A Brønsted Acid Catalyst for the Enantioselective Protonation Reaction
作者:Cheol Hong Cheon、Hisashi Yamamoto
DOI:10.1021/ja8041542
日期:2008.7.1
A highly reactive and robust chiral Brønstedacidcatalyst, chiral N-triflyl thiophosphoramide, was developed. The first metal-free Brønstedacid catalyzed enantioselective protonation reaction of silyl enol ethers was demonstrated using this chiral Brønstedacidcatalyst. The catalyst loading could be reduced to 0.05 mol % without any deleterious effect on the enantioselectivity.
The Silicon–Hydrogen Exchange Reaction: A Catalytic σ-Bond Metathesis Approach to the Enantioselective Synthesis of Enol Silanes
作者:Hui Zhou、Han Yong Bae、Markus Leutzsch、Jennifer L. Kennemur、Diane Bécart、Benjamin List
DOI:10.1021/jacs.0c06677
日期:2020.8.12
stoichiometric chiral reagents. We now describe a catalytic approach in which strongly acidic and confined imidodiphosphorimidates (IDPi) catalyze highly enantioselective interconversions of ketones and enol silanes. These “silicon–hydrogen exchange reactions” enable access to enantiopure enol silanes via tautomerizing σ-bond metatheses, either in a deprotosilylative desymmetrization of ketones with allyl
Laboratory Evolution of Robust and Enantioselective Baeyer−Villiger Monooxygenases for Asymmetric Catalysis
作者:Manfred T. Reetz、Sheng Wu
DOI:10.1021/ja906212k
日期:2009.10.28
and induced fit docking suggests potential randomization sites, different from all previous approaches to focused library generation. Sites harboring highly conserved proline in a loop of the WT are targeted. The most active and enantioselective mutants retain the high thermostability of the parent WT PAMO. The success of the "proline" hypothesis in the present system calls for further testing in future
Induced allostery in the directed evolution of an enantioselective Baeyer–Villiger monooxygenase
作者:Sheng Wu、Juan Pablo Acevedo、Manfred T. Reetz
DOI:10.1073/pnas.0911656107
日期:2010.2.16
accepted by the wild type. By using the known X-ray structure of PAMO, a decision was made regarding an appropriate site at which saturation mutagenesis is most likely to generate mutants capable of inducing allostery without any effector compound being present. After screening only 400 transformants, a double mutant was discovered that catalyzes the asymmetric oxidative kinetic resolution of a set of structurally
Like an enzyme: Asymmetric hydrolysis of enolesters is accomplished by chiral phase‐transfer catalysts under biphasic base hydrolysis conditions. Stoichiometric reactions support the generation of a well‐organized chiral ammonium hydroxide species (Q+OH−).