The synthesis of chiral β-naphthyl-β-sulfanyl ketones via enantioselective sulfa-Michael reaction in the presence of a bifunctional cinchona/sulfonamide organocatalyst

• Deniz Tözendemir and
• Cihangir Tanyeli

Beilstein J. Org. Chem. 2021, 17, 494–503, doi:10.3762/bjoc.17.43

• synthetic organic chemistry [22]. Thus, the SMA with thiols and α,β-unsaturated ketones are generally carried out at low temperatures and with high catalyst loading [23][24][25][26]. The studies that employ mild conditions and low catalyst loading use thiophenol derivatives or simple alkylthiols as

Recent advances in Cu-catalyzed C(sp³)–Si and C(sp³)–B bond formation

• Balaram S. Takale,
• Ruchita R. Thakore,
• Elham Etemadi-Davan and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

• -additions of cuprates derived from a silyllithium [47] to α,β-unsaturated ketones [48]. There was no effort made at that time to convert these reactions to the corresponding catalytic processes, rather, the accent was more towards using the silyl group introduced as a hydroxy group equivalent [49][50][51

• silane, 1,1,2,2-tetramethyl-1,2-diphenyldisilane, also commercially available, can be used for nucleophilic additions to α,β-unsaturated ketones. Thus, by cleaving the Si–Si bond in the presence of a Cu(I) salt, an active [Cu–Si] species is generated leading to β-silylated ketones [54]. More than a

• coordination of (t-Bu)3P to CuCl is far greater than that with the diboron species, which results in an enhancement of the catalytic activity (Scheme 65) [128]. The one-pot borylation/protodeboronation of α,β-unsaturated ketones 405 in the presence of CuBr, B2pin2 and H2O as the hydrogen source was developed

Recent advances in photocatalyzed reactions using well-defined copper(I) complexes

• Mingbing Zhong,
• Xavier Pannecoucke,
• Philippe Jubault and
• Thomas Poisson

Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42

• chlorides [20]. This ATRA reaction was carried out with various fluoroalkylsulfonyl chlorides, such as CFH2SO2Cl, CF2HSO2Cl, CF3SO2Cl, CF3CH2SO2Cl, and C4F9SO2Cl, electron-deficient alkenes, including α,β-unsaturated ketones, amides, esters, carboxylic acids, sulfones, and phosphonates (Scheme 4). In

Copper-promoted/copper-catalyzed trifluoromethylselenolation reactions

• Clément Ghiazza and
• Anis Tlili

Beilstein J. Org. Chem. 2020, 16, 305–316, doi:10.3762/bjoc.16.30

• carbonyl compounds with [(bpy)CuSeCF3]2 by the group of Weng. Trifluoromethylselenolation of α,β-unsaturated ketones with [(bpy)CuSeCF3]2 by the group of Weng. Trifluoromethylselenolation of acid chlorides with [(bpy)CuSeCF3]2 by the group of Weng. Synthesis of 2-trifluoromethylselenylated benzofused

Ultrasonic-assisted unusual four-component synthesis of 7-azolylamino-4,5,6,7-tetrahydroazolo[1,5-a]pyrimidines

• Yana I. Sakhno,
• Maryna V. Murlykina,
• Oleksandr I. Zbruyev,
• Anton V. Kozyryev,
• Svetlana V. Shishkina,
• Dmytro Sysoiev,
• Vladimir I. Musatov,
• Sergey M. Desenko and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2020, 16, 281–289, doi:10.3762/bjoc.16.27

• α,β-unsaturated ketones [8][9][10][11] or via their multicomponent analogues. On the other hand, multicomponent reactions (MCRs) directly leading to tetrahydroazolopyrimidine heterocyclic systems have also been published [4][5][16][17][18][19][20][21][22][23][24]. In particular, multicomponent

Copper-catalyzed enantioselective conjugate addition of organometallic reagents to challenging Michael acceptors

• Delphine Pichon,
• Jennifer Morvan,
• Christophe Crévisy and
• Marc Mauduit

Beilstein J. Org. Chem. 2020, 16, 212–232, doi:10.3762/bjoc.16.24

• , and Grignard reagents to Michael acceptors. In that respect, since the pioneering example reported by Alexakis and co-workers in 1993 [5], a wide range of cyclic and acyclic electron-deficient alkenes, such as α,β-unsaturated ketones, esters, nitriles, sulfones, or nitroolefines, was intensively

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

• was synthesized considering ketones having ED and EWGs, with sensitive –NO2 groups along with heteroaromatic ketones as well as α,β-unsaturated ketones. Differently substituted compound 3 (except –NO2 substitution) gave moderate to good yields (55–84%). Moreover, the protocol has demonstrated the

• reaction has well tolerated differently substituted ketones, with lack of product in case of ortho-substitution due to steric hinderance. Similarly, substituted 2-APs provided a library of compounds with god yield, however, α,β-unsaturated ketones, such as benzalacetone, did not afford any desired product

DABCO- and DBU-promoted one-pot reaction of N-sulfonyl ketimines with Morita–Baylis–Hillman carbonates: a sequential approach to (2-hydroxyaryl)nicotinate derivatives

• Soumitra Guin,
• Raman Gupta,
• Debashis Majee and
• Sampak Samanta

Beilstein J. Org. Chem. 2018, 14, 2771–2778, doi:10.3762/bjoc.14.254

• -dicarbonyl compounds, and ammonium acetate promoted by acid under aerobic conditions [37][38]. Furthermore, Brønsted- and Lewis-acid-catalyzed cyclization reactions between β-enamino esters (derived from β-ketoesters and ammonium acetate) and alkynones/α,β-unsaturated carbonyls/in situ generated α,β

• -unsaturated ketones (from alkyl ketones) as Michael acceptors to construct a diverse set of nicotinate derivatives were developed by Bohlman–Rahtz [39], Bagley [40][41] and other groups independently [42][43][44][45][46][47][48][49][50][51][52][53][54][55]. Similarly, the synthesis of functionalized

A challenging redox neutral Cp*Co(III)-catalysed alkylation of acetanilides with 3-buten-2-one: synthesis and key insights into the mechanism through DFT calculations

• Andrew Kenny,
• Alba Pisarello,
• Arron Bird,
• Paula G. Chirila,
• Alex Hamilton and
• Christopher J. Whiteoak

Beilstein J. Org. Chem. 2018, 14, 2366–2374, doi:10.3762/bjoc.14.212

• few examples do exist using the [Cp*Co(CO)I2] pre-catalyst [14][15][16][17]. Cp*Co(III)-catalysed C–H alkylation of unactivated aromatic C–H bonds with α,β-unsaturated ketones has been previously reported by ourselves (Scheme 1a) [18] and others [19][20]. Given our example focusing on the

Addition of dithi(ol)anylium tetrafluoroborates to α,β-unsaturated ketones

• Yu-Chieh Huang,
• An Nguyen,
• Simone Gräßle,
• Sylvia Vanderheiden,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2018, 14, 515–522, doi:10.3762/bjoc.14.37

• Technology, Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany 10.3762/bjoc.14.37 Abstract In the presented study, dithi(ol)anylium tetrafluoroborates are added to α,β-unsaturated ketones in a Michael-type reaction yielding diverse substituted ketene diothi(ol)anes. The reactions proceed at room temperature in 1

• work of others [30], they allow the addition of electrophiles in α-position independent of further presence of activating electron-withdrawing groups (EWGs). In the present study we will show the successful use of dithi(ol)anylium TFBs for the Michael-type addition to α,β-unsaturated ketones. A few

• Discussion Addition to α,β-unsaturated ketones Since we could show the benefits of a use of dithi(ol)anylium TFBs instead of ketene 1,3-dithioacetals for the addition of diazo components [31], we were interested in a more general use of dithi(ol)anylium TFBs for the addition to electrophiles in α-position to

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

• Ranjana Aggarwal and
• Suresh Kumar

Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15

• ) and α,β-unsaturated ketones 24 (Scheme 3) in the ionic solvent [bmim]Br at 90 °C with excellent yield. Variation of the aryl substituents on the α,β-unsaturated ketones 24 has no significant effect on the reaction. The reaction was proposed to occur through a sequence of Michael addition, cyclization

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

• desired product 54 trans-selectively (Scheme 30). In 2016, Xia and co-workers described a metal-free, UV-light-mediated difunctionalisation of alkenes with CF3SO2Na for the synthesis of phenanthrene and anthrone derivatives [53]. The substrates were either α,β-unsaturated ketones 57 (Scheme 31a) or γ,δ

A novel synthetic approach to hydroimidazo[1,5-b]pyridazines by the recyclization of itaconimides and HPLC–HRMS monitoring of the reaction pathway

• Dmitry Yu. Vandyshev,
• Khidmet S. Shikhaliev,
• Andrey Yu. Potapov,
• Michael Yu. Krysin,
• Fedor I. Zubkov and
• Lyudmila V. Sapronova

Beilstein J. Org. Chem. 2017, 13, 2561–2568, doi:10.3762/bjoc.13.252

• [1,5-b]pyridazines along route B, 1-aminoimidazoles with no substituents at the C-5 atom of the original heterocycle and 1,3-dielectrophilic reagents are used, e.g., 1,3-diketones [24][25][26], β-ketoesters [24], α,β-unsaturated ketones [27][28], including those obtained in situ [29][30] or containing

Preparation of imidazo[1,2-a]-N-heterocyclic derivatives with gem-difluorinated side chains

• Layal Hariss,
• Kamal Bou Hadir,
• Mirvat El-Masri,
• Thierry Roisnel,
• René Grée and
• Ali Hachem

Beilstein J. Org. Chem. 2017, 13, 2115–2121, doi:10.3762/bjoc.13.208

• (II) acetate-catalyzed aerobic oxidative amination and it proceeds through a tandem Michael addition followed by an intramolecular oxidative amination. Therefore, our target molecules A could be synthesized by the oxidative coupling of 2-aminopyridines with α,β-unsaturated ketones B, themselves easily

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• bases like NaOH, KOH, NaOEt etc. have been used as catalyst for the Michael addition of 1,3-dicarbonyl compounds to α,β-unsaturated ketones. In 2004, Wang and co-workers first reported a mechanochemical Michael reaction of 1,3-dicarbonyl compounds with chalcones and azachalcones using the mild base

Base-promoted isomerization of CF₃-containing allylic alcohols to the corresponding saturated ketones under metal-free conditions

• Yoko Hamada,
• Tomoko Kawasaki-Takasuka and
• Takashi Yamazaki

Beilstein J. Org. Chem. 2017, 13, 1507–1512, doi:10.3762/bjoc.13.149

• We have previously reported [1][2][3] an extremely efficient isomerization process of γ-trifluoromethylated propargylic alcohols 1F to the corresponding α,β-unsaturated ketones (E)-5 by the action of a weak base like Et3N under THF reflux conditions (Scheme 1). From the mechanistic point of view

• by way of the latter intermediate would be occurred at the CF3-attached carbon atom to produce the corresponding allenyl type intermediate. Furthermore, its keto–enol interconversion would result in construction of the isomerized α,β-unsaturated ketones (E)-5 [4][5][6]. For a better comprehension of

• pm was found to be only 2.4 pm longer than the same bond in protonated DABCO which would be one of the major reasons why the weaker base Et3N did not work for this reaction. Conclusion As shown above, our original isomerization of CF3-containing propargylic alcohols 1F to the corresponding α,β

Synthesis and enzymatic ketonization of the 5-(halo)-2-hydroxymuconates and 5-(halo)-2-hydroxy-2,4-pentadienoates

• Tyler M. M. Stack,
• William H. Johnson Jr. and
• Christian P. Whitman

Beilstein J. Org. Chem. 2017, 13, 1022–1031, doi:10.3762/bjoc.13.101

• is the thermodynamically stable one (≈80% at equilibrium) and the substrate for 4-OD, which is the next enzyme in the pathway (Scheme 1). The kinetic analysis for the ketonization of 3b–d to 4b–d is complicated by the much lower amounts of the α,β-unsaturated ketones present at equilibrium and the

• 3a–d and 5a–d by Pp and Lc 4-OT Previous work has shown that 4-OT partitions a host of dienols to their β,γ- and α,β-unsaturated ketones [16][17]. The behavior of 5b–d is consistent with these observations. The steady state kinetic parameters for the Pp 4-OT-catalyzed conversion of 5b–d to the β,γ

• -unsaturated ketones (11b–d, respectively) and α,β-unsaturated ketones (9b,c, respectively) were determined, and compared to those for the non-halogenated species (5a to 11a and 5a to 9a) (Table 4). For ketonization to the β,γ-unsaturated ketones, the kcat/Km values are comparable ranging from 2.3 × 105 (5

Transition-metal-free one-pot synthesis of alkynyl selenides from terminal alkynes under aerobic and sustainable conditions

• Adrián A. Heredia and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2017, 13, 910–918, doi:10.3762/bjoc.13.92

• presence of Pd and Cu catalysts to afford (E)-α-selenylstannanes for the synthesis of trisubstituted alkenes [13] and hydrozirconation with further replacement of Zr atom by hydrogen or halogen [14] or their use in the preparation of α-seleno-α,β-unsaturated ketones [15]. Besides, hydrogen halide-addition

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• their synthesis (Figure 2). The commonly used reaction in this area is the Nazarov reaction which employs α,β-unsaturated ketones as substrates and is carried out in the presence of Brønsted or Lewis acids. Despite extensive studies on 1-indanones and their biological activity, this group of compounds

• 55 via a formal 1,4-addition of arylboronic acids to β-aryl-α,β-unsaturated ketones and esters [39]. Thus, the α,β-unsaturated diester 52 was coupled with arylboronic acid in the presence of rhodium(I)/Chiraphos® complex as a catalyst to obtain derivative 53, which next underwent a Claisen

• 116 was isolated in 60% yield and further used in the synthesis of the natural product. Hexamethylenetetramine (HMTA) is a commonly used promoter of aryl alkyl ketones in the Mannich reaction which has been applied in the synthesis of α,β-unsaturated ketones 119 [64]. The HMTA/acetic anhydride

Synthesis of polyhydroxylated decalins via two consecutive one-pot reactions: 1,4-addition/aldol reaction followed by RCM/syn-dihydroxylation

• Michał Malik and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2016, 12, 2602–2608, doi:10.3762/bjoc.12.255

• possibility of using a copper-catalyzed one-pot 1,4-addition of vinylmagnesium bromide to sugar-derived cyclic α,β-unsaturated ketones (such as 9), followed by an aldol reaction with an optically pure derivative of but-2-enal 10 to obtain a mixture of diastereomeric dienes, such as 11 (Scheme 2). As a result

• of this transformation, three new stereogenic centers are generated. A copper-catalyzed 1,4-addition of organometallic reagents to cyclic α,β-unsaturated ketones, followed by an aldol reaction has been already used in the synthesis of complex natural products [26][27][28][29][30][31][32][33

• ]. After desilylation followed by protection of the free hydroxy with a benzoyl group and deprotection of the isopropylidene moiety, diols 20 and 24 were obtained. With α,β-unsaturated ketones 17 and 18 and two enantiomeric, optically pure aldehydes (R)- and (S)-10 in hand, we started to study the 1,4

β-Amino functionalization of cinnamic Weinreb amides in ionic liquid

• Yi-Ning Wang,
• Guo-Xiang Sun and
• Gang Qi

Beilstein J. Org. Chem. 2016, 12, 2372–2377, doi:10.3762/bjoc.12.231

• reaction conditions required for the removal of the N-protecting groups. With the aminochlorination developed in the past few years [31], we found that when the aminochlorination reactions of α,β-unsaturated ketones 3 were carried out in ionic liquid, [BMIM][NTf2] (1-n-butyl-3-methylimidazolium bis

• , when the ionic liquid [BMIM][BF4] was utilized as the reaction media, no anticipated haloamine products were detected, which was similar to the aminochlorination of α,β-unsaturated ketones [32]. Fortunately, when we switched the ionic liquid to [BMIM][NTf2], it was found that the starting material, N

• atoms of not only the syn-stereoisomers but also the β-amino compounds derived from α,β-unsaturated ketones. This hypothesis can be supported by an unexpected transformation. When aziridine 7-B was purified by flash column chromatography, part of the aziridine ring was opened by a chlorine anion to form

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• for 24 h (Scheme 12) [230]. Oxone is a convenient reagent for the transformation of α,β-unsaturated ketones 43 of determined stereochemistry into vinyl acetates 44 via the Baeyer–Villiger reaction in dry DMF for 7–39 h (Scheme 13) [231]. Oxidation with H2O2–heteroorganic catalyst systems: The activity

• benzeneseleninoperoxoic anhydride [PhSe(O)O]2O in the first step, which then transforms to the active oxidant benzeneseleninoperoxoic acid PhSe(O)OOH [233]. The Baeyer–Villiger oxidation of (E)-α,β-unsaturated ketones to (E)-vinyl esters was performed with hydrogen peroxide and dibenzyl diselenide as pre-catalyst at room

Conjugate addition–enantioselective protonation reactions

• James P. Phelan and
• Jonathan A. Ellman

Beilstein J. Org. Chem. 2016, 12, 1203–1228, doi:10.3762/bjoc.12.116

• substituent was aliphatic, good enantioselectivity was observed (87.5:12.5 to 96:4 er); however, aromatic and piperonyl groups greatly diminished the enantioselectivity of the transformation (63.5:36.5 to 73:27 er). α,β-Unsaturated ketones Lewis acids In 2012, Kobayashi and co-workers reported the Sc

• -catalyzed enantioselective addition of benzylic thiols 104 to α,β-unsaturated ketones 105 (Scheme 25a) [50]. Interestingly, water was found to be the optimal solvent for this transformation, switching to organic solvents (CH2Cl2, THF, toluene) resulted in diminished reactivity and poor enantioselectivity

• thiols to N-arylitaconimides. Enantioselective addition of thiols to α-substituted N-acryloylamides. Kobayashi’s enantioselective addition of thiols to α,β-unsaturated ketones. Feng’s enantioselective addition of pyrazoles to α-substituted vinyl ketones. Luo and Cheng’s addition of indoles to vinyl

Study on the synthesis of the cyclopenta[f]indole core of raputindole A

• Nils Marsch,
• Mario Kock and
• Thomas Lindel

Beilstein J. Org. Chem. 2016, 12, 334–342, doi:10.3762/bjoc.12.36

• reactions with α,β-unsaturated ketones to obtain indanones and dihydronaphthones [39][40]. Aminophenol 9 was converted to iodophenol 10 in good yield through a Sandmeyer reaction (Scheme 3) [41]. Various nitration conditions were tested, yet only the use of concentrated HNO3 in CH2Cl2, as reported by

New metathesis catalyst bearing chromanyl moieties at the N-heterocyclic carbene ligand

• Agnieszka Hryniewicka,
• Szymon Suchodolski,
• Agnieszka Wojtkielewicz,
• Jacek W. Morzycki and
• Stanisław Witkowski

Beilstein J. Org. Chem. 2015, 11, 2795–2804, doi:10.3762/bjoc.11.300

• -deficient olefin (e.g., acrylates or acrylonitriles, type II or III). In these cases, full conversion and high yields can be achieved [18]. Although the problem with the CM reactions of olefins with electron-withdrawing groups, such as α,β-unsaturated ketones and esters, is partly solved [19][20], the