- Chemoselective double annulation of two different isocyanides: Rapid access to trifluoromethylated indole-fused heterocycles
-
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.
- Gao, Yuelei,Hu, Zhongyan,Dong, Jinhuan,Liu, Jun,Xu, Xianxiu
-
supporting information
p. 5292 - 5295
(2017/11/06)
-
- Synthesis of 4-alkylidene-4H-3,1-benzoxazine derivatives by acid-catalyzed cyclization of 2-isocyanophenyl ketones in the presence of a vinyl ether
-
2-(1-Alkoxyalkyl)-4-alkylidene-4H-3,1-benzoxazines are conveniently prepared by the reaction of 1-(2-isocyanophenyl) ethanones or 1-(2-isocyanophenyl)propan-1-ones with a vinyl ether, such as 2-methoxypropene or ethyl vinyl ether, in the presence of a catalytic amount of (±)-camphor-10-sulfonic acid. Georg Thieme Verlag Stuttgart.
- Kobayashi, Kazuhiro,Okamura, Yuta,Konishi, Hisatoshi
-
experimental part
p. 1494 - 1498
(2009/12/06)
-
- Horseradish peroxidase-mediated aerobic and anaerobic oxidations of 3-alkylindoles
-
Little is known about the HRP-mediated oxidations of 3-alkylindoles. Whereas 3-methylindole and 3-ethylindole were found to be turned over smoothly by HRP, reactions of tryptophol and N-acetyltryptamine were inefficient. Oxidations of the former two indoles by HRP under aerobic conditions led to the corresponding ring-opened o-acylformanilides and oxindoles, whereas anaerobic oxidations resulted in oxidative dimerization. The major products of anaerobic oxidation of 3-methylindole were shown to be two hydrated dimers, while anhydrodimers were obtained in the 3-ethyl case. The proposed mechanism involves HRP-mediated one-electron oxidation to give an indole radical that either dimerizes (anaerobic conditions) or reacts with O2 (aerobic conditions). Measured kinetics of indole oxidation by HRP compounds I and II mirrored their relative reactivities under turnover conditions. The observed comparable binding affinities for all four indole substrates investigated suggest that the low reactivity of tryptophol and N-acetyltryptamine reflect binding to HRP in an orientation that is disadvantageous to electron transfer oxidation of the indole ring.
- Ling, Ke-Qing,Sayre, Lawrence M.
-
p. 3543 - 3551
(2007/10/03)
-
- MECHANISM OF Co(SALEN)-CATALYZED OXYGENOLYSIS OF INDOLE RING AS A MODEL FOR THE TRYPTOPHAN-2,3-DIOXYGENASE REACTION
-
In the Co(Salen)-catalyzed oxygenolysis of 3-methylindole giving rise to o-formyl-aminoacetophenone, the actual active catalyst species has been found to be the Co(III)-(Salen) complex of an anion of the product.The catalysis involves activation of the substrate but not molecular oxygen.The activation of the substrate involves the rate determining proton transfer from the substrate to the product anion in the coordination sphere of the catalyst.
- Nishinaga, A.,Ohara, H.,Tomita, H.,Matsuura, T.
-
p. 213 - 216
(2007/10/02)
-