[217459-11-5] · C22H28FeN2 · (MW 376.90)
(chiral catalyst for the O-to-C rearrangement of O-acylated enolates, the kinetic resolution of primary amines, and the dynamic kinetic resolution/ring opening of azlactones)
Physical Data: mp 165-172 °C.
Solubility: soluble in t-amyl alcohol, chlorinated, aromatic, and ethereal solvents.
Form Supplied in: burgundy crystals.
Handling, Storage, and Precautions: can be handled in air; best if stored under nitrogen.
This chiral derivative of 4-(pyrrolidino)pyridine (PPY) serves as an enantio-selective catalyst for the rearrangement of O-acylated enolates to their C-acylated isomers, a process first described by Steglich using PPY and DMAP.1 With the chiral PPY derivative, a new quaternary stereocenter is produced in excellent yield and very good enantiomeric excess (
This chiral PPY derivative also serves as an effective catalyst for the kinetic resolution of primary amines.5 O-Acylated azlactones are the acyl-ating agents of choice -with more conventional reagents such as acid chlorides and anhydrides, the uncatalyzed background reaction is significant. Selectivity factors (selectivity factor = (rate of fast-reacting enantiomer)/(rate of slow-reacting enantiomer)) ranging from 11 to 27 are obtained for aryl/alkyl-substituted primary amines (
A closely related catalyst 2 (NMe2 in place of the pyrrolidino group) effects the dynamic kinetic resolution/ring opening of azlactones with moderate enantioselection (
Massachusetts Institute of Technology, Cambridge, MA, USA