3‐Mono‐Substituted BINOL Phosphoric Acids as Effective Organocatalysts in Direct Enantioselective Friedel–Crafts‐Type Alkylation of N‐Unprotected α‐Ketiminoester
most widely used chiral Brønsted acid organocatalysts, their structures are mostly limited to 3,3′‐disubstituted ones and simple 3‐mono‐substituted ones without any polar functionalities on the 3‐substituent have not been used in highly enantioselective reactions. This work reports such 3‐mono‐substituted analogues as effective organocatalysts in direct highly enantioselectiveFriedel–Crafts‐type alkylation
Triflic Acid-Catalyzed Highly Stereoselective Friedel−Crafts Aminoalkylation of Indoles and Pyrroles
作者:Mohammed Abid、Liliana Teixeira、Béla Török
DOI:10.1021/ol703095d
日期:2008.3.1
simple and efficient synthesis to both enantiomers of highly enantiomerically enriched alpha-trifluoromethyl-alpha-(heteroaryl)-glycine derivatives via highly stereoselective aminoalkylation of indoles and pyrroles is described. The triflic acid-catalyzed reaction of enantiomeric 3,3,3-trifluoro-pyruvate-alpha-methylbenzyl imines with indoles and pyrroles and the subsequent Pd-catalyzed hydrogenolysis of