Arylation of β-methallyl alcohol catalyzed by Pd(OAc)₂ in combination with P(t-Bu)₃: application to fragrance synthesis

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• 作者：Alberto Scrivanti ; Matteo Bertoldini ; Valentina Beghetto ; Ugo Matteoli
• 关键词：Hantzsch condensation ; One-pot synthesis ; Polyhydroquinolines ; Grinding ; Solvent-free ; Catalyst-free
• 刊名：Tetrahedron
• 出版年：2008
• 出版时间：14 January 2008
• 年：2008
• 卷：64
• 期：3
• 页码：543-548
• 全文大小：224 K

文摘

Pd(OAc)₂ in combination with P(t-Bu)₃ catalyzes the coupling of β-methallyl alcohol with 1-bromo-3,4-(methylenedioxy)benzene (1a), 1-bromo-4-methoxybenzene (1b), or 1-bromo-4-tert-butylbenzene (1c). The reaction affords the corresponding 2-methyl-3-aryl-propanals, which are valuable floral fragrances. With 1a or 1b high reaction rates are obtained at 130 °C using NMP/water mixtures and an inorganic base such as Na₂CO₃. The chemoselectivity of the reaction is almost complete, so that the process appears practically feasible. In contrast, the coupling of β-methallyl alcohol with 1c proceeds with low reaction rates.