Methodology for awakening the potential secondary metabolic capacity in actinomycetes

• Shun Saito and
• Midori A. Arai

Beilstein J. Org. Chem. 2024, 20, 753–766, doi:10.3762/bjoc.20.69

• , ytterbium (Yb), but not in the presence of other metals. Structural analyses revealed that this pigment is a type of naphthoquinone similar to nanaomycin (24) [64]. Furthermore, Tanaka et al. showed that low concentrations of the rare earth elements scandium (Sc) and/or lanthanum (La) markedly activate (2.5

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

• N-(sulfenyl)succinimide/phthalimide in chemical syntheses will be widely seen in the future. Sulfur-containing bioactive molecules. Scandium-catalyzed synthesis of thiosulfonates. Palladium-catalyzed aryl(alkyl)thiolation of unactivated arenes. Catalytic cycle for Pd-catalyzed aryl(alkyl)thiolation

Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach

• Dileep Kumar Singh and
• Rajesh Kumar

Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71

• gives N-sulfonylcarbazole 17 in 75–86% yields as shown in Scheme 7. This procedure provides the selectivities in a very short time and gives products in excellent yields. Zuo et al. [61] reported the Clauson–Kaas synthesis of N-substituted pyrroles 19 using scandium triflate as the catalyst in good to

• -substituted pyrroles 9. P2O5-catalyzed synthesis of N-substituted pyrroles 11. p-Chloropyridine hydrochloride-catalyzed synthesis of pyrroles 13. TfOH-catalyzed synthesis of N-sulfonylpyrroles 15, N-sulfonylindole 16, N-sulfonylcarbazole 17. Scandium triflate-catalyzed synthesis of N-substituted pyrroles 19

Pyridine C(sp²)–H bond functionalization under transition-metal and rare earth metal catalysis

• Haritha Sindhe,
• Malladi Mounika Reddy,
• Karthikeyan Rajkumar,
• Akshay Kamble,
• Amardeep Singh,
• Anand Kumar and
• Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

• pyridines by C–H addition to olefins under cationic half-sandwich rare-earth catalysis [50]. They carried out the reaction in the presence of dialkyl complexes of scandium (Sc) or yttrium (Y) such as (C5Me5)Ln(CH2C6H4NMe2-o)2 (Ln = Sc, Y) in combination with B(C6F5)3 as an activator. The method demonstrated

• a wide substrate scope of both pyridines and olefins including α-olefins, styrenes, and conjugated dienes. The yttrium complex was found to be superior as compared to the scandium complex for the alkylation reaction of bulkier 2-tert-butylpyridine with ethylene. In addition, the yttrium catalyst was

• pyridines with excellent substrate scope using a scandium catalyst (Scheme 16). A vast number of pyridines and allenes were studied as substrates to provide the C2-alkenylated pyridines in good to high yields. Based on the mechanistic experiments a possible catalytic cycle has been proposed (Scheme 16b

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• ) and excess of triene 53 was carried out using boron trifluoride diethyl etherate or zirconium(IV) tetrachloride to furnish product 54 in good yield (Scheme 15). The same group also explored the Diels–Alder reaction of menadione (10) with trienes 55, 57, and 59 (Scheme 16) [110]. The scandium(III

• equivalents of scandium(III) triflate, affording compound 58 in 70% yield. Finally, the optimized conditions were employed to react menadione (10) with the triene 59, using 5.0 equivalents of scandium(III) triflate, forming compound 60 in 55% yield. Additional studies were made, using protected trienes, and

A resorcin[4]arene hexameric capsule as a supramolecular catalyst in elimination and isomerization reactions

• Tommaso Lorenzetto,
• Fabrizio Fabris and
• Alessandro Scarso

Beilstein J. Org. Chem. 2022, 18, 337–349, doi:10.3762/bjoc.18.38

• ], p-toluenesulfonic acid [58][59] or with scandium tris(trifluoromethanesulfonate) [60]. These results clearly speak for the combined effect provided by the capsule consisting in sufficient Brønsted acidity and concomitant stabilization of the cationic intermediate within the electron-rich cavity

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

• catalysts for C–H activation processes deserves a better exploration. This review compilates the application of 3d metals as catalysts for C–H activation processes to obtain biologically active compounds or building blocks applied in the synthesis of molecules with known biological effects. Review Scandium

• -catalyzed C–H activation Scandium is the first metal of the 3d metals row. It is relatively cheap compared to heavier transition metals, and it is commonly used on catalytic procedures, such as catalyzed polymerization [31][32] and C–C coupling reactions [33][34]. It is also an increasing metal option to

• develop C–H activation methods, since it can be used as the metallic center of innovative and elaborated complexes [35][36]. Scandium-based catalysts have not been directly applied to the synthesis of known biologically active compounds via C–H activation reactions. Therefore, as challenging as it seems

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

Selective and reversible 1,3-dipolar cycloaddition of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes with 1,3-diphenylprop-2-en-1-ones under microwave irradiation

• Alexander P. Molchanov,
• Mariia M. Efremova,
• Mariya A. Kryukova and
• Mikhail A. Kuznetsov

Beilstein J. Org. Chem. 2020, 16, 2679–2686, doi:10.3762/bjoc.16.218

• earlier that the electronic properties of the substituted aryl group of diaziridines and chalcones showed a profound influence on the yields of a catalytic reaction (scandium triflate with a chiral ligand); when a phenyl or p-chloro/methylphenyl-substituted diaziridine was employed, the cycloaddition

Recent developments in enantioselective photocatalysis

• Callum Prentice,
• James Morrisson,
• Andrew D. Smith and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

• gadolinium catalyst and chiral ligand L2 (Scheme 43b) [108]. By altering the radical precursor to α-silyl amines 277 and using α,β-unsaturated amides 278, Yoon et al. found that the reactions could be stopped at the RCA step to give enantioenriched 1,4-addition products 279 using a scandium catalyst and

• scandium Lewis acid (ET = 1.43 eV), is significantly lower relative to the unbound substrate (ET = 2.34 eV). They propose that Lewis acid coordination permits discrimination between bound and unbound substrate as it allows for selective triplet sensitisation of the bound substrate by the excited state

Ferrocenyl-substituted tetrahydrothiophenes via formal [3 + 2]-cycloaddition reactions of ferrocenyl thioketones with donor–acceptor cyclopropanes

• Grzegorz Mlostoń,
• Mateusz Kowalczyk,
• André U. Augustin,
• Peter G. Jones and
• Daniel B. Werz

Beilstein J. Org. Chem. 2020, 16, 1288–1295, doi:10.3762/bjoc.16.109

• , which was widely applied in studies involving aromatic thioketones [3][4][5]. However, in contrast to 8a, the reaction of 8b with 5a was unsuccessful. This observation prompted us to replace AlCl3 by scandium triflate (Sc(OTf)3), which is also known to be an efficient catalyst in various reactions of D

• scandium triflate, Sc(OTf)3 as a catalyst, yielding highly functionalized tetrahydrothiophene derivatives of type 9. These formal [3 + 2]-cycloaddition reactions occurred via a nucleophilic attack of the sulfur atom on the activated cyclopropane ring at the most reactive benzylic position. The formation of

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

• enantioselective catalysis was reported by Evans and co-workers in 2005 [34]. The selected asymmetric transformation was the Friedel–Crafts 1,4-addition involving indole derivatives as nucleophiles, catalyzed by a scandium(III) triflate complex with chiral bis(oxazolinyl)pyridine ligands. As highlighted by Evans

SnCl₄-catalyzed solvent-free acetolysis of 2,7-anhydrosialic acid derivatives

• Kesatebrhan Haile Asressu and
• Cheng-Chung Wang

Beilstein J. Org. Chem. 2019, 15, 2990–2999, doi:10.3762/bjoc.15.295

• -anhydro bridges [29][30][31]. Accordingly, ᴅ-galactosamine and ᴅ‑allosamine derivatives were synthesized via scandium(III) triflate-catalyzed ring opening of 1,6-anhydroglucosamine derivatives [29][32]. However, there is a paucity of reports on the Lewis acid-catalyzed acetolysis of the 2,7-anhydro

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

• -dihydrotetrazolo[1,5-a]pyrimidine derivatives. Under similar conditions using 4,4,4-trifluoroacetoacetic ester 5-hydroxy-4,5,6,7-tetrahydrotetrazolo[1,5-a]pyrimidines are obtained. The analogous reaction with acetylacetone requires scandium(III) triflate as catalyst. The antioxidant activity of selected compounds

• product from the three-component process performed at room temperature. Its structure based on NMR spectral data corresponded to a two-component condensation of amine 1 and acetylacetone (10). The selective formation of the target compound 12 was achieved in the presence of scandium(III) triflate as a

• obtained with high selectivity by performing the reaction in the presence of scandium(III) triflate as a catalyst. 4,4,4-Trifluoromethylacetoacetic ester showed high reactivity in the current reaction forming the corresponding 5-hydroxy-5-trifluoromethyl-4,5,6,7-tetrahydrotetrazolo[1,5-a]pyrimidine as a

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

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

• associated with the reported methodologies. Amongst various reported TMs, the participation of copper as the catalyst has been used in the largest number of cases followed by the use of palladium, rhodium, and others. It has been further observed that lanthanum, scandium, and vanadium have been very seldomly

• used for functionalization/derivatization reactions compared to MCRs in the syntheses of IPs. The role of lanthanum/scandium/nickel/vanadium in synthetic chemistry The application of scandium complexes in organic chemistry has been very scarce due to their low availability and difficulties in

• separation. This problem was resolved by the introduction of scandium triflate (Sc(OTf)3) as a promising reusable Lewis acid in Diels–Alder reactions by Kobayashi [78]. However, in recent years scandium(III) trifluoromethanesulfonate (Sc(OTf)3) has emerged as an efficient, mild, commercially available

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

• also been performed by using scandium catalyst (Sc(OTf)3, 2.5 mol %) and starting from ester 29. Under these conditions, not only benzyl or alkyl, but also a wide range or ortho-, meta- and para-arylamines 2 can be used at room temperature to make 3-oxoisoindolinone-1-carbonitriles 53a in very good

β-Hydroxy sulfides and their syntheses

• Mokgethwa B. Marakalala,
• Edwin M. Mmutlane and
• Henok H. Kinfe

Beilstein J. Org. Chem. 2018, 14, 1668–1692, doi:10.3762/bjoc.14.143

• notable; this was the first enantioselective thiolysis of a meso-epoxide in pure water as a solvent. Since this report, several epoxide thiolysis reactions in water have been reported and are part of several reviews [45][46]. Schneider and co-workers reported the same scandium–bipyridine complex as

Chiral phase-transfer catalysis in the asymmetric α-heterofunctionalization of prochiral nucleophiles

• Johannes Schörgenhumer,
• Maximilian Tiffner and
• Mario Waser

Beilstein J. Org. Chem. 2017, 13, 1753–1769, doi:10.3762/bjoc.13.170

• investigated by this strategy [56][57][81][82][83]. In 2006 already, Inanaga and co-workers reported the use of chiral scandium-containing organophosphates G1 for the asymmetric α-fluorination of ketoesters 1 (Scheme 4) [81]. No clear mechanistic proposal was given in this interesting contribution and it

• turned out that scandium clearly outperforms other rare earth cations hereby, which makes it thus difficult to say if this is really a classical phase-transfer-catalysed reaction or rather a Lewis acid catalysed transformation controlled by a chiral counter anion (it is well known that chiral counter

Solvent-free, visible-light photocatalytic alcohol oxidations applying an organic photocatalyst

• Martin Obst and
• Burkhard König

Beilstein J. Org. Chem. 2016, 12, 2358–2363, doi:10.3762/bjoc.12.229

• ][10][11][12]. Some derivatives were also immobilized on silica gel and applied in the oxidation of benzyl alcohols [13]. Furthermore, it was shown that the oxidation power of RFTA can be increased by coordination to scandium triflate [14]. Recently, the E/Z-isomerization of olefins with riboflavin as

Solvent-free synthesis of novel para-menthane-3,8-diol ester derivatives from citronellal using a polymer-supported scandium triflate catalyst

• Lubabalo Mafu,
• Ben Zeelie and
• Paul Watts

Beilstein J. Org. Chem. 2016, 12, 2046–2054, doi:10.3762/bjoc.12.193

• environmentally friendly method for the synthesis of para-menthane-3,8-diol from natural citronellal oil in 96% yield, under solvent free aqueous conditions. The acylation of para-menthane-3,8-diol with various acid anhydrides over polymer-supported scandium triflate (PS-Sc(OTf)3) catalyst was subsequently

• the presence of amines such as pyridine, triethyl amine or 4-(dimethylamino)pyridine [7] homogeneous Lewis acid catalysts (AlCl3, BF3, TaCl5) [10] or inorganic acids are also used [11]. Recent publications have reported scandium triflate (Sc(OTf)3) to be an effective catalyst in the acylation of

• variety of applications. The synthesis method involves the acylation of 3 with various acid anhydrides. The synthesis method also employs a polymer-supported scandium triflate as a water resistant and environmentally friendly acid catalyst. Results and Discussion Synthesis para-menthane-3,8-diol from

Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

• Lucie Brulíková,
• Aidan Harrison,
• Marvin J. Miller and
• Jan Hlaváč

Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184

• and trapping of an intermediate acylnitroso dienophile in the presence of transition metals (Scheme 36), e.g., [67][136][137][138][139][140][141]. b) The second approach relies on the activation of a moderately reactive arylnitroso dienophile by scandium [142] or copper [103][104] metal ions, which

Tandem processes promoted by a hydrogen shift in 6-arylfulvenes bearing acetalic units at ortho position: a combined experimental and computational study

• Mateo Alajarin,
• Marta Marin-Luna,
• Pilar Sanchez-Andrada and
• Angel Vidal

Beilstein J. Org. Chem. 2016, 12, 260–270, doi:10.3762/bjoc.12.28

• activation of the benzylidenemalonate fragment by scandium(III) triflate as the catalyst (Scheme 1) [27]. Because fulvenes are widely used as the direct precursors of cyclopentadienyl anions following the addition of nucleophiles, including the hydride anion, to its exocyclic sp2 carbon atom [28][29], we

Synthesis of constrained analogues of tryptophan

• Elisabetta Rossi,
• Valentina Pirovano,
• Marco Negrato,
• Giorgio Abbiati and
• Monica Dell’Acqua

Beilstein J. Org. Chem. 2015, 11, 1997–2006, doi:10.3762/bjoc.11.216

• results are summarized in Table 1. The reaction was ineffective under thermal conditions (Table 1, entry 1). As a consequence we tested simple Lewis acids as potential promoters for the transformation. Magnesium perchlorate, scandium and copper triflate and boron trifluoride failed to give the desired

The unexpected influence of aryl substituents in N-aryl-3-oxobutanamides on the behavior of their multicomponent reactions with 5-amino-3-methylisoxazole and salicylaldehyde

• Volodymyr V. Tkachenko,
• Elena A. Muravyova,
• Sergey M. Desenko,
• Oleg V. Shishkin,
• Svetlana V. Shishkina,
• Dmytro O. Sysoiev,
• Thomas J. J. Müller and
• Valentin A. Chebanov

Beilstein J. Org. Chem. 2014, 10, 3019–3030, doi:10.3762/bjoc.10.320

• -dihydroisoxazolo[5,4-b]pyridine-5-carboxamide (5a) (Scheme 3) in the reaction mixture when the reaction was performed in n-butanol under conventional heating for 25 min using ytterbium or scandium triflate as the catalysts. Then, it was established that the three-component heterocyclization of aminoisoxazole 1