This review provides recent advances and insights into photoirradiation reactions of acylsilanes, notablyviakey nucleophilic siloxycarbene intermediates. Nucleophilic addition, insertion reaction, and cyclization are discussed in terms of reaction mechanism and scope.

It is known that 2-quinolones are broadly applicable chemical structures in medicinal and agrochemical research as well as various functional materials. A number of current publications about their synthesis and their applications emphasize the importance of these small molecules. The early synthetic chemistry originated from the same principle of the classical Friedländer and Knorr procedures for the preparation of quinolines. The analogous processes were developed by applying new synthetic tools such as novel catalysts, the microwave irradiation method, etc., whereas recent innovations in new bond forming reactions have allowed for novel strategies to construct the core structures of 2-quinolones beyond the bond disconnections based on two classical reactions. Over the last few decades, some reviews on structure-based, catalyst-based, and bioactivity-based studies have been released. In this focused review, we extensively surveyed recent examples of one-pot reactions, particularly in view of modular approaches. Thus, the contents are categorized as three major sections (two-, three-, and four-component reactions) according to the number of reagents that ultimately compose atoms of the core structures of 2-quinolones. The collected synthetic methods are discussed from the perspectives of strategy, efficiency, selectivity, and reaction mechanism.

In this personal account, we summarize our investigations on the α-alkylation and α-alkenylation reactions of ketones with nonactivated alkenes and alkynes, respectively. The serendipitous discovery of C–H alkylation/alkenylation of cyclic 1,2-diketones provided a proof of concept for a dual activation strategy. Extension to the α-alkylation and α-alkenylation of regular ketones was achieved by using 7-azaindoline as a bifunctional ligand. Subsequently, intramolecular coupling ­between ketones and olefins was achieved with Rh- and Ru-based systems, respectively. Finally, branched-selective α-alkylation was achieved through an Ir-catalyzed enamide-mediated C–H alkylation.1 Introduction2 Serendipitous Discovery of α-Alkylation and α-Alkenylation of 1,2-Diketones through Enamine-Mediated C–H Activation3 Intermolecular Ketone α-Alkylation of Regular Ketones with Nonactivated Olefins4 Intermolecular Ketone α-Alkenylation of Regular Ketones with Nonactivated Alkynes5 Intramolecular Ketone α-Alkylation of Regular Ketones with Nonactivated Olefins6 Branched-Selective α-Alkylation of Regular Ketones with Non­activated Olefins7 Conclusions and Outlook

This review highlights recent advances in maleimide-based annulation and cyclization strategies, offering insights into their synthetic versatility and potential applications in creating structurally diverse aromatics and bioactive heterocycles.