Mechanistic insights into hydroxy(tosyloxy)iodobenzene-mediated ditosyloxylation of chalcones: a DFT study

• Jai Parkash,
• Sangeeta Saini,
• Vaishali Saini,
• Omkar Bains and
• Raj Kamal

Beilstein J. Org. Chem. 2025, 21, 2703–2715, doi:10.3762/bjoc.21.208

• of the hydroxy(tosyloxy)iodobenzene (HTIB)-mediated conversion of chalcones (α,β-unsaturated carbonyl compounds) to ditosyloxy ketones is investigated. Here, at β-carbon of the chalcone, an aryl group with a para-substituent is present. Our study focuses on investigating the effect of different

• -substituents; α,β-unsaturated carbonyl compounds; Introduction Hypervalent iodine compounds exhibit a range of bonding patterns which making these compounds powerful reagents or catalysts for a number of organic transformations [1][2][3][4] – oxidation of alcohols [5], epoxidation of alkenes [6], oxidative

• -mediated ditosyloxylation of α,β-unsaturated carbonyl compounds (chalcones) bearing an aryl group at β-position (compound A) leading to formation of two possible products, that are: α-arylated β,β-ditosyloxy-substituted carbonyl compound (compound B – geminal product) and β-arylated α,β-ditosyloxy

Advances in radical peroxidation with hydroperoxides

• Oleg V. Bityukov,
• Pavel Yu. Serdyuchenko,
• Andrey S. Kirillov,
• Gennady I. Nikishin,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

• leads to the formation of the target product 139. Later, iron-catalyzed three-component reactions of α,β-unsaturated carbonyl compounds 140, aldehydes 141, and TBHP leading to α-ester-β-keto peroxides 142 have been developed (Scheme 45b) [106][107][108]. Radical coupling of arylaldehydes 144 with α,β

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• blocks or their transformation with additional components besides hydrazines is a logical entry to MCR syntheses of pyrazoles. Therefore, 1,3-dielectrophiles encompass 1,3-dicarbonyl compounds and α,β-unsaturated carbonyl compounds, including alkenoyl and alkynoyl systems, across various oxidation states

• . In cases where the α,β-unsaturated carbonyl compounds contain a heteroatom in the β-position, aromatization is triggered by elimination under redox-neutral conditions. Tasch et al. successfully coupled aryl halides with α-bromocinnamaldehyde (51) using a Masuda borylation Suzuki cross-coupling (MBSC

• . The α,β-unsaturated carbonyl compounds 60 can undergo cyclization with tosylhydrazine in situ to form pyrazoles 61 under alkaline conditions, with the tosyl group acting as a leaving group. Upon deprotonation at position 1 by a base, followed by nucleophilic substitution of halides, N-functionalized

Primary amine-catalyzed enantioselective 1,4-Michael addition reaction of pyrazolin-5-ones to α,β-unsaturated ketones

• Pooja Goyal,
• Akhil K. Dubey,
• Raghunath Chowdhury and
• Amey Wadawale

Beilstein J. Org. Chem. 2024, 20, 1518–1526, doi:10.3762/bjoc.20.136

• -covalent catalysis via bifunctional hydrogen-bonding organocatalysts. The C-4 nucleophilicity of pyrazolin-5-ones was also explored in enantioselective reactions with α,β-unsaturated carbonyl compounds through covalent catalysis with chiral amine-based catalysts; however, it has achieved limited success

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• carbonyl compounds 168 can be achieved with N-thiophthalimides 14 and diaryl disulfides 47, respectively (Scheme 73) [104]. They remarked that the presence of B2pin2 was essential in the coupling reaction of disulfides with α,β-unsaturated carbonyl compounds 168. The sulfenylation involved a 1,4-addition

• HCl-promoted 1,2-thiofunctionalization of aromatic alkenes. Coupling reaction of diazo compounds with N-sulfenylsuccinimides. Multicomponent reactions of disulfides with isocyanides and other nucleophiles. α-Sulfenylation and β-sulfenylation of α,β-unsaturated carbonyl compounds.

• , tetrahydrofuran, methanol, toluene, hexane, and n-pentane were employed, in which the products in non-polar hydrocarbon solvents like hexane and n-pentane were obtained in excellent efficiency and enantioselectivity. Song et al. found that the chemoselective α-sulfenylation and β-thiolation of α,β-unsaturated

α-(Aminomethyl)acrylates as acceptors in radical–polar crossover 1,4-additions of dialkylzincs: insights into enolate formation and trapping

• Angel Palillero-Cisneros,
• Paola G. Gordillo-Guerra,
• Fernando García-Alvarez,
• Olivier Jackowski,
• Franck Ferreira,
• Fabrice Chemla,
• Joel L. Terán and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2023, 19, 1443–1451, doi:10.3762/bjoc.19.103

• reaction of dialkylzinc reagents with α,β-unsaturated carbonyl compounds. Enolate formation by zinc radical transfer (SH2 on dialkylzinc reagents). Preparation of α-(aminomethyl)acrylate 10. Reaction of α-(aminomethyl)acrylate 10 with Et2Zn in the presence of air. Chemical correlation to determine the

• levels of chiral induction, paving the way to enantioenriched β2-amino acids and β2,2-amino acids. Keywords: β-amino acids; tandem reactions; radical–polar crossover; tert-butanesulfinamide; zinc radical transfer; Introduction Dialkylzinc reagents react in aerobic medium with a range of α,β-unsaturated

• carbonyl compounds to provide the corresponding zinc enolates (Scheme 1) [1][2]. While simple, this reaction offers attractive features: 1) it proceeds under mild conditions in the absence of any transition-metal catalyst; 2) the 1,4-addition step can be combined with condensation reactions of the zinc

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• ]. Later in 2003, Buchwald, Sadighi and Jurkauskas [47] succeeded in the application of [(IPr)CuCl] as NHC–Cu(I) complex to catalyze the conjugate reduction of α,β-unsaturated carbonyl compounds. In the decade following these initial reports, the field has blossomed and NHC–Cu(I) complexes have been

• , have also been employed in conjugate addition reactions. These reagents are less reactive than organolithium and Grignard reagents but can still add to a range of α,β-unsaturated carbonyl compounds, including enones, acrylates, and imines. In 2011 Sakaguchi and co-worker [64] accomplished the conjugate

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• α,β-unsaturated carbonyl compounds [2]. In particular, the last-mentioned method is highly synthetically relevant. This approach has the advantage of being more selective and affording more molecular complexity in one step. In addition, transition-metal catalysis allows the introduction of

Electroreductive coupling of 2-acylbenzoates with α,β-unsaturated carbonyl compounds: density functional theory study on product selectivity

• Naoki Kise and
• Toshihiko Sakurai

Beilstein J. Org. Chem. 2022, 18, 956–962, doi:10.3762/bjoc.18.95

• –carbon bond formation [1][2][3][4]. Recently, we reported the electroreductive coupling of phthalic anhydrides with α,β-unsaturated carbonyl compounds in the presence of chlorotrimethylsilane (TMSCl) and subsequent treatment with 1 M HCl to give 1,4-dihydroxynaphthalenes and 2-methyl-2,3

• -dihydronaphthalene-1,4-diones (Scheme 1) [5]. In addition, we disclosed that the electroreduction of phthalimides with α,β-unsaturated carbonyl compounds under the same conditions and subsequent treatment with trifluoroacetic acid (TFA) produced 3- and 2-substituted 4-aminonaphthalen-1-ols (Scheme 2) [6]. In this

• solvent in vacuo, the residue was purified by column chromatography on silica gel (hexanes/EtOAc) to give 95 mg of 3a [8][23] (56% yield in two steps). Electroreductive coupling of phthalic anhydrides with α,β-unsaturated carbonyl compounds and subsequent treatment with 1 M HCl (previous work

Synthetic strategies for the preparation of γ-phostams: 1,2-azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides

• Jiaxi Xu

Beilstein J. Org. Chem. 2022, 18, 889–915, doi:10.3762/bjoc.18.90

• -unsaturated carbonyl compounds as electrophiles. Interestingly, for propenal (150), besides two pairs of alkylated products 151 and 152, the second naphthyl group was alkylated by sec-butyllithium, leading to the corresponding product 153 in 5% yield. For but-3-en-2-one (154), methyl propenoate, cyclopent-2

• and C-acetylation followed by enolization of the first generated acetylated benzocyclohexadiene-fused γ-phosphinolactams 149. The results indicated that short reaction times favored O-acetylation, while long reaction times preferred C-acetylation (Scheme 25) [52]. They further investigated various α,β

New advances in asymmetric organocatalysis

• Radovan Šebesta

Beilstein J. Org. Chem. 2022, 18, 240–242, doi:10.3762/bjoc.18.28

• nitromethane to β-silyl α,β-unsaturated carbonyl compounds catalyzed by bifunctional squaramide catalysts are effective under solvent-free conditions [26]. Zhai and Du demonstrated that asymmetric [3 + 2] annulation reactions of 2-isothiocyanato-1-indanones with barbiturate-based olefins are efficiently

Solvent-free synthesis of enantioenriched β-silyl nitroalkanes under organocatalytic conditions

• Akhil K. Dubey and
• Raghunath Chowdhury

Beilstein J. Org. Chem. 2021, 17, 2642–2649, doi:10.3762/bjoc.17.177

• experiments reveal that the presence of a β-silyl group in the enones is crucial for high reactivity under the optimized reaction conditions. Keywords: β-silyl α,β-unsaturated carbonyl compounds; β-silyl nitroalkanes; chiral organosilanes; organocatalysis; solvent-free synthesis; Introduction

• nucleophiles to β-silyl α,β-unsaturated carbonyl compounds were documented as one of the straightforward and atom-economic approaches for the facile synthesis of chiral organosilanes (Scheme 1c–f) [30][31][32][33]. Recently, the aforementioned reaction under organocatalytic conditions has gained attention [34

• even with better yields while the enantiomeric excess was unperturbed. Conclusion In summary, we have outlined bifunctional squaramide-catalyzed 1,4-conjugate addition reaction of nitromethane to β-silyl α,β-unsaturated carbonyl compounds to access a series of chiral β-silyl nitroalkanes in high yields

Methodologies for the synthesis of quaternary carbon centers via hydroalkylation of unactivated olefins: twenty years of advances

• Thiago S. Silva and
• Fernando Coelho

Beilstein J. Org. Chem. 2021, 17, 1565–1590, doi:10.3762/bjoc.17.112

• reacted with electron-deficient alkenes (Giese-type addition) to form new C–C bonds in intra- and intermolecular fashions. The authors reported a great diversity of electron-deficient alkenes, including α,β-unsaturated carbonyl compounds like the usually less reactive acrylamide derivative 48c

A new and efficient methodology for olefin epoxidation catalyzed by supported cobalt nanoparticles

• Lucía Rossi-Fernández,
• Viviana Dorn and
• Gabriel Radivoy

Beilstein J. Org. Chem. 2021, 17, 519–526, doi:10.3762/bjoc.17.46

• and industrial applications [1]. Among them, allylic oxidation and olefin epoxidation constitute fundamental tools for the synthesis of homoallylic alcohols or α,β-unsaturated carbonyl compounds, and epoxides, respectively. In particular, epoxides are pivotal building blocks for the synthetic chemists

Aldehydes as powerful initiators for photochemical transformations

• Maria A. Theodoropoulou,
• Nikolaos F. Nikitas and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2020, 16, 833–857, doi:10.3762/bjoc.16.76

• with this methodology, affording the products 162l and 162m in moderate to good yield, while the products deriving from α,β-unsaturated carbonyl compounds, the products 163a–c were obtained in moderate yield (Scheme 38). Next, the authors conducted various mechanistic experiments, including

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

• B2pin2 in moderate to excellent yields [127]. 2.3 β-Borylation of α,β-unsaturated compounds The use of an inexpensive transition metal like copper as catalyst is attractive for β-borylations of α,β-unsaturated carbonyl compounds, that can then be further functionalized. In 2000, an initial report

Copper-catalyzed enantioselective conjugate reduction of α,β-unsaturated esters with chiral phenol–carbene ligands

• Shohei Mimura,
• Sho Mizushima,
• Yohei Shimizu and
• Masaya Sawamura

Beilstein J. Org. Chem. 2020, 16, 537–543, doi:10.3762/bjoc.16.50

• work of Stryker and co-workers on triphenylphosphine-stabilized copper hydride complexes [1][2], copper hydrides have been widely used for conjugate reductions of α,β-unsaturated carbonyl compounds [3]. Especially a chiral copper catalyst combined with a stoichiometric amount of a silane reagent, which

• generated copper hydride in situ, has successfully been utilized for enantioselective reactions with β,β-disubstituted α,β-unsaturated carbonyl compounds [4][5][6][7][8][9][10][11]. The pioneering work of Buchwald and co-workers on the enantioselective conjugate reduction of α,β-unsaturated esters using a

• chiral p-tol-BINAP/copper catalyst established the excellent utility of chiral bisphosphine ligands for this type of reaction [4]. Surprisingly, however, chiral ligands based on N-heterocyclic carbenes (NHCs) [12] have not been applied to the conjugate reduction of α,β-unsaturated carbonyl compounds

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• method for the enantioselective synthesis of 4,5,5-trisubstituted γ-butyrolactones 193 using an electroreductive coupling of diaryl ketones 191 with α,β-unsaturated carbonyl compounds 190 bearing chiral auxiliaries derived from imidazolidin-2-one and oxazolidine-2-ones (Scheme 60). Compound 191 underwent

In water multicomponent synthesis of low-molecular-mass 4,7-dihydrotetrazolo[1,5-a]pyrimidines

• Irina G. Tkachenko,
• Sergey A. Komykhov,
• Vladimir I. Musatov,
• Svitlana V. Shishkina,
• Viktoriya V. Dyakonenko,
• Vladimir N. Shvets,
• Mikhail V. Diachkov,
• Valentyn A. Chebanov and
• Sergey M. Desenko

Beilstein J. Org. Chem. 2019, 15, 2390–2397, doi:10.3762/bjoc.15.231

• starting material and subsequent dihydropyrimidine ring formation. The first approach [6][7] represents a two-component cyclocondensation of 5-aminotetrazole (1) as binucleophilic component and bielectrophilic α,β-unsaturated carbonyl compounds 2 (Scheme 1, reaction 1). The second method [8][9][10][11][12

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

• Xiaowei Li,
• Xiaolin Shi,
• Xiangqian Li and
• Dayong Shi

Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218

• acids. In 2014, a Cu(I/II)-catalyzed α-trifluoromethylation of α,β-unsaturated carbonyl compounds were unfolded by the Bi group (Scheme 77) [140]. The reaction was applied to a broad range of carbonyl compounds, including enones, α,β-unsaturated esters, thioesters, and amides. Notably, the authors

The LANCA three-component reaction to highly substituted β-ketoenamides – versatile intermediates for the synthesis of functionalized pyridine, pyrimidine, oxazole and quinoxaline derivatives

• Tilman Lechel,
• Roopender Kumar,
• Mrinal K. Bera,
• Reinhold Zimmer and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2019, 15, 655–678, doi:10.3762/bjoc.15.61

• obtained β-ketoenamides are alkenes with a remarkable assembly of functional groups: they are enamides, enol ethers and α,β-unsaturated carbonyl compounds at the same time. In addition, their methyl ketone subunit is required for some of the subsequent transformations, e.g., the synthesis of pyridin-4-ols

Cobalt- and rhodium-catalyzed carboxylation using carbon dioxide as the C1 source

• Tetsuaki Fujihara and
• Yasushi Tsuji

Beilstein J. Org. Chem. 2018, 14, 2435–2460, doi:10.3762/bjoc.14.221

• carboxylation of mesityl triflate (5) at 40 °C proceeded successfully, affording 6 in 77% yield (Scheme 6) Carboxylation of α,β-unsaturated nitriles and esters α,β-Unsaturated carbonyl compounds are good substrates for conjugate additions that use a catalytic amount of a metal complex and a stoichiometric

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

• examples for additions of activated (EWG-substituted) ketene 1,3-dithioacetals to α,β-unsaturated carbonyl compounds are literature known [31][32] but concepts for a versatile (metal-free) application of this reaction to starting materials lacking the EWG in α-position are still missing. Results and

• HBF4. The scope of the dithi(ol)anylium TFB addition to α,β-unsaturated carbonyl compounds In order to determine the scope of the herein presented reaction, we used compound 1c for further conversions indicating the possible challenges and aims of forthcoming projects (Scheme 5). With two selected

Rh(II)-mediated domino [4 + 1]-annulation of α-cyanothioacetamides using diazoesters: A new entry for the synthesis of multisubstituted thiophenes

• Jury J. Medvedev,
• Ilya V. Efimov,
• Yuri M. Shafran,
• Vitaliy V. Suslonov,
• Vasiliy A. Bakulev and
• Valerij A. Nikolaev

Beilstein J. Org. Chem. 2017, 13, 2569–2576, doi:10.3762/bjoc.13.253

• domino reactions of diazo compounds with intermediate formation of ylides [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Thus, it was for example shown that ammonium or oxonium ylides generated in the course of intermolecular processes can be easily trapped by ketones, imines, α,β-unsaturated

• carbonyl compounds, activated multiple bonds, or other nucleophiles to furnish heterocyclic cores [22][23][24][25][26][27][28][29][30][31][32]. Similar intramolecular transformations of intermediate ylides with several nucleophilic reaction centers in the initial substrate, are also possible. The known

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

• itaconimides, four primary adducts 5–8 could result (Scheme 5) based on the well-known fact that the heterocyclization reactions of α,β-unsaturated carbonyl compounds with dinucleophilic reagents typically begin with addition like Michael’s reaction, including heterocyclic dinucleophiles [39][40][41][42

• equivalent of C1-electrophile: R2COOH/T3P® [15], BrCN (R2 = NH2) [16], ArNCS/DCC (R2 = NHAr) [20]. Heterocyclization of 1-aminoimidazoles with 1,3-dicarbonyl or α,β-unsaturated carbonyl compounds (route B). Conditions: i) R1 = NH2, NHAlk, R2 = Ph, R3,4 = Alk, Ar, solvent-free [24], AcOH [25][26], R3 = Ph, R4