Related Experiment Video
Updated: Jul 20, 2026

Rapid Mix Preparation of Bioinspired Nanoscale Hydroxyapatite for Biomedical Applications
Published on: February 23, 2017
Highly efficient C-C bond-forming reactions in aqueous media catalyzed by monomeric vanadate species in an apatite
Takayoshi Hara1, Satoko Kanai, Kohsuke Mori
1Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan.
Abstract:
A calcium vanadate apatite (VAp), in which PO4(3-) of hydroxyapatite (HAP), Ca10(PO4)6(OH)2, is completely substituted by VO4(3-) in the apatite framework, was synthesized. Physicochemical analysis of the VAp reveals the presence of isolated VO4 tetrahedron units with a pentavalent oxidation state. The VAp acts as a high-performance heterogeneous base catalyst for various carbon-carbon bond-forming reactions such as Michael and aldol reactions in aqueous media and the H-D exchange reactions using deuterium oxide. For example, a 200-mmol-scale Michael reaction under triphasic conditions proceeded rapidly, with an extremely high turnover number of up to 260 400 and an excellent turnover frequency of 48 s(-1). No vanadium leaching was detected during the above reactions, and the catalyst was readily recycled with no loss of activity.
Related Concept Videos
Cationic Chain-Growth Polymerization: Mechanism
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
Hydration of Cement
Heterogeneous Catalysis
EDTA: Auxiliary Complexing Reagents
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...

