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

• bismuth(III) triflate. The use of tert-butyl hydroperoxide in the presence of bismuth(III) triflate for the methylation of 1,4-naphthoquinone (1) provided 10 in 43% yield, in already optimized conditions (Scheme 3). Demethylation of 2-methyl-1,4-dimethoxynaphthalene The oxidative demethylation of 1,4

• mol % bismuth(III) triflate catalyst and compound 73 was obtained in 75% yield (Scheme 23). Carbonyl condensation Another possible derivatization involves transformations at the carbonyl groups in menadione that can be achieved through the addition of nucleophiles to the carbonyl group at position C-4

• resulted in an increase of menadione (10) conversion (40%) and also in the reaction selectivity (95%) (Scheme 22C). Another approach involving menadione acetylation was reported by Yadav and co-workers, who described a methodology for the synthesis of acetylated quinone derivatives catalyzed by bismuth(III

Synthesis of acylglycerol derivatives by mechanochemistry

• Karen J. Ardila-Fierro,
• Andrij Pich,
• Marc Spehr,
• José G. Hernández and
• Carsten Bolm

Beilstein J. Org. Chem. 2019, 15, 811–817, doi:10.3762/bjoc.15.78

• catalysts such as iron(III) chloride or bismuth(III) triflate was reported. However, the implementation of these protocols in the ball mill only led to trace amounts (less than 5% yield) of the protected monoacylglycerol 4a. Finally, one of the well-established Jacobsen catalysts for the epoxide ring

Efficient oxidation of oleanolic acid derivatives using magnesium bis(monoperoxyphthalate) hexahydrate (MMPP): A convenient 2-step procedure towards 12-oxo-28-carboxylic acid derivatives

• Jorge A. R. Salvador,
• Vânia M. Moreira,
• Rui M. A. Pinto,
• Ana S. Leal and
• José A. Paixão

Beilstein J. Org. Chem. 2012, 8, 164–169, doi:10.3762/bjoc.8.17

• : bismuth(III) triflate; δ-hydroxy-γ-lactones; MMPP; oleanolic acid; triterpenoid; Findings The molecular diversity that arises from research into natural products represents a valuable tool for driving drug discovery and development [1][2]. In this context, pentacyclic triterpenoids are currently regarded

• -lactones can be efficiently converted into the corresponding 12-oxo-28-carboxylic acid derivatives by bismuth(III) triflate catalysis [18]. This new approach not only avoids an inconvenient multistep synthesis by means of a protection/deprotection strategy [19][20] but also results in chemical modification

• “ecofriendly” reaction conditions, which avoid the use of large amounts of toxic and corrosive materials [47][48][49][50][51]. Bearing in mind the solubility properties of MMPP and that both the oxidative 28,13β-lactonization and the bismuth(III) triflate-catalyzed direct opening of δ-hydroxy-γ-lactones are