Catalytic enantioselective iodocyclization of gamma-hydroxy-cis-alkenes.
Enantioselective iodocyclization of gamma-hydroxy-cis-alkenes has been achieved using I2 in the presence of an unprecedented catalyst system generated from (R,R)-t-Bu-salen-Co(II) complex and NCS to produce 2-monosubstituted tetrahydrofurans up to 90% ee. While NCS turned out to be the essential additive, neither (R,R)-salen-Co(II) nor (R,R)-salen-Co(III) by itself is likely to be the active species responsible for the asymmetric intramolecular iodoetherification.
Kang
Sung Ho
SH
Center for Molecular Design and Synthesis, Department of Chemistry, School of Molecular Science (BK21), Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
Lee
Sung Bae
SB
Park
Chul Min
CM