＜正＞In recent years,xanthenes especially benzoxanthens have attracted attention of chemists due to their wide r...
Jianan Jin~1,Jianmin Zhang~(1,2*),Wenli Shang~1,Subo Shen~1,Cong Liu~1, Shizheng Zhu~(2*) 1 Department of Chemistry,School of Science,Shanghai University,No.99,Shangda Road, Shanghai 200444,China 2 Key Laboratory of Organofluorine Chemistry,Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences,354 Fenglin Lu,Shanghai 200032,China.
We have developed an efficient method to achieve N-gem-difluorocyclopropylation of N-heterocycles with the use of gem-difluorocyclopropyl tosylate as a building block under mild conditions. gemDifluorocyclopropyl tosylates could be easily prepared on a large scale and exhibit great stability.
Enantioselective synthesis of functionalized fluorinated dihydropyrano[2,3-c]pyrazoles has been achieved via a diaminocyclohexane-thiourea catalyzed cascade Michael addition and Thorpe-Ziegler type cyciization in high yields(up to 98%) with moderate to good enantioselectivity(up to 90% ee).
