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Using 2-(2-aminophenyl)quinazolin-4(3 H)-one and 2-(2-phenylethynyl)benzaldehyde as the reactants, silver triflate (AgOTf) was proved to be an efficient catalyst to promote not only quinazoline cyclization, but also the intramolecular hydroamination of alkyne for the synthesis of 6-aryl-17 H ,18a H -isoquinolino[2,1- a ]quinazolino[3,2- c ]quinazolin-17-one derivatives in high yields. [ABSTRACT FROM AUTHOR]

The selective modification of α-amino acids and peptides constitutes a pivotal arena for accessing new peptide-based materials and therapeutics. In recent years, visible light photoredox catalysis has appeared as a powerful platform for the activation of small molecules via single-electron transfer events, allowing previously inaccessible reaction pathways to be explored. This review outlines the recent advances, mechanistic underpinnings, and opportunities of applying photoredox catalysis to the expansion of the synthetic repertoire for the modification of specific amino acid residues. 1 Introduction 2 Visible-Light-Mediated Functionalization of α-Amino Acids 2.1 Decarboxylative Functionalization Involving Redox-Active Esters 2.2 Direct Decarboxylative Coupling Strategies 2.3 Hypervalent Iodine Reagents 2.4 Dual Photoredox and Transition-Metal Catalysis 2.5 Amination and Deamination Strategies 3 Photoinduced Peptide Diversification 3.1 Gese-Type Bioconjugation Methods 3.2 Peptide Macrocyclization through Photoredox Catalysis 3.3 Biomolecule Conjugation through Arylation 3.4 C–H Functionalization Manifolds 4 Conclusions and Outlook [ABSTRACT FROM AUTHOR]

A double Ullmann coupling reaction successfully takes place between 4,5-diaryl-2-(2-bromophenyl)-1 H -imidazoles and 2-bromophenols in the presence of Cs2 CO3. This procedure is catalyzed by copper(I) iodide and o -phenanthroline and provides an efficient method for the synthesis of dibenzo[ b , f ]imidazo[1,2- d ][1,4]oxazepine derivatives in good yields. [ABSTRACT FROM AUTHOR]