Palladium-Catalyzed α-Arylation of Enones in the Synthesis of 2-Alkenylindoles and Carbazoles
摘要:
A new unified strategy has been developed for the synthesis of substituted 2-alkenylindoles and carbazoles. The strategy uses palladium-catalyzed alpha-arylation of TES-enol ethers of enones as the key step. The method is highly regioselective, provides good yields, and is expected to have wide application.
The present invention relates to a process for stereoselective cycloaddition reactions which generally comprises a cycloaddition reaction between a pair of substrates, each either chiral or prochiral, that contain reactive &pgr;-systems, in the presence of a non-racemic chiral catalyst, to produce a stereoisomerically enriched product. The present invention also relates to novel asymmetric catalyst complexes comprising a metal and an asymmetric tridentate ligand.
Asymmetric Hetero-Diels–Alder Reaction of Danishefsky’s Dienes with α-Carbonyl Esters Catalyzed by an Indium(III)–PyBox Complex
作者:Bei Zhao、Teck-Peng Loh
DOI:10.1021/ol400841s
日期:2013.6.21
An efficient catalytic enantioselective hetero-Diels–Alderreaction of Danishefsky’s dienes with α-carbonyl esters using a chiral In(III)–pybox complex has been demonstrated. This protocol offers several advantages, including mildreaction conditions, relatively low catalyst loading, and good to excellent enantioselectivities. Furthermore, the absolute configurations of the new alkynyl-containing products
Enantioselective Formal [4+1] Cycloaddition of Diazoarylacetates and the Danishefsky’s Diene: Stereoselective Synthesis of (−)-1,13-Herbertenediol
作者:Fang Hu、Qing Zhou、Fei Cao、Wen-Dao Chu、Long He、Quan-Zhong Liu
DOI:10.1021/acs.joc.8b01546
日期:2018.10.19
electron-enriched Danishefsky-type dienes afforded highly functionalized and optically enriched cyclopentenones in excellent yields (up to 97% yield) and with good to excellent enantioselectivities (60–92% ee). (−)-1,13-Herbertenediol was successfully synthesized in an overall 25% yield employing the optically enriched cyclopentenone with an all-carbon quaternary center as the key intermediate.
Synthetic studies toward the microtubule-stabilizing agent laulimalide: synthesis of the C1–C14 fragment
作者:Geoffry T Nadolski、Bradley S Davidson
DOI:10.1016/s0040-4039(00)02116-x
日期:2001.1
The C1–C14 fragment of the paclitaxel-like antimicrotubule agent laulimalide has been synthesized in 15 steps from l-(−)-citronellal. The C9 chiral center was established using an asymmetric allylation, the dihydropyran ring was prepared through ring-closing metathesis, and the exo-methylene was incorporated using Eschenmoser's salt.
紫杉醇样抗微管药laulimalide的C 1 – C 14片段是从1-(-)-香茅醛经15步合成的。使用不对称烯丙基化建立C 9手性中心,通过闭环易位制备二氢吡喃环,并使用埃森莫瑟盐掺入外亚甲基。
Catalytic Enantioselective Total Synthesis of (−)-Platyphyllide and Its Structural Revision
作者:Shiharu Hiraoka、Shinji Harada、Atsushi Nishida
DOI:10.1021/jo1003746
日期:2010.6.4
The catalytic asymmetric totalsynthesis of platyphyllide has been accomplished. A key highly substituted cyclohexene derivative has been obtained by the catalytic asymmetric Diels−Alder reaction of Danishefsky diene with an electron-deficient alkene. The Diels−Alder adduct was converted to a protected cyclohexane-1,3-dione in chiral form by catalytic Ito−Saegusa oxidation. Although the reported structure