Enantioselective synthesis of N-heterocycles via intramolecular Pd(0)-catalysed allylic amination
作者:Beata Olszewska、Bogusław Kryczka、Anna Zawisza
DOI:10.1016/j.tet.2013.09.043
日期:2013.11
An efficient and stereoselective synthesis of pyrrolidine-, piperidine-, and azepane-type N-heterocycles is described by the intramolecular Pd(0)-catalysed cyclisation of amino allylic carbonates. The use of chiral ligands gave the corresponding heterocyclic derivatives having er values that were from moderate to good.
Titanium oxide-supported carbonylmolybdenum catalyst was applied to selective monoallylation of methyl p-tolylsulfonylacetate using allylic acetates or carbonates in refluxing dioxane. This reaction required both 2,2′-bipyridyl as a ligand and sodium hydride as a base for preparation of the salt of methyl p-tolylsulfonylacetate.
Diastereoselective synthesis of 2-vinylpyrrolidines and 2-vinylpiperidines by the palladium-catalysed cyclization of amino-allylic carbonates containing a chiral protecting group
An efficient diastereoselectivesynthesis of pyrrolidineand piperidine-type N-heterocycles is reported, by the intramolecular Pd(0)-catalysed cyclization of amino carbonatescontainingchiralprotectinggroup. The use of chiral auxiliary in the cyclization gave the corresponding heterocyclic derivatives in excellent yields and with good dr values.
通过分子内 Pd(0) 催化的含有手性保护基团的氨基碳酸酯的环化反应,报道了一种有效的非对映选择性合成吡咯烷和哌啶型 N-杂环。在环化中使用手性助剂以优异的产率和良好的 dr 值得到相应的杂环衍生物。
Chemoenzymatic Late‐Stage Modifications Enable Downstream Click‐Mediated Fluorescent Tagging of Peptides
作者:Alessandro Colombano、Luca Dalponte、Sergio Dall'Angelo、Claudia Clemente、Mohannad Idress、Ahmad Ghazal、Wael E. Houssen
DOI:10.1002/anie.202215979
日期:——
suitable for copper-catalyzed azide-alkyne cycloaddition, metathesis, and inverse-electron-demand Diels-Alder (IEDDA) reactions. A 10-mer tryptophan-containing macrocyclic peptide was tailored by AcyF, and the resulting modified peptide was successfully labelled with a tetrazine–fluorescein conjugate by IEDDA.
Synthesis of a <i>trans</i>,<i>syn</i>,<i>trans</i>-Dodecahydrophenanthrene via a Bicyclic Transannular Diels−Alder Reaction: Intermediate for the Synthesis of Fusidic Acid
作者:Michael E. Jung、Ting-Hu Zhang、Rebecca M. Lui、Osvaldo Gutierrez、K. N. Houk
DOI:10.1021/jo101533h
日期:2010.10.15
While thermolysis of the macrobicyclic triene lactone 12 did not produce the expected bicyclic transannular Diels-Alder (BTADA) product 13. heating the corresponding ether 18 to 110 degrees C for 4 h afforded a quantitative yield ol the desired cycloadduct 19. which could be easily reduced to the perhydrophenanthrene. an ABC ring analogue of lusidic acid 1 Theoretical calculations with hybrid density functional theory (B3LYP/6-31G(d)) help rationalize why the lactone does not cyclize whereas the ether does