1,2‐Aminofunctionalization Reactions of Pyridino‐Alkynes via Carbophilic Activation

Abstract

Transition metal-catalyzed 1,2-difunctionalization reactions of alkynes have emerged as a powerful tool to forge carbon-carbon and carbon-heteroatom bonds for the rapid synthesis of polyfunctionalized molecular scaffolds. In this regard, our group has persistently been developing transition metal-mediated 1,2-aminofunctionalization reactions of alkynes through a rationally designed pyridino-alkyne core by utilizing the carbophilic activation strategy. In this account, we present an array of such 1,2-aminofunctionalization reactions which have been successfully executed on this core to afford important polycyclic frameworks such as functionalized quinalizinones, pyridinium oxazole dyads (PODs), N-doped polycyclic aromatic hydrocarbons (PAHs), N-doped spiro-PAHs. Additionally, the synthesis of phosphine ligated gold complexes bearing pyrido-isoquinoline scaffold from the pyridino-alkynes will be discussed briefly.

AIEgens Based on Anion‐π+ Interactions: Design, Synthesis, Photophysical Properties, and Their Applications in Material Science and Biology

“…One of the authors of the manuscript, have earlier reported a series of reactions on the metal‐catalysed cyclization reactions of pyridino‐alkynes [14] to access new fluorophores [15] . Inspired by these results, we recently developed a library of AIEgens through an endo ‐selective silver‐mediated cyclization of pyridino‐alkynes Py‐Alk to access benzo[a]quinolizinium‐base dionic AIEgens BQ (Scheme 3).…”

“…One of the authors of the manuscript, have earlier reported a series of reactions on the metal-catalysed cyclization reactions of pyridino-alkynes [14] to access new fluorophores. [15] Inspired by Scheme 1. AIEgens through anion-π + interaction: An initial report.…”

Ligand-Enabled Sustainable Gold Catalysis

“…There have been reviews that focus on optimization studies and reactivities in gold catalysis; , however, a thematic review on the development of homogeneous sustainable gold catalysis at a ppm level has remained highly sporadic in the literature. , In light of our long-standing interest in the development of homogeneous gold catalysis, − herein, we would like to present a comprehensive perspective summarizing all the reports that employ catalyst loadings ≤ 0.1 mol %. A special emphasis on the roles of electronic and steric effects of ligands to achieve high turnover numbers (TONs) and turnover frequencies (TOFs) are given for a better understanding for the readers.…”

Interplay of Anion‐π+ and π+‐π+ Interactions in Novel Pyrido[2,1‐a]isoquinolinium‐Based AIEgens ‐ Substituent‐ and Counterion‐Dependent Fluorescence Modulation and Applications in Live Cell Mitochondrial Imaging**

“…However, such reports remain highly sporadic in literature. [24][25][26] Inspired by our ongoing interest in catalytic carbophilic activation and especially developing metal-catalyzed cyclization reactions of pyridino-alkynes to access fluorophores; [30][31][32][33][34] herein, we disclose a method to access a library of AIEgens based on the interplay of anion-π + , π + -π + and other non-covalent interactions. A significant impact of substituents, their position, and the nature of counterions, was found to be important in modulating their photophysical properties.…”