A Novel Synthesis of 1,3-Oxazine-2,4-diones via a Simple and Efficient Reaction of CO<sub>2</sub> with 2,3-Allenamides
作者:Guofei Chen、Chunling Fu、Shengming Ma
DOI:10.1021/ol9009046
日期:2009.7.2
A simple and efficient reaction of CO2 with 2,3-allenamides under mild conditions (CO2 balloon without any metal catalyst in the presence of K2CO3 or Cs2CO3) leads to an efficient synthesis of 1,3-oxazine-2,4-diones. The high reactivity of the allene moiety is crucial for the success of this transformation since the corresponding reaction of alpha,beta-unsaturated alkenamides or alkynamides does not occur.
Access to 1,3-oxazine-2,4-diones/1,3-thiazine-2,4-diones <i>via</i> organocatalytic CO<sub>2</sub>/COS incorporation into allenamides
作者:Hui Zhou、Rui Wang、Hui Zhang、Wei Chen、Xiao-Bing Lu
DOI:10.1039/c9ob02398d
日期:——
Lewis base-CO2/COS adducts were firstly studied as organocatalysts for [4 + 2] annulation of CO2/COS with allenamides to selectively synthesize 1,3-oxazine-2,4-diones/1,3-thiazine-2,4-diones.