On-Resin Conjugation of Diene鈥揚olyamides and Maleimides via Diels鈥揂lder Cycloaddition

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• 作者：Omar Brun ; Xavier Elduque ; Enrique Pedroso ; Anna Grandas
• 刊名：Journal of Organic Chemistry
• 出版年：2015
• 出版时间：June 19, 2015
• 年：2015
• 卷：80
• 期：12
• 页码：6093-6101
• 全文大小：466K
• ISSN：1520-6904

文摘

The reaction between maleimides and resin-linked diene鈥損olyamides allows the latter to be used in the preparation of conjugates. Conjugation takes place by reacting the insoluble, hydrophobic diene component either with water-soluble dienophiles or with dienophiles requiring mixtures of water and organic solvents. Experimental conditions can be adjusted to furnish the target conjugate in good yield with no need of adding large excesses of soluble reagent. In case protected maleimides are used, maleimide deprotection and Diels鈥揂lder cycloaddition can be simultaneously carried out to render conjugates with different linking positions. On-resin conjugation is followed by an acidic treatment that removes the polyamide protecting groups with no harm to the cycloadduct, in contrast with the unreacted diene that is indeed degraded under these conditions. Cycloadducts incorporating suitable functional groups can undergo subsequent additional conjugation reactions in solution to furnish double conjugates.