Electrochemical cyclization of alkynes to construct five-membered nitrogen-heterocyclic rings

• Lifen Peng,
• Ting Wang,
• Zhiwen Yuan,
• Bin Li,
• Zilong Tang,
• Xirong Liu,
• Hui Li,
• Guofang Jiang,
• Chunling Zeng,
• Henry N. C. Wong and
• Xiao-Shui Peng

Beilstein J. Org. Chem. 2025, 21, 2173–2201, doi:10.3762/bjoc.21.166

• -involved ureas, annulation of o-arylalkynylanilines, cyclization of 2-ethynylanilines, selenocyclization of diselenides with 2-ethynylanilines as well as C–H indolization of 2-alkynylanilines with 3-functionalized indoles. Isoindolones were synthesized successfully by electrochemical annulation of

• electrochemical selenocyclization of diselenides and 2-ethynylanilines (Scheme 5) [201]. After probing the reaction systematically, the optimal conditions were afforded as following: a mixture of 2-ethynylaniline 13 (0.2 mmol), diselenide 14 (0.13 mmol), n-Bu4NPF6 (0.04 mmol) and MeCN (5.0 mL), under electrolysis

• . Indole skeletons were obtained successfully through electrochemical coupling of urea derivatives, dehydrogenative annulation of alkynes with anilines, annulation of o-arylalkynylanilines, cyclization of 2-ethynylanilines, selenocyclization of diselenides with 2-ethynylanilines, and enantioselective

Halides as versatile anions in asymmetric anion-binding organocatalysis

• Lukas Schifferer,
• Martin Stinglhamer,
• Kirandeep Kaur and
• Olga García Macheño

Beilstein J. Org. Chem. 2021, 17, 2270–2286, doi:10.3762/bjoc.17.145

• complex or active nucleophiles. In 2014, Jacobsen et al. developed a highly enantioselective selenocyclization reaction of olefins 26, using the chiral squaramide 28 as a dual hydrogen bond donor (Scheme 6) [16]. Although early-stage enantio-enrichment during the introduction of selenium is hard to

• ) vinylboronic acids. Enantioselective selenocyclization catalyzed by squaramide 28. Desymmetrization of meso-aziridines catalyzed by bifunctional thiourea catalyst 31. Anion-binding-catalyzed desymmetrization of a) meso-aziridines catalyzed by chiral triazolium catalyst 34 by Ooi et al., and b) oxetans

Mechanism, kinetics and selectivity of selenocyclization of 5-alkenylhydantoins: an experimental and computational study

• Biljana M. Šmit,
• Radoslav Z. Pavlović,
• Dejan A. Milenković and
• Zoran S. Marković

Beilstein J. Org. Chem. 2015, 11, 1865–1875, doi:10.3762/bjoc.11.200

• and are consistent with our experimental results. The preferred pathway for formation of 5-exo products is confirmed. Keywords: density functional theory; fused bicyclic hydantoins; intermediate; reaction mechanism; regioselectivity; selenocyclization; Introduction Hydantoins, a class of

• selenocyclization of 5-alkenylhydantoins leading to fused bicyclic products [24]. To our best knowledge, no previous theoretical work has reported on this reaction. In this paper, density functional theory (DFT) [25][26][27][28] is utilized to understand the mechanism and selectivity of this key step in the

• work has provided the first theoretical study of the selenocyclization of 5-alkenylhydantoins. By 1H NMR monitoring of the reaction we proposed a five-step mechanism which involves the intermediate formed by the addition of selenium reagent on starting 5-alkenylhydantoin. The Markovnikov-type product