Highly Efficient C-C Bond-Forming Reactions in Aqueous Media Catalyzed by Monomeric Vanadate Species in an Apatite Framework

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• 作者：Takayoshi Hara ; Satoko Kanai ; Kohsuke Mori ; Tomoo Mizugaki ; Kohki Ebitani ; Koichiro Jitsukawa ; Kiyotomi Kaneda
• 刊名：Journal of Organic Chemistry
• 出版年：2006
• 出版时间：September 15, 2006
• 年：2006
• 卷：71
• 期：19
• 页码：7455 - 7462
• 全文大小：306K
• 年卷期：v.71,no.19(September 15, 2006)
• ISSN：1520-6904

文摘

A calcium vanadate apatite (VAp), in which PO₄^3- of hydroxyapatite (HAP), Ca₁₀(PO₄)₆(OH)₂, iscompletely substituted by VO₄^3- in the apatite framework, was synthesized. Physicochemical analysis ofthe VAp reveals the presence of isolated VO₄ tetrahedron units with a pentavalent oxidation state. TheVAp acts as a high-performance heterogeneous base catalyst for various carbon-carbon bond-formingreactions such as Michael and aldol reactions in aqueous media and the H-D exchange reactions usingdeuterium oxide. For example, a 200-mmol-scale Michael reaction under triphasic conditions proceededrapidly, with an extremely high turnover number of up to 260 400 and an excellent turnover frequencyof 48 s^-1. No vanadium leaching was detected during the above reactions, and the catalyst was readilyrecycled with no loss of activity.