Pyrrolizidinone and indolizidinone synthesis: generation and intramolecular addition of .alpha.-acylamino radicals to olefins and allenes
作者:Duane A. Burnett、Joong Kwon Choi、David J. Hart、Yeun Min Tsai
DOI:10.1021/ja00338a033
日期:1984.12
Des radicaux α-acylamino peuvent etre generes par traitement de derives de phenylthio-2-, phenylseleno-2 ou methylthio-2 butene-3'yl-1 pyrrolidones-2 par l'hydrure de tributyl-Sn en presence de AIBN. Ces radicaux subissent des reactions intramoleculaires pour donner des indolizidinones et des pyrrolizidinones
Des radicaux α-acylamino peuvent etregeneres par traitement de 衍生 de phenylthio-2-, phenylseleno-2 oumethylthio-2 butene-3'yl-1 pyrrolidones-2 par l'hydrure de tributyl-Sn en Ces radicaux subissent des反应分子内反应donner des indolizidinones et des pyrrolizidinones
Ti-Catalyzed Straightforward Synthesis of Exocyclic Allenes
作者:Juan Muñoz-Bascón、Carmen Hernández-Cervantes、Natalia M. Padial、Míriam Álvarez-Corral、Antonio Rosales、Ignacio Rodríguez-García、J. Enrique Oltra
DOI:10.1002/chem.201304033
日期:2014.1.13
Exocyclicallenes constitute useful building blocks in organic synthesis and have recently been identified as key intermediates in the synthesis of natural products. Here the first general method for the most straightforwardsynthesis of exocyclicallenes reported to date is presented. This method is based on the Barbier‐type cyclization of propargyl halides catalyzed by titanium; a safe, abundant
Titanium- and Lewis Acid-Mediated Cyclopropanation of Imides
作者:Philippe Bertus、Jan Szymoniak
DOI:10.1021/ol062938o
日期:2007.2.1
We report a straightforward synthesis of 1-azaspirocyclopropane lactams from imides. Following the described procedure, polycyclic nitrogenheterocycles containing a cyclopropane unit could be obtained from unsaturated imides. [reaction: see text].
A concise (six-step) synthesis of the indolizidine alkaloid tashiromine (1) has been achieved. Olefin cross-metathesis was used to prepare a key functionalised allylsilane, which subsequently underwent electrophile-induced ring-closure to establish the bicyclic framework with complete control of stereochemistry.
Novel route to fused nitrogen heterocycles by olefin metathesis
作者:Stephen F. Martin、Yusheng Liao、Hui-Ju Chen、Michael Pätzel、Melissa N. Ramser
DOI:10.1016/0040-4039(94)88060-3
日期:1994.8
A novel technique for the efficient synthesis of fused nitrogen heterocycles has been developed that features the molybdenum alkylidene-catalyzed metathesis of α,ω-dienes containing a nitrogen atom in the chain linking the two olefinic functional groups. The starting materials may be readily prepared in three steps from succinimide and glutarimide via sequential Mitsunobu alkylation, sodium borohydride