Synthesis of an aza[5]helicene-incorporated macrocyclic heteroarene via oxidation of an o-phenylene-pyrrole-thiophene icosamer

• Yusuke Matsuo,
• Aoi Nakagawa,
• Shu Seki and
• Takayuki Tanaka

Beilstein J. Org. Chem. 2025, 21, 1561–1567, doi:10.3762/bjoc.21.119

• in detail. Keywords: cyclophane; fluorescence; heterohelicene; intramolecular oxidative coupling; Introduction Conjugated macrocyclic polyarenes have attracted significant attention due to their stimuli-responsive optoelectronic properties, dynamic structural changes, and host–guest interactions [1

• largest macrocycle ever synthesized is a dodecameric hybrid array of 1,2-phenylene, 2,5-thienylene, and 2,5-pyrrolylene units [22][23]. The intramolecular oxidative coupling of these arrays afforded heterohelicene-incorporated macrocycles D and E, depending on the relative arrangements of the pyrrole and

• and nanobelt. (b) Cyclo[4]helicenylene and cyclo(oxa[5]helicenylene-biphenylene). (c) Intramolecular oxidative coupling of cyclic o-phenylene-pyrrole-thiophene dodecamers. X-ray crystal structure of 4. Thermal ellipsoids are scaled to 50% probability level. Solvent molecules and hydrogen atoms except

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• [4,5]thieno[3,2-c][1,2]dithiin (39) was prepared by intramolecular oxidative coupling of a dithiolate generated in situ from dithioacetate 38, and subsequent exposition to daylight of a solution of 39 triggered ring contraction with concomitant elimination of sulfur to yield target benzothienothiophene

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• asymmetric conjugate addition. The magnesium enolates 56 then participated in a copper(II)-mediated intramolecular oxidative coupling to afford benzofused spirocyclic cycloalkanones 57 (Scheme 14) [45]. Our team became interested in domino reactions of metal enolates generated by Cu-catalyzed asymmetric

Synthesis of 2-oxindoles via 'transition-metal-free' intramolecular dehydrogenative coupling (IDC) of sp² C–H and sp³ C–H bonds

• Nivesh Kumar,
• Santanu Ghosh,
• Subhajit Bhunia and
• Alakesh Bisai

Beilstein J. Org. Chem. 2016, 12, 1153–1169, doi:10.3762/bjoc.12.111

• to the phenyl ring. The α-carbonylalkyl radicals were formed by Cu(II)-mediated oxidation of the respective enolate precursors. In 2010, Yu and co-workers have reported the synthesis of 3-acetyloxindoles via Ag2O-mediated intramolecular oxidative coupling [45]. For the past few years, our group is

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• oxidative coupling sequence (Scheme 48). Similarly, the tricyclic N-heterocyclic core in natural (+)-asperazine and idiospermuline was also efficiently synthesized in 71% overall yield. The oxindole was reduced to the lactol by NaBH4, which was then subjected to a camphorsulfonic acid (CSA)-promoted

• ), which have been widely used as versatile intermediates for synthesizing biologically important indole containing compounds. The method was also successfully applied to the construction of the tetracyclic core that exists in natural azonazine through a reductive cyclization/MnO2-mediated intramolecular

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142