Total syntheses of (+)- and (−)-Crinane via Pd(0)-Catalyzed deacylative allylation
作者:Mrinal K. Das、Abhinay Yadav、Satyajit Majumder、Ayan Mondal、Alakesh Bisai
DOI:10.1016/j.tet.2021.131928
日期:2021.2
readily available allylic alcohols (pro-electrophiles) by employing Pd(0)-catalysis under mild reaction conditions. The methodology can be extended for deacylative benzylations (DaB) of enolcarbonates of 2-arylcyclohexanones. As an application of our methodology, we have shown asymmetrictotalsynthesis of Amaryllidaceae alkaloids, (+)- and (−)-crinane.
Formation of a Quaternary Carbon Center through the Pd(0)/PhCOOH-Catalyzed Allylation of Cyclic β-Keto Esters and 1,3-Diketones with Alkynes
作者:Nitin T. Patil、Yoshinori Yamamoto
DOI:10.1021/jo0490144
日期:2004.9.1
Formation of a quaternarycarboncenter through the allylation of β-ketoesters and 1,3-diketones with alkynes is accomplished by the use of Pd(0)/benzoic acid catalyst. Reactions of various cyclic β-ketoesters and 1,3-diketones with alkynes in the presence of Pd2dba3·CHCl3 (5 mol %), PPh3 (40 mol %), and PhCOOH (10 mol %) proceeded at 100 °C in toluene (5 M) to give the corresponding allylation products
A dual platinum‐ and pyrrolidine‐catalyzed direct allylic alkylation of allylic alcohols with various activemethylenecompounds to produce products with high monoallylation selectivity was developed. The use of pyrrolidine and acetic acid was essential, not only for preventing undesirable side reactions, but also for obtaining high monoallylation selectivity.
α-allyl-γ-butyrolactone 9 either undergoes cyclisation to give the alcoholic cyclopentenone 12 or 1,2-acyl migration to give 13, when subjected to treatment with LDA in THF/TMEDA. An effective strategy to nullify this directive influence, and dictate cyclisation, is exemplified in a model synthesis of spiro[4,5]dec-2-ene-1,6-dione 19 by a one-pot tandem cyclisation — elimination process starting from 16
Synthesis and Ring‐Closing Reactions of Aminocyclohexane Derivatives Bearing Unsaturated Side Chains at C2: Stereocontrolled Approaches to cis‐ and trans‐Fused Perhydro‐indoles and ‐quinolines
作者:Xingxing Xing、Yu‐Tao He、Jian‐Guo Song、Ping Lan、Lorenzo V. White、Shen Tan、Le Nhan Pham、Michelle L. Coote、Xin Wu、Martin G. Banwell
DOI:10.1002/ejoc.202400455
日期:——
Two epimeric pairs of N-protected cyclohexamines bearing acrylate residues attached at C2 have been investigated for their capacities to undergo base-promoted intramolecular aza-Michael addition reactions. Three of these substrates do so both efficiently and completely diastereoselectively. Simple manipulation of the product perhydroindoles and decahydroquinolines afford ready access to novel analogues
已经研究了在C2处连接有丙烯酸酯残基的两个差向异构对的N-保护的环六胺进行碱促进的分子内氮杂-迈克尔加成反应的能力。其中三种底物既有效又完全非对映选择性地这样做。对产品全氢吲哚和十氢喹啉进行简单操作,即可轻松获得强效神经毒素普米利奥毒素 C 的新型类似物。