Gold(I)-Catalyzed Cycloisomerization of <i>ortho</i>
-(Propargyloxy)arenemethylenecyclopropanes Controlled by Adjacent Substituents at Aromatic Rings
作者:Wei Fang、Yin Wei、Xiang-Ying Tang、Min Shi
DOI:10.1002/chem.201700600
日期:2017.5.17
Gold(I)‐catalyzed cycloisomerization of ortho‐(propargyloxy)arenemethylenecyclopropanes afforded two different types of products, that is, products of methylenecyclopropane migration and cycloisomerization products of the methylenecyclopropane moiety, controlled jointly by electronic and steric effects of the adjacent substituents. Furthermore, the corresponding cycloisomerization products could be
Thermally Induced Intramolecular Benzannulation of Diazoacetoacetate Enones Tethered with Unactivated Alkynes: Synthesis of Substituted 6H-Benzo[c]chromenes
induced [4+2]-annulation of intermediate vinyl ketenes as the key step. A facile and efficient intramolecular benzannulation strategy for the synthesis of substituted 6H-benzo[c]chromenes from diazoacetoacetate enones tethered with unactivated alkynes has been developed. The reaction proceeds in moderate to good yields under operationally simple conditions with thermally induced [4+2]-annulation of intermediate
抽象的 已开发了一种简便有效的分子内苯环芳构化策略,用于由重氮乙酰乙酸酯烯酮与未活化的炔烃束缚合成取代的6 H-苯并[ c ]色烯。该反应在操作简单的条件下以中等至良好的收率进行,其中关键的步骤是热诱导中间体乙烯基烯酮的[4 + 2]环化。 已开发了一种简便有效的分子内苯环芳构化策略,用于由重氮乙酰乙酸酯烯酮与未活化的炔烃束缚合成取代的6 H-苯并[ c ]色烯。该反应在操作简单的条件下以中等至良好的收率进行,其中关键的步骤是热诱导中间体乙烯基烯酮的[4 + 2]环化。
Regioselective synthesis and structural elucidation of 1,4-disubstituted 1,2,3-triazole derivatives using 1D and 2D NMR spectral techniques
作者:Thelagathoti Hari Babu、B. V. N. Phani Kumar、C. Rajeswari、Paramasivan T. Perumal
through intramolecular Povarovreaction using CuI/Cu(OSO2CF3)2 as a Lewis acid catalyst. The dichromenopyridines synthesis involve two sequential steps, insitu N-heteryl aldimine formation and an intramolecular Aza Diels-Alder[4 + 2] cycloaddition. Furthermore the key intermediate, terminal alkyne tethered Schiff bases subjected to Cu(I) mediated click [3 + 2] cycloaddition with thiazole appended azide
ymé (GBB) reaction for the synthesis of spiro[chromene-imidazo[1,2-a]pyridin]-3′-imine was discovered. The unusual transformation represents the first example of activation and the reaction of the imidazole carbon atom. In this postcondensational modification, KOt-Bu acts as a base, which, after the isomerization of an alkyne moiety to allene, causes the next unique nucleophilic reaction of the imidazole
发现了用于合成螺[色烯-咪唑并[1,2- a ]吡啶]-3'-亚胺的Groebke-Blackburn-Bienaymé(GBB)反应的无过渡金属后修饰。这种不寻常的转变代表了咪唑碳原子活化和反应的第一个例子。在这种后缩合修饰中,KO t -Bu 作为碱,在炔部分异构化为丙二烯后,引起咪唑碳原子的下一个独特亲核反应,从而产生螺环结构。基于DFT计算证实了所提出的反应机理。