available catalyst consisting of iron dichloride in combination with 1,10‐phenanthroline catalyzes the ring‐closing C−H amination of N‐benzoyloxyurea to form imidazolidin‐2‐ones in high yields. The C−H amination reaction is very general and applicable to benzylic, allylic, propargylic, and completely non‐activated aliphatic C(sp3)−H bonds, and it also works for C(sp2)−H bonds. The surprisingly simple method
An enantioselective intramolecular C(sp3)–H amination of N-benzoyloxyurea by using a chiral-at-metal rutheniumcatalyst is reported, providing chiral 2-imidazolidinones in yields of up to 99% and with up to 99% ee. Catalyst loadings down to 0.05 mol % are feasible. Control experiments support a stepwise nitrene insertion mechanism through hydrogen atom transfer of a ruthenium nitrenoid intermediate
<scp>Iron‐Catalyzed</scp>
Intramolecular C—H Amidation of
<scp>
<i>N</i>
‐Benzoyloxyureas
</scp>
作者:Dayou Zhong、Lin‐Yang Wu、Xing‐Zhen Wang、Wen‐Bo Liu
DOI:10.1002/cjoc.202100005
日期:2021.4
A redox‐neutral Fe‐catalyzed intramolecular C—H amidation of N‐benzoyloxyureas is described. This methodology employs a simple iron complex in situ generated from Fe(OTf)2 and bipyridine as the catalyst and N‐benzoyloxyureas as the nitrene precursors without using exogenous oxidants. An array of cyclic ureas were synthesized via aliphatic C(sp3)—H amidation in excellent yields. In addition, this catalytic