Direct Cyanation of Heteroaromatic Compounds Mediated by Hypervalent Iodine(III) Reagents: In Situ Generation of PhI(III)−CN Species and Their Cyano Transfer
作者:Toshifumi Dohi、Koji Morimoto、Naoko Takenaga、Akihiro Goto、Akinobu Maruyama、Yorito Kiyono、Hirofumi Tohma、Yasuyuki Kita
DOI:10.1021/jo061820i
日期:2007.1.1
in our laboratory provided insights into the real active iodine(III) species during the reaction; the reaction is induced by an active hypervalent iodine(III) species having a cyano ligand in situ generated by ligand exchange reaction at the iodine(III) center between trifluoroacetoxy group in PIFA and TMSCN, and effective cyanide introduction into heteroaromatic compounds is achieved by means of the
Palladium-Catalyzed Annulation of Aryl Heterocycles with Strained Alkenes
作者:David G. Hulcoop、Mark Lautens
DOI:10.1021/ol070475w
日期:2007.4.1
An annulation reaction proceeding by the intermolecular addition of an arylpalladium(II) halide across a strained alkene, followed by an intramolecular C-H functionalization of a pendant heterocycle is described. A variety of polycyclic heterocycles have been prepared from readily accessible haloaryl heterocycles by annulation with a range of strained alkene partners.
SAKAI KAZUO; SUZUKI MAMORU; NUNAMI KEN-ICHI; YONEDA NAOTO; ONODA YUICHI; +, CHEM. AND PHARM. BULL., 1980, 28, NO 8, 2384-2393
Novel and Direct Oxidative Cyanation Reactions of Heteroaromatic Compounds Mediated by A Hypervalent Iodine(III) Reagent
作者:Toshifumi Dohi、Koji Morimoto、Yorito Kiyono、Hirofumi Tohma、Yasuyuki Kita
DOI:10.1021/ol0476826
日期:2005.2.1
The hypervalent iodine(III) reagent phenyliodine bis(trifluoroacetate) (PIFA) mediates the selective cyanation reactions of a wide range of electron-rich heteroaromatic compounds such as pyrroles, thiophenes, and indoles under mild conditions. These reactions proceed via a cation radical intermediate, and the key for the successful transformation presumably depends on the oxidation-reduction potential
Various dimethyl 3-substituted pyrrole-2, 4-dicarboxylates (3) were synthesized by the reaction of methyl isocyanoacetate (2) with methyl α-isocyanoacrylates (5) in the presence of base. This type of reaction was also applicable to the preparation of 3-substituted pyrrole-2, 4-dicarboxamides (10) by employing appropriate amide compounds (8) or (9) and (12) as reactants. Hydrolysis followed by decarboxylation of the pyrrole diester compounds (3) gave 3-substituted pyrroles (14) in good yields. A series of these compounds (14) showed antiinflammatory activities against carrageenan-induced rat paw edema. Among the compounds tested, 3-(2-chlorophenyl) pyrrole (14d) was found to be more potent than mefenamic acid.