An efficient procedure was developed to synthesize oxazoline as key intermediate in the total synthesis of (+)-lactacystin using palladium(0)-catalyzed intramolecular cyclization of isopentenyl benzamide via a π-allylpalladiumcomplex. A convenient and efficient method was developed for the synthesis of the optically pure α-amino-β-hydroxy acid.
AcOLeDMAP and BnOLeDMAP: Conformationally Restricted Nucleophilic Catalysts for Enantioselective Rearrangement of Indolyl Acetates and Carbonates
作者:Trisha A. Duffey、Scott A. Shaw、Edwin Vedejs
DOI:10.1021/ja805541u
日期:2009.1.14
The rate of indotyl O- to C-acetyl or carboxyl rearrangement is accelerated by the electron-withdrawing N-diphenylacetyl group (DPA) using the conformationally restricted chiral catalysts AcOLeDMAP (12b) and BnOLeDMAP (13b). Highly enantioselective conversion to quaternary C-acetylated and C-carboxylated oxindoles is observed, even for substrates containing branched substituents. The rearrangement of the carboxylate substrates 19 occurs with complementary enantiofacial selectivity using catalyst 13b compared to the acetyl migrations of 16 catalyzed by 12b. Access to N-unsubstituted oxindoles is demonstrated by DPA cleavage with Et2NH.
JPH08198837A
申请人:——
公开号:JPH08198837A
公开(公告)日:1996-08-06
Tandem Palladium-catalyzed Allene Arylation and Oxazoline Formation