通过铜催化的α-氧杂环丁烯N的氧化[3 + 2]环化反应,对苯并[ e ]吲哚-4,5-二酮和萘[2,1- b ]噻吩-4,5-二酮进行化学选择一锅法。 S-乙缩醛/β-酮硫代酰胺与α-/β-萘酚
摘要:
一种操作简单有效的一锅法,用于合成1-芳酰基(或烷酰基)-2-硫烷基-3-芳基(或烷基)-3 H-苯并[ e ]吲哚-4,5-二酮和萘并[首次在露天条件下通过铜催化的α-氧杂环丁烯N,S-乙缩醛/β-酮硫酰胺与α-/β-萘酚的交叉偶联反应设计了2,1- b ]噻吩-4,5-二酮。。该转化成功的关键是室温下将α-/β-萘酚氧化为1,2-萘醌作为反应性物质,然后通过α-氧杂环丁烯N,S进行正式的[3 + 2]环化反应-缩醛/β-酮硫酰胺通过迈克尔加成/互变异构化/氧化/环化/芳香化反应的级联序列,使得能够将吡咯/噻吩环加到萘醌部分上。此外,在无溶剂条件下将苯并[ e ]吲哚-4,5-二酮转化为五环稠合的吩嗪衍生物。根据我们的实验结果,提出了该化学选择性方案的初步机理论据,该方案得到了对照实验的充分验证和支持。
In(OTf)<sub>3</sub>-catalysed one-pot versatile pyrrole synthesis through domino annulation of α-oxoketene-N,S-acetals with nitroolefins
作者:Abhijeet Srivastava、Gaurav Shukla、Anugula Nagaraju、Girijesh Kumar Verma、Keshav Raghuvanshi、Raymond C. F. Jones、Maya Shankar Singh
DOI:10.1039/c4ob00781f
日期:——
In(OTf)3-catalyzed robust and sustainable one-pot access to previously unknown and synthetically demanding polysubstituted pyrroles via [3 + 2] annulation of α-oxoketene-N,S-acetals with β-nitrostyrenes has been achieved under solvent-free conditions. The merit of this domino Michael addition/cyclization sequence is highlighted by its operational simplicity, short reaction time (5–10 min), good to
Lewis acid mediated three-component one-flask regioselective synthesis of densely functionalized 4-amino-1,2-dihydropyridines via cascade Knoevenagel/Michael/cyclization sequence
highly convergent and regioselective one-potsynthesis of hitherto unreported 4-amino-1,2-dihydropyridines has been achieved viathree-component domino coupling (3CDC) of α-oxoketene-N,S-arylaminoacetals, aldehydes, and malononitrile in the presence of InCl3 under solvent-free conditions. The merit of this cascade Knoevenagel condensation/Michael addition/cyclization sequence is highlighted by its atom-economy
Direct Construction of 2-Aryliminochromenes from Arynes, <i>N</i>,<i>S</i>-Keteneacetals, and DMF
作者:Li-Rong Wen、Ning-Ning Man、Wen-Kui Yuan、Ming Li
DOI:10.1021/acs.joc.6b00843
日期:2016.7.15
A concise and direct synthetic strategy for the construction of 2-aryliminochromene skeleton by cascade three-component coupling reaction of arynes, N,S-keteneacetals, and DMF in good yields has been disclosed. The process demonstrates the first example of aryne chemistry combined with N,S-keteneacetals. Using this strategy, an expeditious synthesis of biologically important arylimino-2H-chromene-3-
已经公开了通过芳烃,N,S-酮缩醛和DMF的级联三组分偶联反应以良好的产率构建2-芳基亚甲基苯胺骨架的简明而直接的合成策略。该方法证明了芳烃化学与N,S-烯酮缩醛结合的第一个例子。使用这种策略,可以快速合成生物学上重要的arilimino-2 H -chromene-3-羧酰胺。
Catalyst-Controlled Straightforward Synthesis of Highly Substituted Pyrroles/Furans via Propargylation/Cycloisomerization of α-Oxoketene-N,S-acetals
作者:Ganesh Chandra Nandi、Soumini K
DOI:10.1021/acs.joc.6b02367
日期:2016.12.2
A facile and efficient InCl3 catalyzed one-pot synthesis of highly substituted pyrroles has been developed via a tandem propargylation/cycloisomerization reaction of α-oxoketene-N,S-acetals with propargyl alcohols. Notably, in the presence of Bronsted acid p-TSA·H2O, the reaction afforded the hydrolyzed product propargylated-1,3-dicarbonyl compounds, which upon treatment with Cs2CO3 underwent regioselective
通过α-氧杂环丁烯-N,S-乙缩醛与炔丙醇的串联炔丙基化/环异构化反应,已经开发出一种简便高效的InCl 3催化一锅合成高取代的吡咯。值得注意的是,在布朗斯台德酸对-TSA·H 2 O的存在下,反应提供了水解产物炔丙基化的1,3-二羰基化合物,其在用Cs 2 CO 3处理后进行了区域选择性的分子内环化,从而提供了四取代的呋喃衍生物。