The asymmetric synthesis of β-aryl-α-hydroxy esters from β-aryl-α,β-dihydroxy esters
摘要:
alpha,beta-Dihydroxy-beta-aryl esters obtained via Sharpless asymmetric dihydroxylation (AD) of substituted cinnamate esters are reduced by sequential reaction with trimethyl orthoacetate and acetyl bromide followed by catalytic hydrogenolysis in methanol to give enantiomerically enriched beta-aryl-alpha-hydroxy esters. (C) 2002 Elsevier Science Ltd. All rights reserved.
Trifluoromethanesulfonic Acid Catalyzed Alkylation of Arenes with Methyl (2R)-Glycidate
作者:Pablo J. Linares-Palomino、G. K. Surya Prakash、George A. Olah
DOI:10.1002/hlca.200590102
日期:2005.6
Methyl (R)-glycidate (=methyl (R)-oxiranecarboxylate; 2) in superacidic trifluoromethanesulfonicacid medium reacts with electron-rich arenes to give α-hydroxy-β-arylpropanoate derivatives 3a–3f with high stereospecificity. At the same time, the observed high regioselectivity has been attributed to superelectrophilic activation of the glycidate.
Asymmetric transfer hydrogenation of α-azido acrylates
作者:Yang Ji、Ping Xue、Dan-Dan Ma、Xue-Qiang Li、Peiming Gu、Rui Li
DOI:10.1016/j.tetlet.2014.11.072
日期:2015.1
The asymmetric transfer hydrogenation of alpha-azido acrylates has been explored, a range of alpha-hydroxy esters are produced with good enantioselectivities (80-90% ee). The reaction was conducted in the wet HCO2H/NEt3 with Ru-TsDPEN A. (C) 2014 Elsevier Ltd. All rights reserved.
The asymmetric synthesis of β-aryl-α-hydroxy esters from β-aryl-α,β-dihydroxy esters
作者:Nicholas J Lawrence、Stephen Brown
DOI:10.1016/s0040-4020(01)01176-0
日期:2002.1
alpha,beta-Dihydroxy-beta-aryl esters obtained via Sharpless asymmetric dihydroxylation (AD) of substituted cinnamate esters are reduced by sequential reaction with trimethyl orthoacetate and acetyl bromide followed by catalytic hydrogenolysis in methanol to give enantiomerically enriched beta-aryl-alpha-hydroxy esters. (C) 2002 Elsevier Science Ltd. All rights reserved.
Catalytic Enantioselective Synthesis of Difluorinated Alkyl Bromides
作者:Mark D. Levin、John M. Ovian、Jacquelyne A. Read、Matthew S. Sigman、Eric N. Jacobsen
DOI:10.1021/jacs.0c07043
日期:2020.9.2
facilitated the development of an improved catalyst providing higher enantioselectivity with lower catalyst loadings. The versatility of the difluoroalkyl bromide products was demonstrated via highly enantiospecific substitution reactions with suitably reactive nucleophiles. The origins of enantioselectivity were investigated using computed interaction energies of simpli-fied catalyst and substrate structures