521270-76-8Relevant articles and documents
Chemoselective double annulation of two different isocyanides: Rapid access to trifluoromethylated indole-fused heterocycles
Gao, Yuelei,Hu, Zhongyan,Dong, Jinhuan,Liu, Jun,Xu, Xianxiu
, p. 5292 - 5295 (2017/11/06)
An unprecedented chemoselective double annulation of α-trifluoromethylated isocyanides with o-acylaryl isocyanides has been developed. This new reaction provides a rapid, efficient, and complete atom-economic strategy for the synthesis of trifluoromethylated oxadiazino[3,2-α]indoles in a single operation from readily available starting materials. Isocyanide insertion into C=O double bonds is disclosed for the first time as indicated by the results of 18O-labeling experiment. A mechanism for this domino reaction is proposed involving chemoselective heterodimerization of two different isocyanides, followed by indole-2,3-epoxide formation and rearrangement.
Isocyanide cyclization reactions: 4-methylene-4H-benzo[d][1,3]oxazine, 3-benzyl-4-methylene-3,4-dihydroquinazolines and 3-(4-benzyl)-3H-quinazolin-4- ones - Experiment and theory
Neue, Benedikt,Reiermann, Ralph,Froehlich, Roland,Wibbeling, Birgit,Bergander, Klaus,Wuerthwein, Ernst-Ulrich
, p. 4944 - 4952 (2013/08/23)
2-Isocyanoacetophenone (3a) was found to be an easily accessible starting material for the unexpected formation of various heterocyclic systems. Thus, a hitherto unknown rather unstable 4-methylene-4H-benzoxazine derivative 4, which could be characterized by NMR spectroscopy, was formed in situ by the reaction of 3a in the presence of weak acids. In the presence of benzylamines, a new class of 3,4-dihydroquinazoline derivatives 6 and their oxidation products, quinazolin-4-ones 9, were obtained. The starting materials and products were completely characterized by spectroscopic and X-ray analysis. The scope and limitations of these cyclization reactions were investigated under various reaction conditions. High-level quantum chemical calculations were carried out to elucidate the mechanisms leading to scaffolds 4 and 6. The calculations suggest that the formation of 4 and 6 involves the generation of an unusual six-membered N-heterocyclic carbene or its C-protonated form as a reaction intermediate, followed by tautomerisation. This mechanism might also be applicable to other isocyanide cyclization reactions. Copyright
A convenient synthesis of quinolines by reactions of o-isocyano-β- methoxystyrenes with nucleophiles
Kobayashi, Kazuhiro,Yoneda, Keiichi,Miyamoto, Kazuna,Morikawa, Osamu,Konishi, Hisatoshi
, p. 11639 - 11645 (2007/10/03)
2,4-Disubstituted quinolines have been synthesized by reactions of o-isocyano-β-methoxystyrenes, which can be easily prepared from commercially available o-aminophenyl ketones in three steps, with alkyl(or aryl)lithiums in generally good yields. Subsequently, o-isocyano-β- methoxystyrenes have also proved to react efficiently with lithium dialkylamides to afford the corresponding 4-substituted N,N-dialkylquinolin-2-amines in satisfactory yields. Graphical Abstract.
