Reaction of Diketene with Grignard Reagents in the Presence of Cobalt Catalyst. A Convenient Method for the Synthesis of 3-Methylenealkanoic Acids Leading to Terpenoids
Primary alkyl Grignardreagents react regioselectively with diketene in the presence of cobalt(II) iodide to afford 3-methylenealkanoic acids in good yields. The synthetic utility of this reaction is demonstrated in the syntheses of terpenoids by two methods. Utilizing the isomerization of double bond of 3-methylenealkanoic acids, geranic acid and farnesic acid were obtained in two steps. Another method
在碘化钴 (II) 存在下,伯烷基格氏试剂与双烯酮发生区域选择性反应,以良好的收率得到 3-亚甲基链烷酸。该反应的合成效用在通过两种方法合成萜类化合物中得到证明。利用3-亚甲基链烷酸双键异构化,分两步得到香叶酸和法呢酸。另一种方法,即相应烯丙基酯的串联 [3,3] sigmatropic 重排用于合成 C18-天竺葵保幼激素。
Enantioselective hydrogenations of a terpenic acrylic acid catalyzed by rhodium complexes of chiral diphosphines
作者:Donald Valentine、Ruen C. Sun、Katherine Toth
DOI:10.1021/jo01306a032
日期:1980.8
Palladium-Catalyzed Cross-Coupling of 3-Iodobut-3-enoic Acid with Organometallic Reagents. Synthesis of 3-Substituted But-3-enoic Acids
3-Substituted but-3-enoic acids were obtained in good yields under mild experimental conditions by palladium-catalyzed cross-coupling of 3-iodobut-3-enoic acid with organozinc or organotin compounds using PdCl2(MeCN)(2) as catalyst and DMF as solvent.
Neutral iridium catalysts with chiral phosphine-carboxy ligands for asymmetric hydrogenation of unsaturated carboxylic acids
We developed neutral iridium catalysts with chiral spiro phosphine-carboxy ligands (SpiroCAP) for asymmetrichydrogenation of unsaturated carboxylic acids. Different from the cationic Crabtree-type catalysts, the iridium catalysts with chiral spiro phosphine-carboxy ligands are neutral and do not require the use of a tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BArF−) counterion, which is necessary