Chiral Tetrafluorobenzobarrelene Ligands for the Rhodium-Catalyzed Asymmetric Cycloisomerization of Oxygen- and Nitrogen-Bridged 1,6-Enynes
作者:Takahiro Nishimura、Takahiro Kawamoto、Makoto Nagaosa、Hana Kumamoto、Tamio Hayashi
DOI:10.1002/anie.200906792
日期:2010.2.22
The long and winding Rhoad: The asymmetric cycloisomerization of nitrogen‐ and oxygen‐bridged 1,6‐enynes proceeded in the presence of a cationic rhodium complex that was coordinated by PPh3 and a chiral diene ligand to afford high yields of chiral 3‐aza‐ and 3‐oxabicyclo[4.1.0]heptenes and high enantioselectivities. TS=4‐toluenesulfonyl, Tf=trifluoromethanesulfonyl.
Rhoad蜿蜒曲折:在存在阳离子铑络合物(由PPh 3和手性二烯配体配位)的存在下,氮和氧桥联的1,6-烯炔的不对称环异构化进行,从而获得了高收率的手性3-氮杂和3-氧杂双环[4.1.0]庚烯和高对映选择性。TS = 4-甲苯磺酰基,Tf =三氟甲磺酰基。