Chiral discrimination of small substituents in biaryl atropisomer construction: enantioselective synthesis of axially chiral 1-azafluorene via Ni-catalyzed [2+2+2] cycloaddition. - Peng, Jin-Huang; Zheng, Yu-Qing; Bai, Li-Gang; Liu, Wen-Bo (SCIENCE CHINA Chemistry, 2023)