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Rhodium‐Catalyzed Enantioselective Synthesis, Structures, and Properties of Single and Double Azahelicene‐Like Molecules
Author(s) -
Hanada Kyoichi,
Nogami Juntaro,
Miyamoto Kazunori,
Hayase Norihiko,
Nagashima Yuki,
Tanaka Yusuke,
Muranaka Atsuya,
Uchiyama Masanobu,
Tanaka Ken
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202005479
Subject(s) - helicene , enantioselective synthesis , racemization , rhodium , chemistry , molecule , enantiopure drug , stereochemistry , intramolecular force , epimer , cationic polymerization , catalysis , organic chemistry
The enantioselective synthesis of aza[6] and [7]helicene‐like molecules have been achieved by the cationic rhodium(I)/axially chiral biaryl bisphosphine complex‐catalyzed intramolecular [2+2+2] cycloaddition of cyanodiynes. This protocol was successfully applied to the diastereo‐ and enantioselective synthesis of an S‐shaped double aza[6]helicene‐like molecule with a high ee value of 89 %. Although no epimerization and racemization were observed in the double carbo[6]helicene‐like molecule at 80 °C, epimerization and racemization of the double aza[6]helicene‐like molecule proceeded at 80 °C. This double aza[6]helicene‐like molecule showed good fluorescent quantum yields and chiroptical responses under both neutral and acidic conditions.