Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13

• works, the oxidative coupling of alcohols, aldehydes, or formamides with 1,3-dicarbonyl compounds or phenols was accomplished in the presence of tert-butyl hydroperoxide and copper salts (Table 5). In most cases, the range of phenols applicable to the coupling is limited to 2-acylphenols. However, 2

• salts, were used for the oxidative functionalization at the α-position of carbonyl compounds. N-Hydroxyimides and N-hydroxyamides 204 are involved in the oxidative C–O coupling with 1,3-dicarbonyl compounds and their hetero analogues, such as 2-substituted malononitriles and cyanoacetic esters, 205 in

• radicals 207 from N-hydroxyimides or N-hydroxyamides 204 and the one-electron oxidation of 1,3-dicarbonyl compounds via the formation of complex 208. Apparently, the oxidative coupling of 1,3-dicarbonyl compounds 209 with oximes 210 occurs via a similar mechanism [198]. The reaction takes place in the

Three-component synthesis of C₂F₅-substituted pyrazoles from C₂F₅CH₂NH₂·HCl, NaNO₂ and electron-deficient alkynes

• Pavel K. Mykhailiuk

Beilstein J. Org. Chem. 2015, 11, 16–24, doi:10.3762/bjoc.11.3

• -dicarbonyl compounds (or their synthons) with hydrazines [39][40][41][42][43][44]. In this context, novel practical methods to C2F5-pyrazoles are needed. Last year, Ma and colleagues synthesized CF3-pyrazoles by [3 + 2] cycloaddition between in situ generated CF3CHN2 and alkynes [45]. This method, however

• including several drugs contain a C2F5 group (Figure 2) [34][35][36]. The conceptually attractive C2F5-pyrazoles [37], however, still remain somewhat in the shadow [38], probably because of the lack of the corresponding chemical approaches. Predominantly, C2F5-pyrazoles are synthesized by a reaction of 1,3

Recent advances in the electrochemical construction of heterocycles

• Robert Francke

Beilstein J. Org. Chem. 2014, 10, 2858–2873, doi:10.3762/bjoc.10.303

• generated 1,2-benzoquinones via sequential Michael addition/ring closure An electrochemical method for the synthesis of benzofuran and indol derivatives is based on the oxidation of catechol in presence of 1,3-dicarbonyl compounds or analogous C,H-acidic compounds 62 (Scheme 24) [69][70][71][72]. The

• indole derivatives. Anodic anellation of catechol derivatives 66 with different 1,3-dicarbonyl compounds. Electrosynthesis of 1,2-fused indoles from catechol and ketene N,O-acetals. Reaction of N-acyliminium pools with olefins having a nucleophilic substituent. Synthesis of thiochromans using the cation

(CF₃CO)₂O/CF₃SO₃H-mediated synthesis of 1,3-diketones from carboxylic acids and aromatic ketones

• JungKeun Kim,
• Elvira Shokova,
• Victor Tafeenko and
• Vladimir Kovalev

Beilstein J. Org. Chem. 2014, 10, 2270–2278, doi:10.3762/bjoc.10.236

• syntheses of 1,3-diketones and pyrazoles directly from acids and ketones. Moreover, 1,3-diketones and pyrazoles can be obtained from unmodified β-phenylpropionic acids. Given the importance of 1,3-dicarbonyl compounds in general, we expect that this reaction has a wide application in the realm of synthetic

Multicomponent reactions in nucleoside chemistry

• Mariola Koszytkowska-Stawińska and
• Włodzimierz Buchowicz

Beilstein J. Org. Chem. 2014, 10, 1706–1732, doi:10.3762/bjoc.10.179

• system (Scheme 27) [98][99]. Attempts to replace the aldehyde 73a with its 3,4,6-hydroxylated counterpart failed to give the expected product [99]. Dwivedi et al. showed that the isopropylidene-protected sugars 75 reacted efficiently with urea (or thiourea) and 1,3-dicarbonyl compounds in diethylene

• The classical Hantzsch reaction provides 1,4-dihydropyrimidines (1,4-DHPs) from 1,3-dicarbonyl compounds, aldehydes and ammonia (Scheme 32) [19]. The reaction has attracted a considerable attention because of the therapeutic usefulness of drugs featuring the 1,4-DHP scaffold, i.e., nifedipine and

Less reactive dipoles of diazodicarbonyl compounds in reaction with cycloaliphatic thioketones – First evidence for the 1,3-oxathiole–thiocarbonyl ylide interconversion

• Valerij A. Nikolaev,
• Alexey V. Ivanov,
• Ludmila L. Rodina and
• Grzegorz Mlostoń

Beilstein J. Org. Chem. 2013, 9, 2751–2761, doi:10.3762/bjoc.9.309

• agreement with the other data reported for the analogous 1,3-oxathioles bearing the spiroadamantane skeleton [5][14]. Hence, the main products of the reactions of thioketones 1a,b with deactivated dipoles of the acyclic 2-diazo-1,3-dicarbonyl compounds 2a–g were 1,3-oxathioles 3 and 7. The mechanisms of the

• prepared from the corresponding 1,3-dicarbonyl compounds and arenesulfonyl azides by diazo-transfer reactions [18]. Thioketones 1a,b were prepared from the corresponding ketones by known procedures [15][16]. General procedure for the reaction of diazodicarbonyl compounds with thioketone 1a: A mixture of

• diazoalkanes, diazoesters and diazoketones [1][2][3][4]. Due to their high dipolarophilic reactivity thioketones were given the name ‘superdipolarophiles’ [3][4]. It might be expected that these highly reactive dipolarophiles could also easily react with the deactivated 1,3-dipoles of 2-diazo-1,3-dicarbonyl

Mechanistic studies on the CAN-mediated intramolecular cyclization of δ-aryl-β-dicarbonyl compounds

• Brian M. Casey,
• Dhandapani V. Sadasivam and
• Robert A. Flowers II

Beilstein J. Org. Chem. 2013, 9, 1472–1479, doi:10.3762/bjoc.9.167

• -tetralone product 2a (Scheme 1) [15]. Using this method, a variety of 1,3-dicarbonyl compounds can be mildly converted to carboxylic acids in moderate to excellent yields. In follow up studies, we found that 2-tetralone 2a could be obtained as the major product when 1a was oxidized by CAN in MeOH [16]. In

• carbonyl groups anti to each other. For TS1a’ the dihedral angle between atoms abcd = 6.4°. *The energy values for 1a’, 1g’, 1h’ and 1j’ are shown. 1g”, 1f’ and 1j” were not included for clarity. Possible products from the ortho cyclization of 1g and 1j. Oxidative conversion of 1,3-dicarbonyl compounds to

Tandem dinucleophilic cyclization of cyclohexane-1,3-diones with pyridinium salts

• Mostafa Kiamehr,
• Firouz Matloubi Moghaddam,
• Satenik Mkrtchyan,
• Volodymyr Semeniuchenko,
• Linda Supe,
• Alexander Villinger,
• Peter Langer and
• Viktor O. Iaroshenko

Beilstein J. Org. Chem. 2013, 9, 1119–1126, doi:10.3762/bjoc.9.124

• dielectrophiles has been a major research subject in both our laboratories. For example, we have studied reactions of quinolinium [36][37], isoquinolinium [38][39][40], quinazolinium [41][42] and quinoxalinium [43] salts with 1,3-bis(silyl enol ethers), i.e., masked 1,3-dicarbonyl compounds, which provided facile

Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

• Yan Sun,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 8–14, doi:10.3762/bjoc.9.2

• describing that either 2-naphthylamine [22][23][24][25], functionalized 5-aminopyrazoles [26][27][28], or 2-aminobenzothiazoles [29] reacted with isatin and cyclic 1,3-dicarbonyl compounds to give the similar spiro[dihydropyridine-oxindole] (II, III in Figure 2), in which both the amino group and the aryl

• condensation of isatins with cyclic 1,3-dicarbonyl compounds [30][31][32][33], the condensation reaction of isatin with cyclopentane-1,3-dione seemed still not to have been investigated and the 3,3-bis(2-hydroxy-5-oxo-cyclopent-1-enyl)oxindoles 3a–3d have not been prepared until now. Thus, the direct

Synthesis and evaluation of new guanidine-thiourea organocatalyst for the nitro-Michael reaction: Theoretical studies on mechanism and enantioselectivity

• Tatyana E. Shubina,
• Matthias Freund,
• Sebastian Schenker,
• Timothy Clark and
• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2012, 8, 1485–1498, doi:10.3762/bjoc.8.168

• not considered for the further studies. A similar Michael reaction of 1,3-dicarbonyl compounds with nitroolefins has been studied in some detail before [57][59]. It is generally proposed that the reaction proceeds first by deprotonation of the acidic proton of malonate 14 followed by formation of a

Organocatalytic asymmetric addition of malonates to unsaturated 1,4-diketones

• Sergei Žari,
• Tiiu Kailas,
• Marina Kudrjashova,
• Mario Öeren,
• Ivar Järving,
• Toomas Tamm,
• Margus Lopp and
• Tõnis Kanger

Beilstein J. Org. Chem. 2012, 8, 1452–1457, doi:10.3762/bjoc.8.165

• , the increase in temperature resulted in a small drop in stereoselectivity for the model reaction with catalyst VII. The mechanism of the reaction is believed to be similar to that previously reported for 1,3-dicarbonyl compounds and acyl phosphonates [23]. Squaramide IX is a bifunctional catalyst that

Synthesis of chiral sulfoximine-based thioureas and their application in asymmetric organocatalysis

• Marcus Frings,
• Isabelle Thomé and
• Carsten Bolm

Beilstein J. Org. Chem. 2012, 8, 1443–1451, doi:10.3762/bjoc.8.164

• organic transformations with hydrogen bond accepting substrates. Recently, we reported the enantioselective ring opening of cyclic meso-anhydrides and asymmetric Michael additions of 1,3-dicarbonyl compounds to nitroalkenes with thiourea-based organocatalysts [48][49]. Based on those studies and in the

Synthesis of diverse indole libraries on polystyrene resin – Scope and limitations of an organometallic reaction on solid supports

• Kerstin Knepper,
• Sylvia Vanderheiden and
• Stefan Bräse

Beilstein J. Org. Chem. 2012, 8, 1191–1199, doi:10.3762/bjoc.8.132

• ], palladium-catalyzed indole synthesis [34][35][36][37][38][39][40], cycloaddition strategies [41], C-arylation of substituted acetonitriles or 1,3-dicarbonyl compounds [42], halocyclization [43][44] and finally, reduction of ortho-fluoro-nitroarenes [42]. The significant biological properties and the

Expanding the chemical diversity of spirooxindoles via alkylative pyridine dearomatization

• Chunhui Dai,
• Bo Liang and
• Corey R. J. Stephenson

Beilstein J. Org. Chem. 2012, 8, 986–993, doi:10.3762/bjoc.8.111

• ]oxazino derivatives from N-substituted isatins and 1,3-dicarbonyl compounds with pyridine derivatives is reported. The reactions provided good to excellent yields. Further exploration of the molecular diversity of these compounds is demonstrated through Diels–Alder reactions. Keywords: chemical diversity

• ; 1,3-dicarbonyl compounds; Diels–Alder reaction; molecular diversity; pyridine dearomatization; spirooxindole; Introduction The spirooxindole is a common structural motif found in a variety of complex alkaloids [1]. Many compounds that possess a spirooxindole moiety exhibit significant biological

• ], we previously reported a Lewis acid catalyzed, three-component synthesis of spirooxindole pyranochromenedione derivatives using isatin and two 1,3-dicarbonyl compounds (Scheme 1) [14]. Mechanistically, we believed this reaction to proceed through an intermediate isatylidene 1 [15][16][17]. As a means

Enantioselective Michael addition of 2-hydroxy-1,4-naphthoquinones to nitroalkenes catalyzed by binaphthyl-derived organocatalysts

• Saet Byeol Woo and
• Dae Young Kim

Beilstein J. Org. Chem. 2012, 8, 699–704, doi:10.3762/bjoc.8.78

• to the development of asymmetric conjugate additions of 1,3-dicarbonyl compounds to various Michael acceptors [27][28][29][30][31][32][33]. Recently, the groups of Du and Zhou reported a highly enantioselective Michael addition of 2-hydroxy-1,4-naphthoquinones to nitroalkenes catalyzed by chiral

Catalyst-free and solvent-free Michael addition of 1,3-dicarbonyl compounds to nitroalkenes by a grinding method

• Zong-Bo Xie,
• Na Wang,
• Ming-Yu Wu,
• Ting He,
• Zhang-Gao Le and
• Xiao-Qi Yu

Beilstein J. Org. Chem. 2012, 8, 534–538, doi:10.3762/bjoc.8.61

• , East China Institute of Technology, Fuzhou, China, 344000; Fax: (+86)794-8258320; Tel:(+86)794-8258320 10.3762/bjoc.8.61 Abstract An environmentally benign, fast and convenient protocol has been developed for the Michael addition of 1,3-dicarbonyl compounds to β-nitroalkenes in good to excellent

• method. Herein, we report a green protocol for the Michael addition of 1,3-dicarbonyl compounds to nitroalkenes under catalyst- and solvent-free conditions (Scheme 1). Utilizing this simple, rapid, low-cost and effective procedure, various nitro diketone derivatives were synthesized in high yields

• were used as the acceptors to react with 1,3-dicarbonyl compounds under the optimized conditions. The results are given in Table 1. It can be seen that a wide range of substrates were able to participate in the reaction. A series of substituted β-nitrostyrenes with electron-withdrawing or electron

Regioselectivity in the multicomponent reaction of 5-aminopyrazoles, cyclic 1,3-diketones and dimethylformamide dimethylacetal under controlled microwave heating

• Kamal Usef Sadek,
• Ramadan Ahmed Mekheimer,
• Tahany Mahmoud Mohamed,
• Moustafa Sherief Moustafa and
• Mohamed Hilmy Elnagdi

Beilstein J. Org. Chem. 2012, 8, 18–24, doi:10.3762/bjoc.8.3

• 50918, Jeddah 21533, Kingdom of Saudi Arabia Chemistry Department, Faculty of Science, Kuwait University, PO Box 5969, Safat, 13060 Kuwait 10.3762/bjoc.8.3 Abstract The multicomponent reaction of 5-aminopyrazole derivatives with cyclic 1,3-dicarbonyl compounds and dimethylformamide dimethylacetal

Efficient synthesis of 1,3-diaryl-4-halo-1H-pyrazoles from 3-arylsydnones and 2-aryl-1,1-dihalo-1-alkenes

• Yiwen Yang,
• Chunxiang Kuang,
• Hui Jin,
• Qing Yang and
• Zhongkui Zhang

Beilstein J. Org. Chem. 2011, 7, 1656–1662, doi:10.3762/bjoc.7.195

• based on the condensation of hydrazines with 1,3-dicarbonyl compounds or their equivalents. However, the 1,3-dipolar cycloaddition offers a more convenient synthetic route. Sydnones are easily accessible aromatic compounds and versatile synthetic intermediates. They can be used as unusual, alternative

Hypervalent iodine(III)-induced methylene acetoxylation of 3-oxo-N-substituted butanamides

• Wei-Bing Liu,
• Cui Chen,
• Qing Zhang and
• Zhi-Bo Zhu

Beilstein J. Org. Chem. 2011, 7, 1436–1440, doi:10.3762/bjoc.7.167

• , the reactions of other N-(alkylsubstituted)-3-oxobutanamides were investigated, such as that of N-methyl-3-oxobutanamide (1l), which led to 1-(methylcarbamoyl)-2-oxopropyl acetate in 89% yield. Furthermore, we applied this method to non-carbamoyl 1,3-dicarbonyl compounds. These substrates, namely 1

Development of the titanium–TADDOLate-catalyzed asymmetric fluorination of β-ketoesters

• Lukas Hintermann,
• Mauro Perseghini and
• Antonio Togni

Beilstein J. Org. Chem. 2011, 7, 1421–1435, doi:10.3762/bjoc.7.166

• ketones in the presence of antimony chloride have appeared [59], while Umemoto used Lewis acids in substoichiometric amounts (0.4 equiv of ZnCl2 or AlCl3) to accelerate fluorinations of 1,3-dicarbonyl compounds with N-fluoropyridinium salts [72]. In 1998, Chambers and Hutchinson reported the reaction of

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

• that it is more environmentally friendly [4][5][8][9]. Among the various known multicomponent reactions, the MCRs that involve 1,3-dicarbonyl compounds, aldehydes, and nucleophilic compounds have received particular interest in recent years owing to their potential to provide different condensation

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

• -arylhydroxylamines with 1,3-dicarbonyl compounds in situ) to give 3-carbonylated benzofuran derivatives 300 [153]. Trisubstituted isoxazoles 303 were obtained from alkynyl oxime ether 301 through a gold-catalyzed domino reaction involving cyclization and subsequent Claisen-type rearrangement [154]. The presence of

One-pot gold-catalyzed synthesis of 3-silylethynyl indoles from unprotected o-alkynylanilines

• Jonathan P. Brand,
• Clara Chevalley and
• Jérôme Waser

Beilstein J. Org. Chem. 2011, 7, 565–569, doi:10.3762/bjoc.7.65

• -alkynylanilines can be followed by 1,4-addition to enones [15][16], iodination [17] or reaction with 1,3-dicarbonyl compounds [18]. Perumal recently demonstrated that aldehydes and nitroalkenes can be used as electrophilic partners [19][20]. Triple bonds can also serve as a second electrophile for the

A review of new developments in the Friedel–Crafts alkylation – From green chemistry to asymmetric catalysis

• Magnus Rueping and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2010, 6, No. 6, doi:10.3762/bjoc.6.6

• benzylation of arenes and heteroarenes. A gold(III)-catalyzed route to beclobrate. Catalytic FC-type alkylations of 1,3-dicarbonyl compounds. Iron(III)-catalyzed synthesis of phenprocoumon. Bi(OTf)3-catalyzed FC alkylation of benzyl alcohols developed by Rueping et al. (A) Bi(OTf)3-catalyzed intramolecular FC