Conversion of 2-iodobiaryls into 2,2′-diiodobiaryls via oxidation-iodination sequences : a versatile route to ladder-type heterofluorenes

• Main Authors: Wu, Bin, Yoshikai, Naohiko
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2015
• Subjects: DRNTU::Science::Chemistry::Organic chemistry::Heterocyclic compounds
• Online Access: https://hdl.handle.net/10356/105682; http://hdl.handle.net/10220/26055; http://dx.doi.org/10.1002/anie.201503134
• Institution: Nanyang Technological University

Even though 2,2′-diiodo- and 2,2′-dibromobiaryls represent accomplished precursors for heterofluorenes and other extended π-conjugated systems, their preparation still remains nontrivial when structural diversity of the biaryl backbone is required. Herein, we report a convenient method for the preparation of various 2,2′-diiodobiaryls from 2-iodobiaryls via cyclic diaryliodonium intermediates. An iodinative ring-opening of the diaryliodonium salts, mediated by a copper/diamine catalyst system, is able to afford the corresponding 2,2′-diiodobiaryls under mild conditions. The versatility of this two-step approach is demonstrated by the preparation of hitherto unexplored tetraiodoteraryls and their conversion into ladder-type π-conjugated systems.