Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemistry , University of Science and Technology of China , Hefei 230026 , China.
Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072 , China.
Org Lett. 2018 Apr 20;20(8):2485-2489. doi: 10.1021/acs.orglett.8b00870. Epub 2018 Apr 3.
A palladium(II)-catalyzed asymmetric 1,2-diamination of 1,3-dienes with readily available dialkylureas was established by using a chiral pyridine-oxazoline ligand. The diamination reaction exclusively occurs at the terminal C-C double bond of the 1,3-dienes to give 4-vinylimidazolidin-2-ones in high yields and with excellent levels of enantioselectivity (up to 99% yield, 97% ee). The reaction could feasibly be applied for gram-scale synthesis with a 1:1 ratio of the diene and the urea.
钯（II）催化的 1,3-二烯与易得的二烷基脲的不对称 1,2-二氨基化反应通过使用手性吡啶-噁唑啉配体得以建立。二氨基化反应仅在 1,3-二烯的末端 C-C 双键处发生，以高收率和优异的对映选择性（高达 99%收率，97%ee）得到 4-乙烯基咪唑烷-2-酮。该反应可以通过在二烯和脲的 1:1 比例下进行克级合成来实现。
