[2,3]-Wittig rearrangements of (E)-3-aza-allylic alcoholderivatives can provide access to syn or anti optically enriched 1,2-aminoalcohols by using a chirality transfer or a chiral auxiliary.
Ireland–Claisen rearrangement of ynamides: stereocontrolled synthesis of 2-amidodienes
作者:Stephen J. Heffernan、David R. Carbery
DOI:10.1016/j.tetlet.2012.07.088
日期:2012.9
The Ireland–Claisenrearrangement of propargyl ynamido ester substrates is reported. The expected allenamide carboxylic acid products from [3,3]-sigmatropic rearrangement are not isolated, with 2-amidodienes alternatively formed in good yield with high levels of stereocontrol after decarboxylation.
Ynesulfonamide-Based Silica Gel and Alumina-Mediated Diastereoselective Cascade Cyclizations to Spiro[indoline-3,3′-pyrrolidin]-2-ones under Neat Conditions
spiro[indoline‐3,3′‐pyrrolidin]‐2‐ones were synthesized via a silica gel and alumina‐mediated sequential transformation based on tryptamine‐derived ynesulfonamide substrates under neat conditions. The inherent tendency of C−C bond migration through Wagner‐Meerwein rearrangement in the synthesis of spirooxindole was prevented by water trapping to the spiroindoleninium intermediate. The functional group tolerances
Total Syntheses of Aspidospermidine, <i>N</i>-Methylaspidospermidine, <i>N</i>-Acetylaspidospermidine, and Aspidospermine via a Tandem Cyclization of Tryptamine-Ynamide
Stork-enamine alkylation of 1H-pyrrolo[2,3-d]carbazole derivatives, which were prepared through a Brønsted acid-catalyzed tandem cyclization of tryptamine-ynamide. The scalable synthesis of 1H-pyrrolo[2,3-d]carbazole afforded facile access and a practical approach to the Aspidosperma indolealkaloid family.
aspidospermidine、N- methylaspidospermidine、N- acetylaspidospermidine 和aspidospermine的全合成是从一个常见的五环二氢吲哚中间体实现的。常见的五环二氢吲哚中间体是通过 1 H-吡咯并[2,3- d ]咔唑衍生物的 Stork-烯胺烷基化以克规模合成的,这些衍生物是通过布朗斯台德酸催化的色胺-炔酰胺串联环化制备的。1 H-吡咯并[2,3- d ]咔唑的可扩展合成为曲霉属吲哚生物碱家族提供了简便的途径和实用的方法。
Gold-Catalyzed Intramolecular Tandem Cyclization of Indole-Ynamides: Diastereoselective Synthesis of Spirocyclic Pyrrolidinoindolines
作者:Nan Zheng、Yuan-Yuan Chang、Li-Jie Zhang、Jian-Xian Gong、Zhen Yang
DOI:10.1002/asia.201500865
日期:2016.2
A gold‐catalyzed intramoleculartandemcyclization of indole‐ynamide affords tetracyclic spirocyclicpyrrolidinoindoline bearing an all‐carbon quaternary stereocentre in a single step; however, when the reaction was carried out in the presence of BF3⋅Et2O, the corresponding tricyclic spirocyclicpyrrolidinoindoline‐based enones are produced through a key 1,5‐hydride shift. The developed chemistry provides