Efficient one-step synthesis of chiral bidentate oxazoline-alcohol ligands via a cyclic imidate ester rearrangement

Bidentate cycloimidate palladium complexes with aliphatic and aromatic anagostic bonds

“…27,28 This argument is supported by the results of Noel et al: primary oxazoline alcohols were obtained by reaction of sterically less crowded cyclic imidates with aminols. 29 Our spectroscopic proof of this finding is not only based on the chemical shift of the CH 2 group in the proton NMR as described previously, 28 but also on two-dimensional 1 H, 13 C-HMBC spectra: 3c for instance exhibits only a single cross signal for the imine carbon (d = 159.4 ppm) and the aliphatic proton at the chiral center (d = 4.37 ppm). A correlation with the neighboring methylene group (d = 3.67 ppm) is clearly missing, which on the other hand should be additionally registered for structures of type 2.…”

Ferrocene-derived P,N ligands: synthesis and application in enantioselective catalysis

“…It was also shown that the results depended strongly on the choice of the appropriate N,O-bis(trimethylsilyl)acetamide (BSA)-activator. A comparison with several related nitrogen donor ligands, like 43 and 44, revealed that the presence of the imidate nitrogen donor [61,62] is required for both the high enantioselectivities as the broad substrate scope.…”

Chiral imidate–ferrocenylphosphanes: synthesis and application as P,N-ligands in iridium(i)-catalyzed hydrogenation of unfunctionalized and poorly functionalized olefins

“…Previously, imidate precursors were synthesized via a mild procedure starting from 2-methylbenzonitriles 4. 12 A Wohl-Ziegler reaction with 3 equiv. NBS affords selectively the dibrominated product 5.…”