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Redox‐Neutral Rhodium‐Catalyzed CH Functionalization of Arylamine N ‐Oxides with Diazo Compounds: Primary C(sp 3 )H/C(sp 2 )H Activation and Oxygen‐Atom Transfer
Author(s) -
Zhou Bing,
Chen Zhaoqiang,
Yang Yaxi,
Ai Wen,
Tang Huanyu,
Wu Yunxiang,
Zhu Weiliang,
Li Yuanchao
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201505302
Subject(s) - chemistry , diazo , rhodium , catalysis , iminium , aniline , regioselectivity , medicinal chemistry , annulation , catalytic cycle , redox , coupling reaction , reactive intermediate , photochemistry , organic chemistry
An unprecedented rhodium(III)‐catalyzed regioselective redox‐neutral annulation reaction of 1‐naphthylamine N‐oxides with diazo compounds was developed to afford various biologically important 1 H ‐benzo[g]indolines. This coupling reaction proceeds under mild reaction conditions and does not require external oxidants. The only by‐products are dinitrogen and water. More significantly, this reaction represents the first example of dual functiaonalization of unactivated a primary C(sp 3 )H bond and C(sp 2 )H bond with diazocarbonyl compounds. DFT calculations revealed that an intermediate iminium is most likely involved in the catalytic cycle. Moreover, a rhodium(III)‐catalyzed coupling of readily available tertiary aniline N‐oxides with α‐diazomalonates was also developed under external oxidant‐free conditions to access various aminomandelic acid derivatives by an O‐atom‐transfer reaction.