In this work, six novelaxiallyunfixed biaryl‐based water‐compatible bifunctionalorganocatalysts were designed and synthesized for the organocatalytic access to a variety of 3‐alkyl‐3‐hydroxy‐2‐oxindole derivatives via aldol reactions in water. Organocatalyzed by 5a, the direct aldol reactions of isatins with enolisable ketones underwent readily in water, furnishing the structurally diverse 3‐al
Unraveling and Manipulating the Stereospecific Retro-Aldol Reaction in the Organocatalytic Asymmetric Aldol Reaction of Isatin and Cyclohexanone
作者:Jing Wang、Zhi-Xiong Deng、Chao-Ming Wang、Peng-Ju Xia、Jun-An Xiao、Hao-Yue Xiang、Xiao-Qing Chen、Hua Yang
DOI:10.1021/acs.orglett.8b03292
日期:2018.12.7
An l-pyroglutamic acid-derived bifunctional organocatalyst was designed and applied in an organocatalyticasymmetric direct aldolreaction between isatins and cyclohexanone, in which an erosion of enantiomeric excess of aldol adduct was unexpectedly observed. Through closely monitoring the reaction and performing extensive control experiments, it was determined that the erosion of ee was attributed
EnantioselectiveAldol Reaction Between Isatins and Cyclohexanone Catalyzed by Amino Acid Sulphonamides
作者:Jun Wang、Qi Liu、Qing Hao、Yanhua Sun、Yiming Luo、Hua Yang
DOI:10.1002/chir.22433
日期:2015.4
Sulphonamides derived from primary α‐aminoacid were successfully applied to catalyze the aldolreaction between isatin and cyclohexanone under neat conditions. More interestingly, molecular sieves, as privileged additives, were found to play a vital role in achieving high enantioselectivity. Consequently, high yields (up to 99%) along with good enantioselectivities (up to 92% ee) and diastereoselectivities
<i>In Situ</i>Formed Bifunctional Primary Amine-Imine Catalyst: Application to the Construction of Chiral Tertiary Alcohols through Asymmetric Aldol-Type Reaction
An in situ formation method to obtain chiral bifunctionalprimary amine‐imine catalysts from the C2‐symmetric chiral diimines has been developed. The efficiency of this method in the construction of chiral tertiary alcohols which are valuable pharmaceutical intermediates is proved by its application to the asymmetricaldol‐type reaction of cyclic ketones with other activated ketone compounds as the
Highly enantioselective synthesis of 3-cycloalkanone-3-hydroxy-2-oxindoles, potential anticonvulsants
作者:Monika Raj、Nagarathanam Veerasamy、Vinod K. Singh
DOI:10.1016/j.tetlet.2010.02.082
日期:2010.4
Highly enantioselective catalytic synthesis of 3-cycloalkanone-3-hydroxy-2-oxindoles was achieved by using primary-tertiary diamine-Brønsted acid catalyst in both organic medium and aqueous medium. The products, thus obtained act as potentialanticonvulsants.