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Rhodium‐Catalyzed N ‐ tert ‐Butoxycarbonyl (Boc) Amination by Directed CH Bond Activation
Author(s) -
Wippich Julian,
Truchan Nadina,
Bach Thorsten
Publication year - 2016
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201600410
Subject(s) - amination , chemistry , reactivity (psychology) , thiophene , catalysis , rhodium , medicinal chemistry , reductive amination , azide , organic chemistry , combinatorial chemistry , medicine , alternative medicine , pathology
N ‐ tert ‐Butoxycarbonyl azide (BocN 3 ) was shown to be an efficient and economic source for the directed introduction of N ‐Boc protected amino groups into the thiophene and benzene nucleus. Yields for the amination of 2‐pyridin‐2‐ylthiophenes (10 examples) were 52–88%. For the amination of the respective benzenes (10 examples) yields between 54% and 99% were recorded with an improved reactivity observed for substrates that bear an electron‐withdrawing group. The reaction was applied to short total syntheses of the indoloquinoline alkaloids quindoline and cryptolepine. The facile removal of the Boc protecting group was the key to the success of the syntheses. The scope of the reaction was extended to a C( sp 3 )H bond amination and to the amination of 2‐phenyloxazoline. For the amination of 2‐pyridin‐2‐ylbenzene a kinetic deuterium isotope effect of 2.0 was determined.