Silver-catalyzed chemoselective annulation of propargyl amines with alkynes for access to pyridines and pyrroles

Isoquinolone Synthesis via Zn(OTf)2-Catalyzed Aerobic Cyclocondensation of 2-(1-Alkynyl)-benzaldehydes with Arylamines

“…Encouraged by the results obtained above, we studied the substrate scope for the formation of isoquinolin-1(2H)-ones using various ortho-alkynylbenzaldehydes and amines bearing different substituents under the conditions of entry 6 in Table 1. As can be seen from Table 2, βaminonaphthalene (2b), para-substituted anilines (para-Me, 2c; parai Pr, 2d; para-Br, 2f), 2-methyl-3methoxyaniline (3e), and 2,4-difluoroaniline (2g) underwent cyclocondensation with 1a affording the Recently, we have been interested in the applications of 2-(1-alkynyl)benzaldehydes in the synthesis of benzo-fused cyclic compounds [28,33,39], air-stable Lewis acids as catalysts in organic transformation [40][41][42][43][44], and the development of synthetic methods for the formation of nitrogen-heterocyclic compounds via alkyne annulations [45][46][47][48][49][50][51][52][53]. Therefore, in continuation of our interests in the application of 2-(1-alkynyl)benzaldehydes, we herein describe a simple and efficient method for the construction of isoquinolone from the cyclocondensation of 2-(1-alkynyl)benzaldehydes with arylamines in the presence of a catalytic amount of Zn(OTf) 2 (Scheme 1, eq.…”

Preliminary Study on Novel Expedient Synthesis of 5-Azaisocoumarins by Transition Metal-Catalyzed Cycloisomerization

“…The structure of 4a was confirmed by comparison of its NMR spectrum with previously reported data ( Table S1 ) (Hellal et al, 2008 ). Recently, many research groups have continuously reported the efficiency of various transition-metal Lewis acid catalysts for alkyne activation in cycloisomerization reaction (Abbiati et al, 2003 ; Yan et al, 2007 ; Cacchi et al, 2008 ; Saito et al, 2009 ; Jiang et al, 2010 ; Fei et al, 2011 ; Mikušek et al, 2016 ; Vessally et al, 2016 ; Nizami and Hua, 2017 ; Sakthivel et al, 2017 ; Gianni et al, 2018 ; Lyubov'N et al, 2018 ; Mancuso et al, 2018 ; Ahn et al, 2019 ). To increase the product yield, cycloisomerization was performed in the presence of various metal catalysts, including Ag(I), Au(I), Cu(I), Cu(II), and In(III).…”

Tandem Reactions of Ynones: via Conjugate Addition of Nitrogen‐, Carbon‐, Oxygen‐, Boron‐, Silicon‐, Phosphorus‐, and Sulfur‐Containing Nucleophiles

“…Over the years, the in situ generated enamines have been applied in different reactions. They functioned in addition reactions as NH‐nucleophiles to alkynes, C‐nucleophiles to alkynes and ketones, as well as electrophiles (Scheme ).…”

“…In 2017, the Hua group developed a chemoselective annulation of propargyl amines with ynones as an access to pyridines 10.2 [Eq. (10‐1)].…”