885053-34-9Relevant articles and documents
Highly efficient C-C bond-forming reactions in aqueous media catalyzed by monomeric vanadate species in an apatite framework
Hara, Takayoshi,Kanai, Satoko,Mori, Kohsuke,Mizugaki, Tomoo,Ebitani, Kohki,Jitsukawa, Koichiro,Kaneda, Kiyotomi
, p. 7455 - 7462 (2006)
A calcium vanadate apatite (VAp), in which PO43- of hydroxyapatite (HAP), Ca10(PO4)6(OH) 2, is completely substituted by VO43- 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.