A cascade synthesis of 2-aminothiochromones from 2-fluorophenyl ketone and thiocarbonyldiimidazole

• Kai Zhang,
• Haofan Shao,
• Kangjun Liao,
• Ying Xu,
• Shimei Du,
• Yanfang Zhao,
• Gang Li,
• Wenzhen Xu,
• Haihong Huang and
• Peng Li

Beilstein J. Org. Chem. 2026, 22, 1151–1159, doi:10.3762/bjoc.22.92

• (TCDI) acted as a key precursor in the construction of a sulfur-containing scaffold from 2-fluorophenyl ketone. Subsequent conjugated addition–elimination resulted in the corresponding 2-aminothiochromones under mild conditions. This simple protocol tolerates a broad range of functional groups and

• provides concise access to various 2-aminothiochromones in good to excellent yields (up to 94%). Keywords: cascade synthesis; TCDI; thiochromone; Introduction Sulfur-containing motifs are particularly important owing to their widespread applications and diverse biological activities [1]. As isosteric

• , which serve as key intermediates in benzothiazinone synthesis, using thiocarbonyldiimidazole (TCDI) as a sulfur source [30]. Inspired by these works and driven by our continued interest in thiochromone synthesis, we wondered whether it would be possible to combine thiochromone construction with amino

Generation of alkyl and acyl radicals by visible-light photoredox catalysis: direct activation of C–O bonds in organic transformations

• Mithu Roy,
• Bitan Sardar,
• Itu Mallick and
• Dipankar Srimani

Beilstein J. Org. Chem. 2024, 20, 1348–1375, doi:10.3762/bjoc.20.119

• thiocarbonyl derivatives were prepared by reaction of thiocarbonyldiimidazole (TCDI, 15) with alcohols in the presence of a catalytic amount of DMAP (0.4 equiv). TCDI is a very popular substrate for such reaction types and was first introduced by Barton and McCombie (Scheme 6) [20]. In this process, the

Synthesis of ergostane-type brassinosteroids with modifications in ring A

• Vladimir N. Zhabinskii,
• Darya A. Osiyuk,
• Yuri V. Ermolovich,
• Natalia M. Chaschina,
• Tatsiana S. Dalidovich,
• Miroslav Strnad and
• Vladimir A. Khripach

Beilstein J. Org. Chem. 2017, 13, 2326–2331, doi:10.3762/bjoc.13.229

• of epicastasterone (1), epibrassinolide (2) and A-ring units 3–12 of BS biosynthetic precursors/metabolites. (a) Ac2O, Py, DMAP, 60 °C; (b) K2CO3, MeOH, 20 °C (97% over 2 steps); (c) TCDI, DMAP, THF, 65 °C (76%); (d) (EtO)3P, 150 °C (94%); (e) KOH, MeOH, 65 °C (89%). (a) MsCl, Py, 20 °C (95%); (b) Zn

Enduracididine, a rare amino acid component of peptide antibiotics: Natural products and synthesis

• Darcy J. Atkinson,
• Briar J. Naysmith,
• Daniel P. Furkert and
• Margaret A. Brimble

Beilstein J. Org. Chem. 2016, 12, 2325–2342, doi:10.3762/bjoc.12.226

• with isothiourea 33 followed by mesyl chloride afforded cyclic guanidine 72 in 70% yield. Silyl deprotection, Swern oxidation and Still–Gennari olefination afforded Z-alkene 73. Diastereoselective dihydroxylation of 73 followed by treatment with 1,1'-thiocarbonyldiimidazole (TCDI) and sodium azide