Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• of the Boc-protecting group with the Teoc group then gave phenol 136. Compound 136 was then subjected to a highly diastereoselective oxidative phenolic coupling giving fused tetracyclic architecture 137. Follow-up acid-mediated intramolecular aza-Michael addition and subsequent alkene reduction

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• . An o-phenolic coupling between two units of tyrosine furnishes the intermediate Int-1, which by deamination, selective reduction of one of the carboxylate groups, macrolactonization, and subsequent structural modifications would lead to the aforementioned combretastatins D (Scheme 1). The second

The biomimetic synthesis of balsaminone A and ellagic acid via oxidative dimerization

• Sharna-kay Daley and
• Nadale Downer-Riley

Beilstein J. Org. Chem. 2020, 16, 2026–2031, doi:10.3762/bjoc.16.169

• with shikimic acid, feature the dimerization of monomeric phenolic precursors by a laccase enzyme, a single-electron enzyme complex within macro-organisms which facilitates oxidative dimerization through phenolic coupling [19]. In the case of balsaminone A (4), lawsone (6) is methylated to ether 7

Biochemical and structural characterisation of the second oxidative crosslinking step during the biosynthesis of the glycopeptide antibiotic A47934

• Veronika Ulrich,
• Clara Brieke and
• Max J. Cryle

Beilstein J. Org. Chem. 2016, 12, 2849–2864, doi:10.3762/bjoc.12.284

• homologues can display significantly different catalytic propensities despite their overall similarities. Keywords: crystal structure; cytochrome P450; glycopeptide antibiotic; peptide; phenolic coupling; Introduction The glycopeptide antibiotics (GPAs) are a series of highly modified heptapeptide natural

• previously been shown to form a tight interaction with StaH, the P450 responsible for the first (C-O-D) phenolic coupling reaction in A47934 biosynthesis [12]. Prior to analysis by SEC, a mixture of StaF and a 3-fold excess of Xsta as well as each individual protein was incubated in appropriate buffer (50 mM

• was then analysed with the flow rate set to 1 mL/min and detection of the absorption at λ = 280 and 415 nm. Individual analysis of StaF and Xsta served as controls. P450 activity assay An in vitro phenolic coupling assay was performed in order to determine the StaF activity. As substrates the