Synthesis of heterocycles based on azomethine ylides from α-amino acids (or amines) and carbonyl compounds

• Ekaterina V. Berezhnaya,
• Alexander I. Ponyaev,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2026, 22, 705–741, doi:10.3762/bjoc.22.55

• compounds; catalysis; (3 + 2) cycloaddition; decarboxylation; dipolarophiles; iminoesters; polycyclic compounds; spirocyclic compounds; stereoselectivity; Introduction The 1,3-dipolar cycloaddition is one of the most popular pericyclic reactions in organic synthesis, in which a dipole molecule interacts

• strategy is that the synthesis is often carried out under mild conditions without the use of a catalyst, and despite this, the resulting cycloadducts exhibit pronounced regio- and stereoselectivity [9][10][11]. In the second case, the generation of azomethine ylides from iminoesters is often realized using

• development of this method is also presented. Review Imine derivatives as precursors of azomethine ylides Azomethine ylides based on iminoesters In 2002, Zhang and co-workers described a highly enantioselective Ag(I)-catalyzed (3 + 2) cycloaddition of azomethine ylides from α-(arylimino)esters using AgOAc as

C2 to C6 biobased carbonyl platforms for fine chemistry

• Jingjing Jiang,
• Muhammad Noman Haider Tariq,
• Florence Popowycz,
• Yanlong Gu and
• Yves Queneau

Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165

Synthesis of 1-indolyl-3,5,8-substituted γ-carbolines: one-pot solvent-free protocol and biological evaluation

• Premansh Dudhe,
• Mena Asha Krishnan,
• Kratika Yadav,
• Diptendu Roy,
• Krishnan Venkatasubbaiah,
• Biswarup Pathak and
• Venkatesh Chelvam

Beilstein J. Org. Chem. 2021, 17, 1453–1463, doi:10.3762/bjoc.17.101

• salts has been discovered. Results and Discussion Optimization of reaction conditions and chemical synthesis The base-catalyzed imination of aromatic aldehydes is a valuable method in organic synthesis to synthesize a variety of heterocyclic building blocks [29]. Among all the reported iminoesters

Synthesis of (Z)-3-[amino(phenyl)methylidene]-1,3-dihydro-2H-indol-2-ones using an Eschenmoser coupling reaction

• Lukáš Marek,
• Lukáš Kolman,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2021, 17, 527–539, doi:10.3762/bjoc.17.47

• from iminoesters [11] (see Table 2, entries 9, 13, 14, and 21–23). However, the inspection of Table 2 does not show any clear dependence between the electronic properties of the substituent R1 or R2 and the isolated yield. In most cases the yields are higher than 80%, but it seems that the presence of

Novel biphenyl-substituted 1,2,4-oxadiazole ferroelectric liquid crystals: synthesis and characterization

• Mahabaleshwara Subrao,
• Dakshina Murthy Potukuchi,
• Girish Sharada Ramachandra,
• Poornima Bhagavath,
• Sangeetha G. Bhat and
• Srinivasulu Maddasani

Beilstein J. Org. Chem. 2015, 11, 233–241, doi:10.3762/bjoc.11.26

• -oxides to azomethines, nitriles and iminoesters. In the present study, we synthesized 1,2,4-oxadiazoles through amidoxime intermediates with substitutions at C-3 and C-5 positions. A moiety with a chiral center is attached to the phenyl ring (at C-5 position) of oxadiazole in the molecular structure. The

Chiral gold(I) vs chiral silver complexes as catalysts for the enantioselective synthesis of the second generation GSK-hepatitis C virus inhibitor

• María Martín-Rodríguez,
• Carmen Nájera,
• José M. Sansano,
• Abel de Cózar and
• Fernando P. Cossío

Beilstein J. Org. Chem. 2011, 7, 988–996, doi:10.3762/bjoc.7.111

• demonstrated by our group, establishing a wider scope and sensibly higher enantioselectivities for the reactions performed in the presence of chiral phosphoramidite/silver(I) complexes [24]. Concerning enantioselective gold(I)-catalyzed 1,3-DC, the classical cycloaddition starting from iminoesters 6 has not

• been so extensively explored. Reports of chiral transformations involving azlactones [32][33] and iminoesters 6 [34], which employed chiral diphosphines and gold(I) salts, have been published showing very good endo-diastereoselectivities and moderate to excellent enantioselectivities. However, the use

• were freshly distilled under an argon atmosphere. Aldehydes were also distilled prior to use for the elaboration of the iminoesters. Melting points were determined with a Reichert Thermovar hot plate apparatus and are uncorrected. Only the structurally most important peaks of the IR spectra (recorded