Access to Enantiomerically Enriched cis-2,3-Disubstituted Azetidines via Diastereoselective Hydrozirconation
摘要:
An asymmetric variant of the hydrozirconation reaction has been established starting from Boc-protected chiral allylic amines. The resulting diastereoselectively formed N-functionalized organozirconiums can be considered as promising chirons. In this case, they have been transformed into enantiomerically enriched cis-2,3-disubstituted azetidines through a iodination/cyclization sequence.
Direct, Intermolecular, Enantioselective, Iridium-Catalyzed Allylation of Carbamates to Form Carbamate-Protected, Branched Allylic Amines
作者:Daniel J. Weix、Dean Marković、Mitsuhiro Ueda、John F. Hartwig
DOI:10.1021/ol901151u
日期:2009.7.2
The direct reaction between carbamates and achiral allylic carbonates to form branched, conveniently protected primary allylicamines with high regioselectivity and enantioselectivity is reported. This process occurs without base or with 0.5 equiv K3PO4 in the presence of a metalacyclic iridium catalyst containing a labile ethylene ligand. The reactions of aryl-, heteroaryl-, and alkyl-substituted