Introducing C2 asymmetry in chromans—a brief story

Abstract

Trost group’s notable attempts in the 1990s synthesizing several natural products like vitamin E and its analogs, clusifoliol, rhododaurichromanic acid A, siccanin, calanolide A and B etc. through palladium-catalyzed asymmetric...

Transition Metal‐Catalyzed Enantioselective Synthesis of Chiral Five‐ and Six‐Membered Benzo O‐heterocycles

“…Phomoxanthone A (X) also performs anticancer, antitubercular, and antibacterial activities, which possesses a dimeric tetrahydroxanthone structure.. [11] Therefore, chemists have devoted to developing novel and efficient synthetic transformations to access chiral benzo Oheterocycles. Some elegant reviews have been documented in this flourishing area, including catalytic enantioselective pathways lead to 2,3-dihydrobenzofurans, [12] benzofuranones, [13] chromans, [14] chromenes, [15] phthalides, [16] phthalans, [17] isochromans, [18] flavonoids [19] and flavanones. [20] Among them, transition metal (TM) catalyzed reactions [21] are considered to be one of the most efficient and attractive strategies to give chiral benzo O-heterocycles because of its convenience on the construction of complex molecular architectures from readily available starting materials under mild reaction conditions.…”