Morita F,
Kishida Y,
Sato Y,
Sugiyama H,
Abekura M,
Nogami J,
Toriumi N,
Nagashima Y,
Kinoshita T,
Fukuhara G,
Uchiyama M,
Uekusa H,
Tanaka K.
*
Tokyo Institute of Technology, Japan
Design and Enantioselective Synthesis of 3D π-Extended Carbohelicenes for Circularly Polarized Luminescence.
Nat. Synth. 2024;
3: 774-786
Key words
circularly polarized luminescence - carbohelicenes - [2+2+2] cycloaddition - Scholl reaction
Significance
π-Extended helicenes of intrinsic chirality are promising circularly polarized luminescence (CPL) emitters, but their preparations and resolution are challenging. Here, enantioselective syntheses of 3D π-extended carbo[11] and carbo[13] helicenes with bright CPL emissions and large asymmetry coefficients are achieved.
Comment
The synthesis features enantioselective triple [2+2+2] cycloaddition, followed by multi-fold annulation through Scholl reaction, which further reduces the helicene diameter. Crystallization of the enantioenriched helicene products readily yields nearly pure enantiomers.
