Mild, Efficient, and Robust Method for Stereocomplementary Iron-Catalyzed Cross-Coupling Using (E)- and (Z)-Enol Tosylates
Mild, Efficient, and Robust Method for Stereocomplementary Iron-Catalyzed Cross-Coupling Using (E)- and (Z)-Enol Tosylates
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DOI：
10.1055/s-0030-1258131
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发表时间：
2010-09-01
期刊：
影响因子：
2
通讯作者：
Tanabe, Yoo
中科院分区：
文献类型：
--
作者：
Nishikado, Hiroshi;Nakatsuji, Hidefumi;Tanabe, Yoo
铁催化的格氏试剂（RMgX）与（E）-和（Z）-烯醇甲苯磺酸酯的交叉偶联顺利进行，得到各种相应的（E）-和（Z）-三取代的α，β-双饱和甲酯（总共30个实施例; 55-98%产率）。简单、温和、立体保留的方法使用氯化铁（FeCl 3）、乙酰丙酮铁（III）[Fe（acac）（3）]和三（二苄基甲烷）铁（III）[Fe（dbm）（3）]。（E）-和（Z）-烯醇甲苯磺酸酯容易地通过所报道的立体互补甲苯磺酰化方法从甲基β-酮酯或α-甲酰基酯制备。甲基α-甲酰基酯通过实用且稳健的TiCl 4-Et 3 N介导的甲酯与甲酸甲酯的α-取代反应获得。
Iron-catalyzed cross-coupling of Grignard reagents (RMgX) with (E)- and (Z)-enol tosylates proceeded smoothly to give a variety of the corresponding (E)-and (Z)-trisubstituted alpha,beta-bunsaturated methyl esters (total 30 examples; 55-98% yield). The simple, mild, stereoretentive method utilized iron(III) chloride (FeCl3), iron(III) acetylacetonate [Fe(acac)(3)], and iron(III) tris(dibenzylmethane) [Fe(dbm)(3)]. The (E)-and (Z)-enol tosylates were readily prepared by the reported stereocomplementary tosylation method from methyl beta-keto esters or alpha-formyl esters. Methyl alpha-formyl esters were obtained via a practical and robust TiCl4-Et3N-mediated alpha-formylation of methyl esters with methyl formate.