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Rhodium‐Catalyzed Highly Diastereo‐ and Enantioselective Synthesis of a Configurationally Stable S‐Shaped Double Helicene‐Like Molecule
Author(s) -
Kinoshita Suzuka,
Yamano Ryota,
Shibata Yu,
Tanaka Yusuke,
Hanada Kyoichi,
Matsumoto Takashi,
Miyamoto Kazunori,
Muranaka Atsuya,
Uchiyama Masanobu,
Tanaka Ken
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202001794
Subject(s) - helicene , enantiopure drug , chirality (physics) , chemistry , molecule , racemization , enantioselective synthesis , stereochemistry , intramolecular force , trimer , crystallography , catalysis , organic chemistry , physics , chiral symmetry breaking , dimer , quantum mechanics , quark , nambu–jona lasinio model
Abstract An S‐shaped double helicene‐like molecule (>99 % ee ), possessing stable helical chirality, has been synthesized by the rhodium(I)/difluorphos complex‐catalyzed highly diastereo‐ and enantioselective intramolecular double [2+2+2] cycloaddition of a 2‐naphthol‐ and benzene‐linked hexayne. The collision between two terminal naphthalene rings destabilizes the helical chirality of the S‐shaped double helicene‐like molecule, but the introduction of two additional fused benzene rings significantly increases the configurational stability. Thus, no epimerization and racemization were observed even at 100 °C. The enantiopure S‐shaped double helicene‐like molecule forms a trimer through the multiple C−H⋅⋅⋅π and C−H⋅⋅⋅O interactions in the solid‐state. The trimers stack to form columnar packing structures, in which neighboring stacks have opposite dipole directions. The accumulation of helical structures in the same direction in the S‐shaped double helicene‐like molecule enhanced the chiroptical properties.