Palladium-Catalyzed Enantioselective C-3 Allylation of 3-Substituted-1H-Indoles Using Trialkylboranes
摘要:
We have developed a new enantioselective C-3 allylation of 3-substituted indoles using allyl alcohol and trialkylboranes. Asymmetric syntheses of 3,3-disubstituted indolines and indolenines in enantiomeric excesses up to 90% have been achieved using the bulky borane 9-BBN-C6H13 as the promoter of the reaction. The dependence of the selectivity on the nature of the borane suggests that the boron reagent has a role beyond promoting ionization of the allyl alcohol. A protocol for oxidation of indolenines to oxindoles has also been developed and led to a formal synthesis of (-)-phenserine.
We evaluated the influence of solvent on the alumina‐promoted C3‐alkylation of indoles with α,β‐unsaturatedketones. We found that lipophilic solvents were generally superior to hydrophilic ones with hexanes offering the 3‐alkyl indole products in high yields. Thus, we demonstrate an inexpensive and procedurally simple new process that pairs acidic alumina with hexanes to achieve this important Michael
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
Compounds of formula (I)
and pharmaceutically acceptable salts thereof are agonists at the beta-2 adrenoceptor. They are useful as feed additives for livestock animals.
式(I)的化合物及其药用可接受的盐是β-2肾上腺素受体的激动剂。它们可用作家畜动物的饲料添加剂。
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