Thermal [2 + 2]-cycloaddition between silylalkynes and allenylphenols followed by the nucleophilic addition of water: metal-free and economical synthesis of arylcyclobutenals
作者:Shohei Ohno、Ramon Francisco Avena、Hiroshi Aoyama、Hiromichi Fujioka、Mitsuhiro Arisawa
DOI:10.1039/c9gc04184b
日期:——
A novel thermal [2 + 2]-cycloaddition between silylalkynes and allenylphenols to form a cyclobutachromene intermediate, followed by the nucleophilic addition of water to yield functionalized arylcyclobutenals.
Pauson–Khand reactions of functionalized allenes with different alkynes give cyclopentenones with generally high regio- and stereoselectivities. The allenes react through their external double bonds, giving cyclopentenones with exocyclic double bond at their β positions and predominantly with E stereochemistry. Some intramolecularreactions with allenynes connected through aromatic rings are described
具有不同炔烃的官能化丙二烯的 Pauson-Khand 反应产生具有通常高区域选择性和立体选择性的环戊烯酮。丙二烯通过它们的外部双键反应,得到在其 β 位置具有环外双键的环戊烯酮,主要是 E 立体化学。描述了通过芳环连接的丙炔的一些分子内反应。这些以中等至良好的产率得到相应的杂环。
One‐Pot Synthesis of 1,2,3‐Triazolo Polycyclic Systems via Copper‐Catalyzed/TsOH‐Promoted Tandem Annulation of 1,6‐Allenynes with Organic Azides
A copper-catalyzed/TsOH-promoted one-pot tandem annulation of 1,6-allenynes with organicazides was reported, providing N-allyl 1,2,3-triazole-fused structures in moderate to excellent yields under mild reaction conditions. Moreover, the late-stage diversification of the N-allyl products can be realized by chemoselectively reducing to the N-alkyl counterparts.