N-h insertion reactions of Boc-amino acid amides: solution- and solid-phase synthesis of pyrazinones and pyrazines.
A series of alpha-diazo-beta-ketoesters were reacted with Boc amino acid amides in the presence of rhodium octanoate catalyst. The resulting N-H insertion products were treated with acid, providing the 1,4-azine intermediates, which were oxidized by air to form the corresponding pyrazine-6-one products. The pyrazine-6-ones were further derivatized by N-alkylation or by conversion to the arylpyrazines using sequential bromination and Suzuki coupling reactions. [reaction: see text]
Matsushita
Hana
H
Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Lee
Sang-Hyeup
SH
Yoshida
Kazuhiro
K
Clapham
Bruce
B
Koch
Guido
G
Zimmermann
Jürg
J
Janda
Kim D
KD
D000596:Amino Acids / Q000737:chemistry; D004952:Esters / Q000737:chemistry; D005563:Formic Acid Esters; D011719:Pyrazines / Q000138:chemical synthesis*; D012238:Rhodium
D000596:Amino Acids; D004952:Esters; D005563:Formic Acid Esters; D011719:Pyrazines; C000345:t-butyloxycarbonyl group; D012238:Rhodium