N-H insertion reactions of primary ureas: the synthesis of highly substituted imidazolones and imidazoles from diazocarbonyls.
Primary ureas have been used as substrates in rhodium-catalyzed N-H insertion reactions with an array of diazocarbonyls. The insertion reaction is efficient and gives excellent selectivity and yields. The products from the insertion reaction with diazoketones cyclize readily in the presence of acid to yield the corresponding imidazolones that can be further derivatized by N-alkylation with alkyl, allyl, and benzyl halides. Alternatively, the imidazolones were treated with phosphorus oxybromide to form the corresponding 2-bromoimidazoles that were further functionalized using a Suzuki coupling reaction.
Lee
Sang-Hyeup
SH
Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Yoshida
Kazuhiro
K
Matsushita
Hana
H
Clapham
Bruce
B
Koch
Guido
G
Zimmermann
Jürg
J
Janda
Kim D
KD
D001391:Azo Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D007093:Imidazoles / Q000138:chemical synthesis*; D015394:Molecular Structure; D012238:Rhodium / Q000737:chemistry; D014508:Urea / Q000031:analogs & derivatives* / Q000138:chemical synthesis*
D001391:Azo Compounds; D007093:Imidazoles; C117197:imidazolone; D014508:Urea; D012238:Rhodium