Synthesis of 5,6‐Dihydropyrazolo[5,1‐
<i>a</i>
]isoquinoline and Ethyl (
<i>Z</i>
)‐3‐Acetoxy‐3‐tosylpent‐4‐enoate through Tertiary‐Amine‐Catalyzed [3+2] Annulation
作者:Yu Lei、Jiao‐Jiao Xing、Qin Xu、Min Shi
DOI:10.1002/ejoc.201600577
日期:2016.7
catalyzed divergent [3+2] annulation of C,N-cyclic azomethineimines with δ-acetoxyallenoates was developed; 5,6-dihydropyrazolo[5,1-a]isoquinolines and ethyl (Z)-3-acetoxy-3-tosylpent-4-enoates were afforded in moderate to good yields in a one-pot manner under mild conditions. This annulation reaction provides a highly efficient method to construct dinitrogen-fusedheterocycles and ethyl (Z)-3-ace
[3,3]-Sigmatropic rearrangement of allenic alcohols: stereoselective synthesis of 1,3-diene-2-ol sulfonates
作者:Yuyang Zhao、Yurong Wang、Zhanshou Gu、Zhiming Wang
DOI:10.1039/c7ob00578d
日期:——
An efficient synthetic pathway to 1,3-diene-2-ol sulfonates involving the [3,3]-sigmatropic rearrangement of allenic alcohols with sulfonic acids under mild reaction conditions is described. These products can easily undergo reduction or transition-metal catalyzed cross-coupling reactions to yield a series of stereodefined multisubstituted 1,3-dienes.
NHC-catalyzed formal [3 + 3] annulations of δ-acetoxy allenoates for the synthesis of 4<i>H</i>-pyran derivatives
作者:Bai Shi、Fangyi Jin、Qi Lv、Xinrong Zhou、Zhixiao Liao、Chenxia Yu、Kai Zhang、Changsheng Yao
DOI:10.1039/d3ob00732d
日期:——
Herein, an N-heterocyclic carbene (NHC) catalyzed formal [3 + 3] annulation of δ-acetoxy allenoates with 1C,3O-bisnucleophiles for the construction of 4H-(fused)pyrans has been developed.
Regio- and Stereoselective Synthesis of 2-Amino-dienes via Decarboxylative Amination of 4-(Ethoxycarbonyl)-2,3-allenols by TsNCO
作者:Lijun Wu、Hui Huang、Yun Liang、Pi Cheng
DOI:10.1021/jo502098b
日期:2014.11.21
A metal-free decarboxylative amination of 4-(ethoxycarbonyl)-2,3-allenols by TsNCO via base-induced aza-Michael addition/elimination has been developed. A variety of substituted N-tosyl 1,3-dien-2-yl amines were obtained in good yields and excellent regio- and stereoselectivity. Moreover, this transformation could be applied in preparation of 2-amino-trienes.