Silver-Catalyzed Tandem Synthesis of Naphthyridines and Thienopyridines via Three-Component Reaction

详细信息    查看全文

• 作者：Akhilesh K. Verma ; Siva K. Reddy Kotla ; Deepak Choudhary ; Monika Patel ; Rakesh K. Tiwari
• 刊名：The Journal of Organic Chemistry
• 出版年：2013
• 出版时间：May 3, 2013
• 年：2013
• 卷：78
• 期：9
• 页码：4386-4401
• 全文大小：705K
• 年卷期：v.78,no.9(May 3, 2013)
• ISSN：1520-6904

文摘

An efficient approach for the silver-catalyzed regioselective tandem synthesis of highly functionalized 1,2-dihydrobenzo[1,6]naphthyridines 6a鈥?b>z and 7a鈥?b>e by the reaction of ortho-alkynylaldehydes 3a鈥?b>n with amines 4a鈥?b>d and ketones 5a鈥?b>c/active methylene compounds 5d鈥?b>g, under mild reaction conditions, is described. The scope of the developed chemistry was successfully extended for the direct synthesis of 1,2-dihydrobenzo[4,5]thieno[2,3-c]pyridines 8a鈥?b>e, which is known as the sulfur analogue of 尾-carbolines. Naphthyridines 6a鈥?b>z and thienopyridines 8a鈥?b>e were obtained via dual activation concept using l-proline as organocatalyst; however, naphthyridines 7a鈥?b>e were synthesized without using organocatalyst. The reaction shows selective N鈥揅 bond formation on the more electrophilic alkynyl carbon, resulting in the regioselective 6-endo-dig-cyclized products. Reactivity behavior of electron-deficient and electron-rich ortho-alkynylaldehydes in the synthesis of naphthyridines and thienopyridine by three-component reaction is supported by the control experiment.