simple substrates. However, they usually involve the employment of organic halides and suffer from toxic or environmental issues. We report an efficient and environmentally benign methodology—aerobic oxidative cross-coupling of primary and secondary alcohols—to directly produce α,β-unsaturated ketones that are key intermediates for synthesis of agrochemical, pharmaceutical, and other fine chemicals. A noble-metal-free
C–C键形成反应在化学中对于从容易获得的简单底物构建复杂大分子非常重要。但是,它们通常涉及有机卤化物的使用,并且具有毒性或环境问题。我们报告了一种有效且对环境无害的方法-伯醇和仲醇的好氧氧化交叉偶联-直接生产α,β-不饱和酮,这是合成农业化学,制药和其他精细化学品的关键中间体。一种无贵金属的Co–N–C催化剂,是由钴-菲咯啉配合物在中孔碳载体上热解衍生而来的,可用于目标反应,并具有很高的催化活性(转换频率为3.8 s –1基于Co的单原子,超过了文献中的技术水平),良好的可回收性以及对各种基材的广泛适用性(28个示例)。有人建议在Co–N–C催化剂中的活性位是在石墨薄片内与N键合的Co单原子。
Chiral Aldehyde Catalysis for the Catalytic Asymmetric Activation of Glycine Esters
Chiral aldehyde catalysis is uniquely suitable for the direct asymmetric α-functionalization of N-unprotected amino acids, because aldehydes can reversibly form imines. However, there have been few successful reports of these transformations. In fact, only chiral aldehyde catalyzed aldol reactions of amino acids and alkylation of 2-amino malonates have been reported with good chiral induction. Here
Gold Catalyzed Synthesis of Substituted Furan by Intermolecular Cascade Reaction of Propargyl Alcohol and Alkyne
作者:Seyedmorteza Hosseyni、Yijin Su、Xiaodong Shi
DOI:10.1021/acs.orglett.5b02980
日期:2015.12.18
Using a combination of triazole-gold (TA-Au) and copper catalysts, the substituted furan was achieved in one pot through a three-step reactioncascade. The reaction tolerates a large substrate scope with simple starting materials. The desired di-, tri-, and tetrasubstituted furans were prepared in good to excellent yields.
A new method for synthesizing polyalkylated/arylated nicotinates is established using a condensation of enamino esters with enones in the presence of FeCl3. This method facilitates the introduction of alkyl or...
Rh-catalyzed 1,4-addition of triallyl(aryl)silanes to α,β-unsaturated carbonyl compounds
作者:Toshiyuki Kamei、Mizuho Uryu、Toyoshi Shimada
DOI:10.1016/j.tetlet.2016.03.002
日期:2016.4
4-addition of triallyl(aryl)silane to α,β-unsaturatedcarbonylcompounds was developed. Triallyl(aryl)silanes were used as air- and moisture-stable silicon nucleophiles. Allylsilanes were converted to silanols in situ and underwent transmetalation. This method can accept a wide range of functionalized triallyl(aryl)silane and α,β-unsaturatedcarbonylcompounds.