Salen–scandium(III) complex-catalyzed asymmetric (3 + 2) annulation of aziridines and aldehydes

• Linqiang Wang and
• Jiaxi Xu

Beilstein J. Org. Chem. 2025, 21, 1087–1094, doi:10.3762/bjoc.21.86

• moieties of biologically active compounds. A salen–scandium triflate complex-catalyzed asymmetric (3 + 2) annulation of dialkyl 1-sulfonylaziridine-2,2-dicarboxylates and aldehydes generated optically active functionalized oxazolidine derivatives in moderate to good yields and good to excellent

• enantioselectivities and high diastereoselectivities. A reasonable reaction mechanism was proposed and rationalized the experimental results. Keywords: aldehyde; annulation; aziridine; oxazolidine; ring expansion; scandium triflate; Introduction Oxazolidine derivatives are an important class of nitrogen and oxygen

• method uses readily available salen as chiral ligand, which coordinates with scandium triflate to generate a salen–Sc complex acting as efficient catalyst. The catalytic asymmetric (3 + 2) annulation of dialkyl 3-aryl-1-sulfonylaziridine-2,2-dicarboxylates and aldehydes generated optically active

Organocatalytic kinetic resolution of 1,5-dicarbonyl compounds through a retro-Michael reaction

• James Guevara-Pulido,
• Fernando González-Pérez,
• José M. Andrés and
• Rafael Pedrosa

Beilstein J. Org. Chem. 2025, 21, 473–482, doi:10.3762/bjoc.21.34

• described in the literature (Scheme 5) [41][42]. Treatment of a 3:1 mixture of the anti/syn-diastereoisomers of compound 3 with 1,3-propane dithiol in the presence of a small amount of scandium triflate [43] afforded compound 18, which was used in the next step without further purification. Hydrogenolysis

• acetate mixtures as eluent. Experimental procedure for the chemical correlation of 3 with 19. In a Wheaton flask, 3 (53 mg, 0.16 mmol), 1,3-propane dithiol (21 mg, 0.19 mmol, 1.2 equiv), and scandium triflate (3 mg, 0.0064 mmol, 0.04 equiv) in CH2Cl2 were mixed, and the resulting mixture was stirred for

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

• aliphatic and aromatic aldehydes, both with electron-donating (ED) and electron-withdrawing (EW) substituents. It is worth mentioning that Gd triflate is much cheaper than scandium triflate, and that in this study the so called “gadolinium break” phenomenon [6], a discontinuity in the lanthanide properties

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

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

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

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

• 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

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

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