives with cinchona alkaloids used in asymmetric organocatalytic reactions

• Iveta Chena Tichá,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2019, 15, 830–839, doi:10.3762/bjoc.15.80

• –Hillman and aldol-type reactions, we focused on their application in the decarboxylative asymmetric allylic amination (AAA) [38] of MBH carbamate 12 affording the product 13 with enantiomeric excesses of up to 75% (Scheme 4). However, compared with the published procedure [38] (up to 97% ee, aromatic

• the decarboxylative asymmetric allylic amination of a Morita–Baylis–Hillman carbamate (10 mol % of catalyst, up to 75% ee, up to 76% isolated yield). We believe that these new CD derivatives comprising cinchona alkaloids will be suitable catalysts of other asymmetric reactions using them under green

Targeting the Pseudomonas quinolone signal quorum sensing system for the discovery of novel anti-infective pathoblockers

• Christian Schütz and
• Martin Empting

Beilstein J. Org. Chem. 2018, 14, 2627–2645, doi:10.3762/bjoc.14.241

• formed by action of the heterodimeric complex PqsBC. This time, CoA-activated octanoic acid is used to preload an active-site cysteine of PqsC with the fatty acid via a thioester linkage [30][31]. The previously produced 2-ABA is then consumed to from HHQ under decarboxylative condensation [30]. Finally

Investigations of alkynylbenziodoxole derivatives for radical alkynylations in photoredox catalysis

• Yue Pan,
• Kunfang Jia,
• Yali Chen and
• Yiyun Chen

Beilstein J. Org. Chem. 2018, 14, 1215–1221, doi:10.3762/bjoc.14.103

• group first used alkynylbenziodoxoles for decarboxylative radical alkynylation under silver salt and persulfate conditions [19]. In 2014, the Chen group discovered that alkynylbenziodoxoles (BI-alkyne) readily participated in photoredox catalysis as the radical alkynylation reagent [20], after which

• 8 as the acyl radical precursor, the decarboxylative alkynylation with BI-alkyne derivatives afforded ynone 9 under the photoredox conditions [21]. Both the unsubstituted and 3,4-dimethoxy substituted BI’-alkynes 3c and 3f gave ynone 9 in similar 77–79% yields, while the 3,4-difluoro substituted BI

One hundred years of benzotropone chemistry

• Arif Dastan,
• Haydar Kilic and
• Nurullah Saracoglu

Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98

Hypervalent iodine(III)-mediated decarboxylative acetoxylation at tertiary and benzylic carbon centers

• Kensuke Kiyokawa,
• Daichi Okumatsu and
• Satoshi Minakata

Beilstein J. Org. Chem. 2018, 14, 1046–1050, doi:10.3762/bjoc.14.92

• Kensuke Kiyokawa Daichi Okumatsu Satoshi Minakata Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan 10.3762/bjoc.14.92 Abstract The decarboxylative acetoxylation of carboxylic acids using a combination of PhI(OAc)2 and

• . Keywords: acetoxylation; carboxylic acids; decarboxylation; hypervalent iodine; iodine; Introduction The decarboxylative functionalization of carboxylic acids and the derivatives thereof is an important transformation in organic synthesis. In recent years, increasing efforts have been devoted to the

• development of decarboxylative transformations [1][2][3][4][5][6][7][8][9][10][11][12][13], especially through radical decarboxylation processes, allowing an easy access to valuable compounds from readily available carboxylic acids. However, despite these advances, the oxidative decarboxylation coupled with C

High-yielding continuous-flow synthesis of antimalarial drug hydroxychloroquine

• Eric Yu,
• Hari P. R. Mangunuru,
• Nakul S. Telang,
• Caleb J. Kong,
• Jenson Verghese,
• Stanley E. Gilliland III,
• Saeed Ahmad,
• Raymond N. Dominey and
• B. Frank Gupton

Beilstein J. Org. Chem. 2018, 14, 583–592, doi:10.3762/bjoc.14.45

• ]. With these issues in mind, we carried out a retrosynthetic analysis (Scheme 2) in which 10, an iodo analogue to the starting material 3, could be generated in a single step via a decarboxylative ring-opening of α-acetyl butyrolactone 8. The iodo analogue 10 could then be used without isolation to

Progress in copper-catalyzed trifluoromethylation

• Guan-bao Li,
• Chao Zhang,
• Chun Song and
• Yu-dao Ma

Beilstein J. Org. Chem. 2018, 14, 155–181, doi:10.3762/bjoc.14.11

• was paid on trifluoroacetates. Trifluoroacetate is readily available and one of the cheapest and most convenient sources of the trifluoromethylation for both industrial and medicinal purposes. In 2011, a practical and ligand-free Cu-catalyzed decarboxylative trifluoromethylation of aryl iodides was

• economic decarboxylative trifluoromethylation reagent [Cu(phen)O2CCF3], which was prepared from readily available and inexpensive starting materials (Scheme 8). Treatment of copper tert-butoxide with phen, followed by addition of trifluoroacetic acid afforded the air-stable [Cu(phen)O2CCF3] complex, which

From dipivaloylketene to tetraoxaadamantanes

• Gert Kollenz and
• Curt Wentrup

Beilstein J. Org. Chem. 2018, 14, 1–10, doi:10.3762/bjoc.14.1

• hydrolysis of the bisdioxines proceeds through the addition of water to a C=C double bond and results in a second transannular oxa-Michael-type reaction and generation of tetraoxaadamantanes 5. This reaction is decarboxylative when free carboxylic acid functions are present in the bisdioxines, thus forming

• reaction (Scheme 7), and not in the final products, which are not prone to decarboxylation: the stable bis-carboxylic acid 24 can be obtained by hydrogenolysis of the dibenzyl ester 23 (Scheme 6) [30]. The reaction may be seen as a decarboxylative [31][32] oxa-Michael addition (Scheme 7) and may be related

• ) derived from dipivaloylketene (2). Mechanisms of formation of bisdioxine acid derivatives from dimer 3. Recently reported synthesis of chromenobisdioxines. Formation of tetraoxaadamantanes. Decarboxylative hydrolysis and oxa-Michael-type ring closure. Oxime and hydrazine derivatives of bisdioxines and

Quinone-catalyzed oxidative deformylation: synthesis of imines from amino alcohols

• Xinyun Liu,
• Johnny H. Phan,
• Benjamin J. Haugeberg,
• Shrikant S. Londhe and
• Michael D. Clift

Beilstein J. Org. Chem. 2017, 13, 2895–2901, doi:10.3762/bjoc.13.282

• decarboxylative homologation of α-amino acids [32], which demonstrated for the first time that quinone organocatalysts can be utilized to enable oxidative C–C bond cleavage to provide versatile imine intermediates. To further exploit the utility of this chemistry, we sought to develop a new method for the

• iminoquinone intermediate is likely required for productive reactivity. To demonstrate the synthetic utility of this methodology, we performed a sequential oxidative deformylation/Mukaiyama−Mannich addition under our previously reported conditions for decarboxylative amino acid homologation (Scheme 4) [32]. In

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

• decarboxylative trifluoromethylation of α,β-unsaturated carboxylic acids in the presence of CF3SO2Na and TBHP [82]. Various (hetero)arenes were compatible with these reaction conditions

A Brønsted base-promoted diastereoselective dimerization of azlactones

• Danielle L. J. Pinheiro,
• Gabriel M. F. Batista,
• Pedro P. de Castro,
• Leonã S. Flores,
• Gustavo F. S. Andrade and
• Giovanni W. Amarante

Beilstein J. Org. Chem. 2017, 13, 2663–2670, doi:10.3762/bjoc.13.264

• strongly dependent on the base, as well as the substituent at the C2 position [24]. Once again, no comments concerning the stereochemistry were addressed. Thus, we started this study envisioning the trichloromethylation of azlactones through the decarboxylative potassium trichloroacetate (KTCA) in DMSO

Regioselective decarboxylative addition of malonic acid and its mono(thio)esters to 4-trifluoromethylpyrimidin-2(1H)-ones

• Sergii V. Melnykov,
• Andrii S. Pataman,
• Yurii V. Dmytriv,
• Svitlana V. Shishkina,
• Mykhailo V. Vovk and
• Volodymyr A. Sukach

Beilstein J. Org. Chem. 2017, 13, 2617–2625, doi:10.3762/bjoc.13.259

• , 4 Svobody sq, Kharkiv 61122, Ukraine 10.3762/bjoc.13.259 Abstract Background: Due to the high reactivity towards various C-nucleophiles, trifluoromethylketimines are known to be useful reagents for the synthesis of α-trifluoromethylated amine derivatives. However, decarboxylative reactions with

• , unique heterocyclic ketimines, react with malonic acid under organic base catalysis to regioselectively provide either Michael- or Mannich-type decarboxylative addition products depending on solvent polarity. Malonic mono(thio)esters give exclusively Michael-type products. The two regioisomeric products

• synthesis of novel isomeric 4(6)-trifluoromethylated 1,2,3,4-tetrahydro- and perhydro-(2-oxopyrimidin-4-yl)acetic acid derivatives. Keywords: ketimines; malonic acid; Michael- and Mannich-type decarboxylative addition; pyrimidin-2(1H)-ones; regioselectivity; trifluoromethyl group; Introduction

1-Imidoalkylphosphonium salts with modulated C_α–P⁺ bond strength: synthesis and application as new active α-imidoalkylating agents

• Jakub Adamek,
• Roman Mazurkiewicz,
• Anna Węgrzyk and
• Karol Erfurt

Beilstein J. Org. Chem. 2017, 13, 1446–1455, doi:10.3762/bjoc.13.142

• . The crucial step in the method included the decarboxylative α-methoxylation of N-phthaloyl- or N-succinylamino acids to the corresponding N-(1-methoxyalkyl)imides, followed by the displacement of the methoxy group by the triarylphosphonium group through melting of the imide derivative with

• knowledge, attempts at an electrochemical decarboxylative α-methoxylation of 2-imidoalkanecarboxylic acids have been reported only twice in the literature [33][34]. The reactions were carried out in MeOH in the presence of sodium methoxide. Unfortunately, because of the low reaction selectivity related to

• side reactions (for example Kolbe-dimerization), the yields were only poor (10–35%) [33][34]. According to our previously reported procedure for the electrochemical decarboxylative α-methoxylation of N-acyl-α-amino acids [18], amino acid derivatives 6 were converted to N-(1-methoxyalkyl)imides 7. The

Sustainable synthesis of 3-substituted phthalides via a catalytic one-pot cascade strategy from 2-formylbenzoic acid with β-keto acids in glycerol

• Lina Jia and
• Fuzhong Han

Beilstein J. Org. Chem. 2017, 13, 1425–1429, doi:10.3762/bjoc.13.139

• demand and potential for the development of a green one-pot cascade aldol/cyclization strategy for these compounds [22]. The use of β-keto acids as ketone enolate equivalents in metal- and organocatalytic decarboxylative aldol reactions has been extensively studied and proven to be a valuable and

• straightforward method for the preparation of several biologically active compounds of medicinal and agrochemical interest [23][24][25][26][27][28][29][30]. Notably, the decarboxylative reaction of β-keto acids provides a traceless means of activation with CO2 as the only byproduct. On the other hand, glycerol

Decarboxylative and dehydrative coupling of dienoic acids and pentadienyl alcohols to form 1,3,6,8-tetraenes

• Ghina’a I. Abu Deiab,
• Mohammed H. Al-Huniti,
• I. F. Dempsey Hyatt,
• Emma E. Nagy,
• Kristen E. Gettys,
• Sommayah S. Sayed,
• Christine M. Joliat,
• Paige E. Daniel,
• Rupa M. Vummalaneni,
• Andrew T. Morehead Jr,
• Andrew L. Sargent and
• Mitchell P. Croatt

Beilstein J. Org. Chem. 2017, 13, 384–392, doi:10.3762/bjoc.13.41

• at Greensboro, Greensboro, NC 27402, USA Department of Chemistry, East Carolina University, Greenville, NC 27858, USA 10.3762/bjoc.13.41 Abstract Dienoic acids and pentadienyl alcohols are coupled in a decarboxylative and dehydrative manner at ambient temperature using Pd(0) catalysis to generate

• 1,3,6,8-tetraenes. Contrary to related decarboxylative coupling reactions, an anion-stabilizing group is not required adjacent to the carboxyl group. Of mechanistic importance, it appears that both the diene of the acid and the diene of the alcohol are required for this reaction. To further understand

• materials [10][11][12][13][14][15][16][17][18]. Another approach to the formation of C–C bonds is through decarboxylative coupling reactions (Scheme 1). This can be arrived in a one-component fashion via the removal of CO2 from an ester or in a two-component manner by removal of CO2 from a carboxylic acid

Polyketide stereocontrol: a study in chemical biology

• Kira J. Weissman

Beilstein J. Org. Chem. 2017, 13, 348–371, doi:10.3762/bjoc.13.39

• appropriate precursor from the cellular pool, a ketosynthase (KS) which extends the chain via a Claisen-like decarboxylative condensation, and a non-catalytic acyl carrier protein (ACP) to which the intermediates are covalently tethered through a phosphopantetheine prosthetic group. The modules can also

Multicomponent synthesis of spiropyrrolidine analogues derived from vinylindole/indazole by a 1,3-dipolar cycloaddition reaction

• Manjunatha Narayanarao,
• Lokesh Koodlur,
• Vijayakumar G. Revanasiddappa,
• Subramanya Gopal and
• Susmita Kamila

Beilstein J. Org. Chem. 2016, 12, 2893–2897, doi:10.3762/bjoc.12.288

• out by reacting N-alkylvinyl products 3 with azomethine ylide, generated in situ through decarboxylative condensation of ninhydrin (4) and sarcosine (5). The 1,3-dipolar cycloaddition of the ylide with the olefin 3 yielded spiropyrrolidines 7 with regiospecificity (Table 1, entries 1–4). The formation

Chemical probes for competitive profiling of the quorum sensing signal synthase PqsD of Pseudomonas aeruginosa

• Michaela Prothiwa,
• Dávid Szamosvári,
• Sandra Glasmacher and
• Thomas Böttcher

Beilstein J. Org. Chem. 2016, 12, 2784–2792, doi:10.3762/bjoc.12.277

• ]. The biosynthesis of AQs has been matter of a long-standing debate that could only recently be resolved. Although HHQ could be produced in vitro by a PqsD catalyzed “head-to-head” decarboxylative Claisen condensation of activated anthranilic acid with β-keto fatty acid derivatives [10][11], isotope

• catalyzes the condensation with malonyl-CoA to form 2-aminobenzoylacetyl-CoA. The thioesterase PqsE hydrolyses the thioester to produce 2-aminobenzoylacetate (2-ABA) [13]. The PqsBC complex finally generates HHQ or other AQs in a decarboxylative condensation reaction of 2-ABA with fatty acids loaded on PqsC

Enantioselective addition of diphenyl phosphonate to ketimines derived from isatins catalyzed by binaphthyl-modified organocatalysts

• Hee Seung Jang,
• Yubin Kim and
• Dae Young Kim

Beilstein J. Org. Chem. 2016, 12, 1551–1556, doi:10.3762/bjoc.12.149

• of organocatalysts [38][39][40][41][42][43][44][45], we have reported the catalytic asymmetric decarboxylative aldol addition reaction of isatins with benzoylacetic acids catalyzed by chiral binaphthyl-based squaramide [46]. Here we wish to report the enantioselective addition reaction of diphenyl

Biosynthesis of oxygen and nitrogen-containing heterocycles in polyketides

• Franziska Hemmerling and
• Frank Hahn

Beilstein J. Org. Chem. 2016, 12, 1512–1550, doi:10.3762/bjoc.12.148

• -hydroxytetrahydro-2H-pyran-2-one 124 is formally dehydrated by consecutive malonylation–elimination to finally give a 5,6-dihydro-2H-pyran-2-one 127 [127]. The tailoring enzyme PlmT2 was proposed to catalyse the decarboxylative elimination of malonoyl halfester 126. It is not clear, whether the initial malonylation

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

• Mohammad Haji

Beilstein J. Org. Chem. 2016, 12, 1269–1301, doi:10.3762/bjoc.12.121

• ]. The desired phosphono-substituted pyrroles were isolated in 41–87% yield under solvent and catalyst-free conditions. Kaboudin et al. described a three-component, catalyst-free decarboxylative coupling of proline (296) with aldehydes 297 and dialkyl phosphonates to afford pyrrolidinylphosphonates 300

• . Multicomponent reaction of alkanedials, acetamide and acetyl chloride in the presence of PCl3 and acetic acid. An oxidative domino three-component synthesis of polyfunctionalized pyridines. A sequential one-pot three-component synthesis of polysubstituted pyrroles. Three-component decarboxylative coupling of

Synthesis of 2-oxindoles via 'transition-metal-free' intramolecular dehydrogenative coupling (IDC) of sp² C–H and sp³ C–H bonds

• Nivesh Kumar,
• Santanu Ghosh,
• Subhajit Bhunia and
• Alakesh Bisai

Beilstein J. Org. Chem. 2016, 12, 1153–1169, doi:10.3762/bjoc.12.111

• decarboxylative protonation on 2-oxindoles bearing an benzylester or para-methoxybenzyl ester at the 3-position in presence of a catalytic amount of Pd on activated charcoal. We have also shown the direct installation of allyl, prenyl, reverse-prenyl, or geranyl groups at the 3-position of 2-oxindole using Pd

• -catalyzed decarboxylative strategies [47]. Results and Discussion We decided to use iodine as an oxidant for the synthesis of 2-oxindoles [48][49][50][51][52][53], starting from β-N-arylamido ester 3a and methyl iodide as the substrates (Table 1). An elaborate optimization study suggested that the

• reaction in the presence of iodine or NIS. We envisioned that the oxidative coupling products containing benzyl or p-methoxybenzyl ester could be effective intermediates for the synthesis of 3-monosubstituted 2-oxindoles via deprotection of the benzyl group followed by decarboxylative protonation in

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• catalysts have also been used for the synthesis of chiral 3-hydroxyoxindoles. In 2013, Pan and co-workers reported the Yb(OTf)3-catalyzed enantioselective decarboxylative addition of β-ketoacids to isatins, forming the 3-hydroxyoxindoles in excellent yields (up to 98% yield) and with high

• isatin derivatives were tolerated under these conditions. The aldol reaction of N-benzyl-5-bromoisatin with 1-thiacyclohexan-4-one and cyclohexanone gave the corresponding products with 96% and 99% ee, respectively. More recently, Kesavan and co-workers reported an asymmetric decarboxylative

• crucial for the reactivity by forming hydrogen-bond interactions with CPA. Ma and co-workers described the CPA (cat. 32)-catalyzed enantioselective decarboxylative alkylation of β-keto acids with 3-hydroxy-3-indolyloxindoles, affording the 3-functionlized 3-indolyloxindoles bearing an all-carbon

Cascade alkylarylation of substituted N-allylbenzamides for the construction of dihydroisoquinolin-1(2H)-ones and isoquinoline-1,3(2H,4H)-diones

• Ping Qian,
• Bingnan Du,
• Wei Jiao,
• Haibo Mei,
• Jianlin Han and
• Yi Pan

Beilstein J. Org. Chem. 2016, 12, 301–308, doi:10.3762/bjoc.12.32

• [18][19], decarboxylative alkenylation of cycloalkanes with aryl vinylic carboxylic acids [20][21], trifluoromethylthiolation [22], thiolation [23][24], alkenylation [25][26], dehydrogenation−olefination and esterification [27][28], radical addition/1,2-aryl migration [29], cascade alkylation