Copper catalyzed/mediated direct B–H alkenylation/alkynylation in carboranes
作者:Yu Chen、Yik Ki Au、Yangjian Quan、Zuowei Xie
DOI:10.1007/s11426-018-9388-3
日期:2019.1
B–H functionalization has been achieved. Under the assistance of a bidentate directing group, Cu-catalyzed [4+2] annulation of carboranyl amides with internal alkynes affords unprecedented C,B-substituted carborane-fused-pyridone derivatives, whereas the use of terminal alkynes leads to B–H/C(sp)–H dehydrocoupling products. The isolation and structural identification of a notably stable Cu(I) intermediate
Oxidation of Dihydrazones of Diaryl α-Diketones to Diarylacetylenes Using Sodium Periodate
作者:Balaram S. Takale、Vikas N. Telvekar
DOI:10.1246/cl.2010.1279
日期:2010.12.5
Oxidation of dihydrazones of α-diketones to acetylene was investigated by using sodium periodate. Further, the described method is also found to be suitable for deprotection of monohydrazones of al...
使用高碘酸钠研究了 α-二酮的二腙氧化成乙炔。此外,还发现所描述的方法适用于 al 的单腙的脱保护。
Palladium-Catalyzed Intermolecular Trans-Selective Carbofunctionalization of Internal Alkynes to Highly Functionalized Alkenes
carbofunctionalization of internal alkynes has been established herein. This method proceeds through a formal anti-carbopalladation, forming trans-alkenyl palladium species, which was trapped by aryl boronic acids to provide all-carbon tetrasubstituted alkenes in 32–92% yields. The trans-selective arylsilylation/remote C–H silylation and hydroarylation/remote C–H borylation of internal alkynes were also achieved using
<scp>Palladium‐Catalyzed</scp>
Oxidative Annulation of
<scp>
1‐Hydroxy‐
<i>o</i>
‐Carborane
</scp>
with Internal Alkynes: Facile Synthesis of
<scp>Carborane‐Fused</scp>
Oxaboroles
<sup>†</sup>
作者:Ruofei Cheng、Zaozao Qiu、Zuowei Xie
DOI:10.1002/cjoc.202000307
日期:2020.12
catalyzed oxidative annulation of 1‐hydroxy‐o‐carborane with internal alkynes via regioselective B(3)—H bond activation has been developed for facile synthesis of a series of C,B‐substituted carborane‐fused oxaboroles. These molecules can undergo intramolecularoxidative dehydrogenative coupling to afford carborane‐fused large π systems for potential applications in organic materials. The reaction mechanism
Alkynes and phenoldiazoniumsalts undergo a Pd‐catalyzed [2+2+1] cyclization reaction to spiro[4,5]decatetraene‐7‐ones. This structure was confirmed for one example by X‐ray single‐crystal structure analysis. The reaction is believed to proceed through oxidative addition of the phenoldiazonium cation to Pd0, subsequent insertion of two alkynes, followed by irreversible spirocyclization.