Rearrangement of o-(pivaloylaminomethyl)benzaldehydes: an experimental and computational study

• Csilla Hargitai,
• Györgyi Koványi-Lax,
• Tamás Nagy,
• Péter Ábrányi-Balogh,
• András Dancsó,
• Gábor Tóth,
• Judit Halász,
• Angéla Pandur,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2020, 16, 1636–1648, doi:10.3762/bjoc.16.136

• ; ring-chain tautomerism; Introduction In a preliminary publication [1] we disclosed that methylenedioxy-substituted o-(pivaloylaminomethyl)benzaldehyde (1a), when kept in dichloromethane (DCM) in the presence of a catalytic amount (0.13 equiv) of trifluoroacetic acid (TFA) for 72 h at room temperature

Synthesis and fluorescent properties of N(9)-alkylated 2-amino-6-triazolylpurines and 7-deazapurines

• Andrejs Šišuļins,
• Jonas Bucevičius,
• Yu-Ting Tseng,
• Irina Novosjolova,
• Kaspars Traskovskis,
• Ērika Bizdēna,
• Huan-Tsung Chang,
• Sigitas Tumkevičius and
• Māris Turks

Beilstein J. Org. Chem. 2019, 15, 474–489, doi:10.3762/bjoc.15.41

• –3.95 (m, γ) and the broadening of signals at 7.69 (s, a), 4.04 (t, b) and 3.84–3.74 (m, c). A similar type of the ring–chain tautomerism is expected to occur in 6-azido-2-amino-7-deazapurines (synthetic intermediates on the way 3→10/11), but it was not studied in detail due to their relatively low

Synthesis of functionalised β-keto amides by aminoacylation/domino fragmentation of β-enamino amides

• Pavel Yanev and
• Plamen Angelov

Beilstein J. Org. Chem. 2018, 14, 2602–2606, doi:10.3762/bjoc.14.238

• –chain tautomerism in compounds 11b,c,f,j (n = 2) and reduction to the corresponding β-hydroxy amides 12. Yields of compounds 3 and 5 (R1 = Ph, n = 0), obtained according to Scheme 1 and Scheme 2. Yields of compounds 4 and 11 (R2 = R3 = H), obtained according to Scheme 1 and Scheme 6. Supporting

• aqueous NaOAc. Proposed mechanism for the formation of side products 6. Proposed mechanism for the formation of the target β-keto amides 5. Reactivity of analogues 9, lacking the auxiliary amino group [34]. Domino fragmentation of compounds 4 (R2 = R3 = H) to N-protected ω-amino-β-keto amides 11. Ring

A computational study of base-catalyzed reactions of cyclic 1,2-diones: cyclobutane-1,2-dione

• Nargis Sultana and
• Walter M. F. Fabian

Beilstein J. Org. Chem. 2013, 9, 594–601, doi:10.3762/bjoc.9.64

• bicyclic intermediate Int4 was found (Figure 4). Furthermore, this intermediate did not react to product P3 but instead through a concerted ring opening and proton transfer to P3a. The anticipated product P3 of path C is a γ-oxocarboxylate. Such γ-oxocarboxylic acids or carboxylates are prone to ring–chain

• tautomerism [32][33]. Product P3a essentially is the ion-dipole complex between the ring tautomer of neutral γ-oxobutanoic acid with [OH(H2O)5]– , and hence, its formation is completely reasonable. The actual pathway C obtained by the calculations is indicated in Scheme 5. In fact, Int4 is barely stable if

Advances in synthetic approach to and antifungal activity of triazoles

• Kumari Shalini,
• Nitin Kumar,
• Sushma Drabu and
• Pramod Kumar Sharma

Beilstein J. Org. Chem. 2011, 7, 668–677, doi:10.3762/bjoc.7.79

• nitrogen atoms. However, flash vacuum pyrolysis at 500 °C leads to loss of molecular nitrogen (N2) to produce aziridine. Certain triazoles are relatively easy to cleave by ring–chain tautomerism. Synthesis of triazoles Substituted 1,2,3-triazoles can be produced by the azide–alkyne Huisgen cycloaddition in