The chiralBrønstedacid (1b or 1c) has been shown to initiate the Hosomi−Sakurai reaction of imines with excellent enantioselectivities. The combined Brønstedacid system has been developed to offer a new class of chiralBrønstedacidcatalysis. The present system proceeds through regeneration of the chiralBrønstedacid by proton transfer from additional Brønstedacid to silylated chiral Brønsted
Chiral Phosphoric Acid Catalyzed Peroxidation of Imines
作者:Wenhua Zheng、Lukasz Wojtas、Jon C. Antilla
DOI:10.1002/anie.201002972
日期:2010.9.3
Something to COO about: The title reaction provides direct access to α‐amino peroxides with high enantioselectivity (see scheme). The phosphoricacid catalyst is thought to activate both the nucleophile and electrophile through hydrogen‐bonding interactions.
Chiral Phosphoric Acid Catalyzed Addition of Dihydropyrans to <i>N</i>-Acyl Imines: Stereocontrolled Access to Enantioenriched Spirocyclic Oxazoletetrahydropyrans with Three Contiguous Stereocenters
作者:Guilong Li、Matthew J. Kaplan、Lukasz Wojtas、Jon C. Antilla
DOI:10.1021/ol100378t
日期:2010.5.7
Dihydropyran derivatives readily undergo addition to N-acyl imines in the presence of chiral phosphoric acids. This addition process yields an attractive product that is capable of a tandem oxidative-cyclization via an epoxide intermediate.
Catalytic Asymmetric Addition of Alcohols to Imines: Enantioselective Preparation of Chiral <i>N</i>,<i>O</i>-Aminals
作者:Guilong Li、Frank R. Fronczek、Jon C. Antilla
DOI:10.1021/ja8033334
日期:2008.9.17
The enantioselectiveaddition of alcohols to imine electrophiles has been shown to proceed in the presence of a catalytic amount of a chiral phosphoric acid catalyst. The reaction allows for the formation of the respective chiral N,O-aminals in excellent yield and enantioselectivity. A total of 11 different alcohols and 11 different imines were successfully used as a clear demonstration of the reaction