Enantioselective Aziridination of Unactivated Terminal Alkenes Using a Planar Chiral Rh(III) Indenyl Catalyst
Patrick Gross, Hoyoung Im, David Laws III, Bohyun Park, Mu-Hyun Baik*, Simon B. Blakey*
*Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, ROK; Emory University, Atlanta, Georgia 30322, United States,
Email: mbaik2805
kaist.ac.kr, sblakeyemory.edu
P. Gross, H. Im, D. Laws III, B. Park, M.-H. Baik, S. B. Blakey, J. Am. Chem. Soc., 2024, 146, 1447-1454.
DOI: 10.1021/jacs.3c10637
see article for more reactions
Abstract
A planar chiral rhodium indenyl catalyst facilitates the enantioselective aziridination of unactivated alkenes with a remarkable degree of functional group tolerance and excellent chemoselectivity. Computational studies unveil a stepwise aziridination mechanism in which alkene migratory insertion plays a central role.
see article for more examples
proposed mechanism
General Aziridination Procedure
An oven-dried 4 dram reaction vial, with Teflon tape wrapped threads, and equipped with an oven dried stir bar was brought into the glovebox. The nitrene source (0.13 mmol, 1.3 equiv.), CsOAc (0.01mmol, 0.1 equiv.), AgSbF6 (0.30 mmol, 0.3 equiv.), and 2 (2.5 mol%) were added to the reaction vial. The vial was sealed with a Teflon septum screw cap and brought out of the box to complete the reaction. Under an N2 atmosphere, HFIP (1.0 mL, 0.1M) was added directly to the reaction vial followed by the olefin (0.10 mmol, 1.0 equiv.) using a micro syringe. For alkenes with unknown densities, a stock solution in HFIP (1.0 mL, 0.1M) was prepared in advance. The reaction was left to stir at room temperature under a N2 balloon for 24 hours. After 24 hours the crude reaction was filtered through a Celite pipette plug using DCM to flush. The solvent was removed under reduced pressure and the crude material purified via preparative TLC using the indicated eluent to yield the corresponding aziridine product.
Key Words
ID: J48-Y2024
