Catalytic Z-selective olefin cross-metathesis for natural product synthesis
作者:Simon J. Meek、Robert V. O’Brien、Josep Llaveria、Richard R. Schrock、Amir H. Hoveyda
DOI:10.1038/nature09957
日期:2011.3
biologically active molecules, and there are a large number of chemical transformations in which alkenes act as the reactants or products (or both) of the reaction. Many alkenes exist as either the E or the higher-energy Z stereoisomer. Catalytic procedures for the stereoselective formation of alkenes are valuable, yet methods enabling the synthesis of 1,2-disubstituted Z alkenes are scarce. Here we report catalytic
烯烃存在于许多生物活性分子中,并且存在大量化学转化,其中烯烃作为反应的反应物或产物(或两者)。许多烯烃以 E 或更高能量的 Z 立体异构体形式存在。用于立体选择性形成烯烃的催化程序很有价值,但能够合成 1,2-二取代 Z 烯烃的方法很少。在这里,我们报告了以前未报道过的末端烯醇醚和烯丙基酰胺的催化 Z 选择性交叉复分解反应,直到现在仅用于 E 选择性过程。相应的二取代烯烃以高达 >98% 的 Z 选择性和 97% 的产率形成。这些转化由含有丰富且廉价的金属钼的催化剂促进,适合克级操作。使用减压是实现高立体选择性的一种简单有效的策略。该方法的效用通过其在抗氧化缩醛磷脂磷脂和强效免疫刺激剂 KRN7000 的合成中得到证明,该磷脂存在于电活性组织中并与阿尔茨海默病有关。
Synthesis of <i>Z</i>-(Pinacolato)allylboron and <i>Z</i>-(Pinacolato)alkenylboron Compounds through Stereoselective Catalytic Cross-Metathesis
作者:Elizabeth T. Kiesewetter、Robert V. O’Brien、Elsie C. Yu、Simon J. Meek、Richard R. Schrock、Amir H. Hoveyda
DOI:10.1021/ja403188t
日期:2013.4.24
first examples of catalytic cross-metathesis (CM) reactions that furnish Z-(pinacolato)allylboron and Z-(pinacolato)alkenylboron compounds are disclosed. Products are generated with high Z selectivity by the use of a W-based monoaryloxide pyrrolide (MAP) complex (up to 91% yield and >98:2 Z:E). The more sterically demanding Z-alkenylboron species are obtained in the presence of Mo-based MAP complexes
公开了提供Z-(频哪醇)烯基硼和Z-(频哪醇)烯基硼化合物的催化交叉复分解(CM)反应的第一实例。通过使用 W 基单芳氧基吡咯 (MAP) 络合物,生成具有高 Z 选择性的产品(产率高达 91%,Z:E >98:2)。在 Mo 基 MAP 配合物存在下,可以获得空间要求更高的 Z-烯基硼物质,产率高达 93%,Z 选择性高达 97%。首次报道了 1,3-二烯和芳基烯烃的 Z 选择性 CM。该方法与催化交叉偶联相结合的实用性通过抗癌剂考布他汀 A-4 的简洁和立体选择性合成得到了证明。
EFFICIENT METHODS FOR Z- OR CIS-SELECTIVE CROSS-METATHESIS
申请人:Hoveyda Amir H.
公开号:US20110245477A1
公开(公告)日:2011-10-06
The present invention generally relates to methods for performing metathesis reactions, including cross-metathesis reactions. Methods described herein exhibit enhanced activity and stereoselectivity, relative to known methods, and are useful in the synthesis of a large assortment of biologically and therapeutically significant agents.
Efficient methods for Z- or cis-selective cross-metathesis
申请人:Hoveyda Amir H.
公开号:US08552242B2
公开(公告)日:2013-10-08
The present invention generally relates to methods for performing metathesis reactions, including cross-metathesis reactions. Methods described herein exhibit enhanced activity and stereoselectivity, relative to known methods, and are useful in the synthesis of a large assortment of biologically and therapeutically significant agents.