Formation of Enehydrazine Intermediates through Coupling of Phenylhydrazines with Vinyl Halides: Entry into the Fischer Indole Synthesis
作者:Fuxu Zhan、Guangxin Liang
DOI:10.1002/anie.201207173
日期:2013.1.21
Cut to the chase: Direct formation of an enehydrazine, an intermediate in the classic Fischerindolesynthesis, solves the regioselectivity problem associated with indolization. This approach not only achieves selective synthesis of indoles through proper selection of the vinyl halide, but also leads to quick construction of desoxyeseroline and esermethole, as well as the key structural motif in the
A novel α,β-unsaturated nitrone-aryne [3+2] cycloaddition and its application in the synthesis of the cortistatin core
作者:Mingji Dai、Zhang Wang、Samuel J. Danishefsky
DOI:10.1016/j.tetlet.2008.09.019
日期:2008.11
We describe here a novel alpha,beta-unsaturated nitrone-aryne [3+2] cycloaddition. The resulting benzoisoxazolines underwent N-O bond reduction-elimination-electrocyclization sequence to furnish a variety of polysubstituted 2H or 2-alkylated-1-benzo-pyrans. The application of this methodology was further demonstrated in the synthesis of the oxa[3.2.1]octene moiety of cortistatin A.
我们在这里描述了一种新型的 α、β-不饱和硝酮-芳烃 [3+2] 环加成反应。所得苯并异恶唑啉经历 NO 键还原-消除-电环化序列,以提供各种多取代的 2H 或 2-烷基化-1-苯并-吡喃。这种方法的应用在皮质抑素 A 的 oxa[3.2.1] 辛烯部分的合成中得到了进一步证明。
Gold-Catalyzed Oxidative Cyclizations of<i>cis</i>-3-En-1-ynes To Form Cyclopentenone Derivatives
作者:Sabyasachi Bhunia、Satish Ghorpade、Deepak B. Huple、Rai-Shung Liu
DOI:10.1002/anie.201108027
日期:2012.3.19
Golden tendencies: The title reaction for synthesizing cyclopentenonederivatives utilizes a gold complex and 8‐methylquinoline oxide as the catalyst system (see scheme; IPr=1,3‐bis(diisopropylphenyl)imidazol‐2‐ylidene). Such products are not attainable using diazocarbonyl reagents, as the gold carbenoids tend to react with CH bonds.
The 12-s-cis conformationally locked 11-cis-retinoids: a delineation of the thermal requirements for [1,5]-sigmatropic shifts and electrocyclizations in the vitamin A series and novel spectral properties
作者:Roshantha A. S. Chandraratna、Ann L. Bayerque、William H. Okamura