0000000001318092
AUTHOR
Verena Sukowski
Enantioselective addition of Et2Zn to seven‐membered cyclic imines catalyzed by a (R)-VAPOL-Zn(II) complex
Various substituted dibenzo[b,f][1,4]oxazepines underwent an enantioselective alkylation with Et2Zn catalyzed by a (R)-VAPOL-Zn(II) complex. The corresponding chiral 11-ethyl-10,11-dihydrodibenzo[b,f][1,4]oxazepine derivatives were obtained with good yields and moderate enantioselectivities. This represents the first example of enantioselective addition of Et2Zn to cyclic aldimines.
Catalytic enantioselective aza-Reformatsky reaction with seven-membered cyclic imines dibenzo[b,f][1,4]oxazepines
A catalytic enantioselective aza-Reformatsky reaction is reported with cyclic dibenzo[b,f][1,4]oxazepines and ethyl iodoacetate leading to the synthesis of chiral ethyl 2-(10,11-dihydrodibenzo[b,f][1,4]oxazepin-11-yl)acetate derivatives with excellent yields and high enantioselectivities (up to 98% yield and 97 : 3 er) using a readily available diaryl prolinol L4 as the chiral ligand and Me2Zn as the zinc source under an air atmosphere. Furthermore, different transformations were carried out with the corresponding chiral β-amino esters, preserving in all cases the optical purity.
CCDC 1530500: Experimental Crystal Structure Determination
Related Article: Lode De Munck, Verena Sukowski, Carlos Vila, M. Carmen Muñoz, José R. Pedro|2017|Org.Chem.Front.|4|1624|doi:10.1039/C7QO00329C