Zn(II)-Catalyzed One-Pot Synthesis of Coumarins from Ynamides and Salicylaldehydes
作者:Huen Ji Yoo、So Won Youn
DOI:10.1021/acs.orglett.9b01181
日期:2019.5.3
A highly efficient and straightforward synthesis of diversely substituted coumarins from ynamides and salicylaldehydes in the presence of Zn(II) catalyst has been developed. The sulfonamide moiety of ynamides was successfully recycled in this process, serving as an effective traceless directing group for high regioselectivity in the bond-forming event. The advantages of this protocol are good functional
A rhodium-catalyzed azide–alkynecycloaddition of internal ynamides is described. The reaction could be performed in a wide range of solvents, including aqueous media, undermildconditions without careful exclusion of air and moisture, giving a variety of 5-amino-triazoles as a single regioisomer. The mechanism of regioselective cycloaddition was rationalized by means of density functional theory
Retention of Stereochemistry in Gold-Catalyzed Formal [4+3] Cycloaddition of Epoxides with Arenynamides
作者:Somnath Narayan Karad、Sabyasachi Bhunia、Rai-Shung Liu
DOI:10.1002/anie.201203723
日期:2012.8.27
Golden opportunity: [4+3] Cycloaddition reactions of arenynamides and epoxides are enabled under gold catalysis and have a broad substrate scope (see scheme; Ms=methanesulfonyl). An SN2‐type front‐side attack of phenyl at the oxiranyl ring is expected to cause the retention of stereochemistry.
千载难逢的机会:[4 + 3]苯甲酰胺和环氧化物的环加成反应在金催化下得以实现,并具有广泛的底物范围(参见方案; Ms =甲磺酰基)。氧杂环戊基环上的一个S N 2型正面进攻性苯环会导致立体化学的保留。
Au(I)‐Catalyzed Annulation of Benzofurazan N‐oxides with Ynamides: From Predicting the Chemo‐Selectivity to the Synthesis of 7‐Nitroindole Derivatives
作者:Changlei Zhu、Luyao Kou、Xiaoguang Bao
DOI:10.1002/cjoc.201900395
日期:2020.1
It could be proposed that gold(I)‐catalyzed reactions of ynamides with benzofurazan N‐oxides might proceed through either O‐attack or N‐attack to afford α‐oxo or α‐imino Au(I)‐carbenoid intermediates. Computational studies were performed to predict that benzofurazan N‐oxides are ready to undergo the chemoselective N‐attack to the Au(I)‐activated ynamides to generate the α‐imino Au(I)‐carbenoid intermediate
Polysubstituted 2-Aminopyrrole Synthesis via Gold-Catalyzed Intermolecular Nitrene Transfer from Vinyl Azide to Ynamide: Reaction Scope and Mechanistic Insights
A gold-catalyzed intermolecular reaction of Vinyl azides and ynamides is described: This process presents an efficient and mild approach to multisubstituted 2-arninopyrroles in good-to-excellent yields. Control experiments were carried out to distinguish the reactivity between vinyl azides and the corresponding 2H-azirines. A plausible reaction mechanism was also proposed according to previous reports and our preliminary mechanistic studies.