Convenient Synthesis of 3-Glycosylated Isocoumarins
作者:Kasireddy Sudarshan、Indrapal Singh Aidhen
DOI:10.1002/ejoc.201601264
日期:2017.1.3
A new route for the synthesis of 3-substituted and 8-hydroxy-3-substituted isocoumarins has been developed by using modified Julia olefination for initial C-C bond formation between aldehydes and benzylic-sulfones. Palladium-catalyzed Meinwald rearrangement was used as a key step for the obtainment of ketone intermediates, which on base promoted intramolecular cyclization afforded the desired isocoumarins
通过使用改良的 Julia 烯化在醛和苄基砜之间形成初始 CC 键,开发了一种合成 3-取代和 8-羟基-3-取代异香豆素的新途径。钯催化的 Meinwald 重排被用作获得酮中间体的关键步骤,其在基础上促进了分子内环化,得到了所需的异香豆素。所开发的方法首次为迄今为止未知的 3- 糖基异香豆素和特别是其中葡糖基部分连接到异香豆素骨架的吡喃酮环的 3- 糖基异香豆素铺平了道路。
Highly Stereoselective Hydrocarbation of Terminal Alkynes via Pt-Catalyzed Hydrosilylation/Pd-Catalyzed Cross-Coupling Reactions
作者:Scott E. Denmark、Zhigang Wang
DOI:10.1021/ol0156751
日期:2001.4.1
[GRAPHICS]The formal addition of an aryl-H or alkenyl-H bond across a terminal alkyne has been accomplished by the combination of platinum-catalyzed hydrosilylation followed by palladium-catalyzed cross-coupling, The use of the t-Bu3P-Pt(DVDS) catalyst in combination with tetramethyldisiloxane gave excellent regio- and stereoselectivity with a number of alkyne substrates, Subsequent, fluoride-promoted cross-coupling proceeded in high yield and stereospecificity for a variety of aryl halides.
Organo-cuivreux vinyliques 14. Arylation des cuprates vinyliques