Synthesis of Chiral α-Substituted β-Carboxyethylphosphonic Acids by Palladium-Catalyzed Hydroesterification
Siyi Zhang1, Chaoren Shen1, Xiaolei Ji1
1Chang-Kung Chuang Institute and Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai200062, P. R. China.
Abstract:
An efficient palladium-catalyzed asymmetric hydroesterification of alkenylphosphonic acids has been developed to access chiral α-substituted β-carboxyethylphosphonic acids. This atom-economical transformation employs a palladium catalyst combined with WingPhos, a rigid P-stereogenic bidentate phosphine ligand, enabling one-step construction of structurally diverse chiral phosphonic acids. The mechanistic studies demonstrate that the phosphonic acid moiety is critical for promoting the overall reactivity. A synergistic interplay between the substrate's internal acidic protons and an external Brønsted acid accelerating the generation of catalytically active palladium hydride species was revealed.
Related Concept Videos
Esters to Carboxylic Acids: Acid-Catalyzed Hydrolysis
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...
Alkylation of β-Diester Enolates: Malonic Ester Synthesis
α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction
Acid Halides to Carboxylic Acids: Hydrolysis
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic acid...
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
![Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium Under Mild Reaction Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F51444.jpg&w=3840&q=50)
