Synthesis of 2‐Alkenyl‐4
<i>H</i>
‐3,1‐Benzoxazin‐4‐Ones through HFIP‐Mediated Decarboxylative [4+2]‐Annulation of Isatoic Anhydrides with Cyclopropenones under Silver Catalysis
作者:Mengqi Yang、Jixin Wang、Weiwei Lv、Dan Ba、Guolin Cheng、Lianhui Wang
DOI:10.1002/adsc.202100489
日期:2021.8.13
We herein describes an HFIP-mediated [4+2]-cycloaddition reaction from simple and easily available isatoic anhydrides and cyclopropenones under silver catalysis. This transformation involves the tandem decarboxylative esterification, intermolecular addition, intramolecular substitution, small ring opening and isomerization processes, which allows the rapid assembly of versatile 2-diarylalkenyl-4H-3
我们在此描述了 HFIP 介导的 [4+2]-环加成反应,该反应在银催化下由简单易得的靛红酸酐和环丙烯酮进行。这种转化涉及串联脱羧酯化、分子间加成、分子内取代、小开环和异构化过程,这使得多功能 2-diarylalkenyl-4 H -3,1-benzoxazin-4-ones的快速组装成为可能。
Silver-catalyzed ring-opening [3+2] annulation of cyclopropenones with amides
作者:Takanori Matsuda、Yuki Tabata、Hirotsugu Suzuki
DOI:10.1039/c8nj04579h
日期:——
A ring-opening [3+2] annulation reaction between cyclopropenones and amides was developed to produce 5-amino-2-furanones. Insertion of the carbonyl group of an amide to the C–C single bond of a cyclopropenone occurred efficiently in the presence of a catalytic amount of silver(I) triflate.
Ag2O-promoted ring-opening reactions of cyclopropenones with oximes is disclosed in this work, providing a direct route to 1,3-oxazinones. This method highlights a new reactivity of cyclopropenones which undergo 1,4-addition with oximes followed by β-carbon elimination to in situ generate a α-carbonyl ketene intermediate.
Transition-metal-catalyzed annulation reactions of difluorocyclopropenes with alkynes or N,N-dialkylformamides and homocoupling reaction of difluorocyclopropenes have been realized under mild conditions. These reactions tolerate a range of functional groups, furnishing the corresponding products in moderate to good yields. In addition, isotope labeling experiment shows that water indeed involves in