<i>N</i>,<i>N</i>-Dichloro-2-nitrobenzenesulfonamide as the Electrophilic Nitrogen Source for Direct Diamination of Enones
作者:Wei Pei、Han-Xun Wei、Dianjun Chen、Allan D. Headley、Guigen Li
DOI:10.1021/jo030193j
日期:2003.10.1
formations of 3-trichloromethyl and dichloromethyl imidazoline products (16 examples). The 2-Ns-protection group of the resulting diamine products can be easily cleaved under mild Fukuyama's conditions. A new mechanism hypothesis of [2+3] cyclization and N-chlorination has been proposed to explain the product structures, particularly their regio- and stereochemistry.
The combination of 2-NsNH2/NCS and MeCN as the nitrogen sources for the regio- and stereoselective formation of imidazolines from α,β-unsaturated ketones
作者:Cody Timmons、Dianjun Chen、C. Elizabeth Barney、Sameer Kirtane、Guigen Li
DOI:10.1016/j.tet.2004.10.022
日期:2004.12
A new nitrogen source combination was found for the regio- and stereoselective diamination of α,β-unsaturated ketones. This combination employs the readily available and inexpensive combination of NCS and 2-NsNH2 as the electrophilic nitrogen source, and acetonitrile as the nucleophilic nitrogen source, respectively. The reaction is easily performed by mixing olefin, 2-NsNH2, NCS and 4 Å molecular