Medicinal Chemistry Division, Indian Institute of Integrative Medicine (Council of Scientific & Industrial Research), Jammu, 180 001, India.
Org Biomol Chem. 2012 Feb 28;10(8):1587-97. doi: 10.1039/c1ob06660a. Epub 2012 Jan 6.
We report a new and efficient iron oxide catalyzed cross-coupling reaction between organometallic species such as alkyl/arylmagnesium halides or organolithium species and α-hydrogen bearing cyclic unbranched and branched aliphatic ethers via activation of C(sp(3))-H. In the presence of 1 mol% of iron oxide, five and six membered unbranched cyclic ethers such as tetrahydrofuran and tetrahydropyran gave good to excellent yields of cross-coupled products. Whereas, in case of branched ether such as 2-methyltetrahydrofuran, it was observed that the arylation occurred at both the sides and gave moderate yields of a mixture of regioisomers. Among the organometallic species used, alkyl organometallic reagents gave less yields as compared to aryl organometallics.
我们报道了一种新的、有效的铁氧化物催化的交叉偶联反应，该反应涉及有机金属物种，如烷基/芳基卤化镁或有机锂物种，以及α-氢取代的环状无支链和支链脂肪族醚，通过 C(sp(3))-H 的活化。在 1mol%的氧化铁存在下，五元环和六元环无支链环状醚，如四氢呋喃和四氢吡喃，得到了良好至优异的交叉偶联产物收率。然而，在支链醚如 2-甲基四氢呋喃的情况下，观察到芳基化发生在两侧，得到了区域异构体混合物的中等收率。在所使用的有机金属物种中，烷基有机金属试剂的产率低于芳基有机金属试剂。
