Base-promoted ring-closing carbonyl–allene metathesis for the synthesis of 2,4-disubstituted pyrroles
作者:Guolin Cheng、Weiwei Lv、Lulu Xue
DOI:10.1039/c8gc01675e
日期:——
A base-promoted ring-closing carbonyl–allene metathesis reaction of N-allenyl β-enaminones (generated in situ from N-propargyl β-enaminones) gives 2,4-disubstituted pyrroles with cleavage of the C(sp)–C(sp3) bond. This transition metal-free procedure generates 1 equiv. of acetic acid as the sole byproduct. A preliminary mechanistic study supports a stepwise [2 + 2] cycloaddition/retro [2 + 2] reaction
Gold-catalysed cyclisation of N-propargylic β-enaminones to form 3-methylene-1-pyrroline derivatives
作者:Kommuru Goutham、N. S. V. M. Rao Mangina、Surisetti Suresh、Pallepogu Raghavaiah、Galla V. Karunakar
DOI:10.1039/c3ob42513d
日期:——
A gold(i) catalysed reaction between N-propargylic β-enaminones and arynes was developed to access 3-methylene-1-pyrrolines. The title compounds were obtained in 57–78% yields.
<scp>Base‐Promoted</scp>
Synthesis of
<scp>3‐Alkenyl</scp>
‐2‐pyridones from
<scp>
<i>N</i>
‐Propargyl
</scp>
‐β‐enaminones and Aryl Aldehydes
作者:Qingyu Tian、Shangyun Xiao、Guolin Cheng
DOI:10.1002/cjoc.202100331
日期:2021.10
In this article, we report a base-promoted sequential cyclization/aldol-type condensation/isomerization cascade reaction of N-propargyl-β-enaminones with aryl aldehydes. The key step in this protocol is the generation of 1,4-oxazepine anions from N-propargyl-β-enaminones under basic conditions, which are captured by aryl aldehydes. The method allows the formation of one pyridone core and one C—C double