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Synthesis of Fluorescent 4‐Azapyrenes by Palladium(II)‐Catalyzed Dual C−H Bond Activation and Annulation
Author(s) -
Hsiao HuanChang,
Annamalai Pratheepkumar,
Jayakumar Jayachandran,
Sun ShangYou,
Chuang ShihChing
Publication year - 2021
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.202001404
Subject(s) - chemistry , annulation , bathochromic shift , fluorescence , palladium , photochemistry , catalysis , superacid , cycloisomerization , benzofuran , medicinal chemistry , organic chemistry , physics , quantum mechanics
Unique dual‐emissive and deep‐blue/green fluorescent multi‐substituted 4‐azapyrenes with bathochromic shift emission, quantum yields up to 0.60 and long excited‐state lifetime were synthesized successfully by annulative π‐extension reactions. This synthesis constitutes a palladium‐catalyzed dehydrogenative annulation of N ‐acyl‐2‐aminobiaryls with in situ 1,3‐diynes as a key step, giving substituted phenanthrenes via a rollover C−H bond activation, followed by Bischler‐Napieralski cyclization. Further π‐extension by superacid‐mediated cyclization produced a blue fluorescent naphtho 4‐azapyrene.