Synthesis of functionalized 2-salicyloylfurans, furo[3,2-b]chromen-9-ones and 2-benzoyl-8H-thieno[2,3-b]indoles by one-pot cyclizations of 3-halochromones with β-ketoamides and 1,3-dihydroindole-2-thiones.
Functionalized 2-salicyloylfurans and 2-benzoyl-8H-thieno[2,3-b]indoles were prepared under mild conditions by reaction of 3-halochromones with β-ketoamides and 1,3-dihydroindole-2-thiones, correspondently. The subsequent oxidative cyclization of the products resulted in formation of the corresponding furo[3,2-b]chromen-9-ones. These molecules could also be directly prepared from 3-halochromones using a one-pot protocol. The cyclization reactions reported herein are mechanistically surprising as they proceed via the oxygen and not via the (more nucleophilic) nitrogen atom of the β-ketoamide.
Institut für Chemie, Universität Rostock, Albert Einstein Str. 3a, 18059 Rostock, Germany. iva108@googlemail.com peter.langer@uni-rostock.de.
Iryna
I
Savych
Tim
T
Gläsel
Alexander
A
Villinger
Vyacheslav Ya
VY
Sosnovskikh
Viktor O
VO
Iaroshenko
Peter
P
Langer
D000577:Amides / Q000737:chemistry*; D001578:Benzopyrans / Q000138:chemical synthesis*; D002384:Catalysis; D003500:Cyclization; D005663:Furans / Q000138:chemical synthesis*; D007211:Indoles / Q000138:chemical synthesis*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D020156:Salicylic Acid / Q000737:chemistry; D013237:Stereoisomerism; D013871:Thiones / Q000138:chemical synthesis*
D000577:Amides; D001578:Benzopyrans; D005663:Furans; D007211:Indoles; D013871:Thiones; C520957:beta-ketoamide; D020156:Salicylic Acid