Bismuth Nitrate-Catalyzed Versatile Michael Reactions
作者:Neeta Srivastava、Bimal K. Banik
DOI:10.1021/jo026550s
日期:2003.3.1
Bismuth nitrate-catalyzed versatile Michael reaction was developed to reduce the complications that characterize the current standard Michael reaction and used for facile preparation of organiccompounds of widely different structures. For example, several substituted amines, imidazoles, thio compounds, indoles, and carbamates were prepared at room temperature by following this method. In contrast
Iodine-catalyzed highly efficient Michael reaction of indoles under solvent-free condition
作者:Bimal K. Banik、Miguel Fernandez、Clarissa Alvarez
DOI:10.1016/j.tetlet.2005.02.044
日期:2005.4
Michael reaction of indoles with unsaturated ketones has been accomplished in the presence of catalytic amount of iodine under solvent-free condition. (c) 2005 Published by Elsevier Ltd.
Bismuth Nitrate-Catalyzed Michael Reactions of Indoles in Water
作者:Bimal K. Banik、Isabella Garcia、Frances R. Morales
DOI:10.3987/com-06-10957
日期:——
Catalytic Conjugate Additions of Nitrogen-, Phosphorus-, and Carbon-Containing Nucleophiles by Amphoteric Vanadyl Triflate
作者:Yow-Dzer Lin、Jun-Qi Kao、Chien-Tien Chen
DOI:10.1021/ol702302y
日期:2007.12.1
A series of carbamates, amides, N-tosyl amides, (hetero)arenes, and hydrogen phosphines/phosphites has been examined as nucleophiles for (hetero)Michael-type additions to enones and enamides catalyzed by amphoteric vanadyl triflate under mild and neutral conditions. The newly developed C-N, C-P, and C-C bond-formation protocols were carried out smoothly in good to high yields without intervention of any 1,2-additions.
Regioselective N- and C2-electrophilic substitution of 3-substituted indoles
The reaction of 3-substituted indoles with 2-cyclohexenone under Lewis acid mediated conditions with Bi(NO3)(3)-5H(2)O has been investigated. We have demonstrated that electrophilic substitution of 3-substituted indoles with 2-cyclohexenone will readily occur at the nitrogen. Furthermore, the extent of regioselectivity is dependent on reaction solvent and the C3-substituent. Excellent conversion is obtained with good to excellent isolated yields of N- and C2-adducts. In general, more polar, aprotic solvents (CH3CN) give greater N-selectivity whereas with polar protic solvents (CH3OH) an increase in the C2-adduct is observed. (c) 2005 Elsevier Ltd. All rights reserved.