Journal of Organic Chemistry p. 644 - 653 (1989)
Update date:2022-09-26
Topics: Synthesis NMR spectroscopy Catalyst Indoles Silyl group Pyrrolo<1,2-a>indoles Dipolar cycloaddition N-<(Trimethylsilyl)methyl>-substituted
Padwa, Albert
Fryxell, Glen E.
Gasdaska, John R.
Venkatramanan, M. K.
Wong, George S. K.
The 1,3-dipolar cyloaddition of a number of N-<(trimethylsilyl)methyl>-substituted indoles with several dipolarophiles has been investigated.The reaction requires the use of an equivalent amount of silver fluoride and provides a direct and efficient synthesis of the pyrrolo<1,2-a>indole ring system.The structures of the cycloadducts were established by high-field NMR spectroscopy as well as by several X-ray crystal structures.The cycloaddition reactions show all the characteristics of a concerted reaction, including complete stereospecificity and regioselectivity.The results are consistent with a mechanism that involves the intermediacy of an azomethine ylide.Formation of the dipole is rationalized by assuming that silver ion behaves as a very specific Lewis acid that attacks the indole ring to give a silver bonded carbonium ion.This is followed by a rapid desilylation reaction to give the azomethine ylide.After the cycloaddition step, the resulting silver-bonded intermediate undergoes consecutive loss of silver and a hydrogen to give the observed product.Attempts to extend the cycloaddition methodology to N-<(trimethysilyl)methyl>-substituted enamines and pyrroles are also described.
View MoreContact:+86-0512-62857507
Address:Boji Science Park, No1688C,Taishan road, Suzhou ,China
Yibin Hope Pharmaceutical Co., Ltd.
Contact:+86-831-5109851 86-831-5109836
Address:Luolong Industrial Zone,Nanxi, Yibin City, Sichuan, China. | Email: wishmarketing@gmail.com | Website: http://www.hopepharma.cc/
Lianyungang Yunbo Chemical Co.,Ltd.
Contact:518-81066110
Address:B907,Dongsheng"Mingdu Square,21-2 East Chaoyang Road,Xinpu,(sale department)
Taizhou Elitechemie MediPharma Technology Co.,Ltd.
Contact:+86-523-86810021
Address:Building G14,NO.1 Avenue,China Medical City, Taizhou, Jiangsu,China
Tianjin Realet Chemical Technology Co.,Ltd.
website:http://www.realetchem.com
Contact:+86-022-58788819
Address:shuanggang industrial park
Doi:10.1080/00397910802663410
(2009)Doi:10.1021/ja057751r
(2006)Doi:10.1246/cl.2007.946
(2007)Doi:10.1016/j.bmc.2016.12.033
(2017)Doi:10.1016/j.ejmech.2009.12.072
(2010)Doi:10.1002/anie.200702349
(2007)