LAUSR

Ketones and aldehydes play central roles in organic synthesis. There are numerous broadly-used reactions that are related to the car-bonyl reactivity, such as Grignard reactions, Wittig reactions, aldol reactions and so on. In addition, the formation of enol triflates is a classic protocol that enables the ketones to be applied in transition-metal catalyzed cross-coupling reactions, in which cases the ke-tones are considered as the precursors of alkenyl electrophiles in the C-C bond forming transformations. In the past decade, a new type of ketone- or aldehyde-based C-C bond forming transformations has emerged. In this type of reactions, the ketones- or alde-hydes are firstly converted to their corresponding N-tosylhydrazones, which are employed as reaction partners in various transition-metal-catalyzed carbene-based cross-coupling reactions. The N-tosylhydrazone-based carbene couplings significantly enhance the potential of ketones and aldehydes in modern organic synthesis. This Perspective aims to give an overview of carbene coupling reac-tions with N-tosylhydrazones from the view point of exploring new potentials of ketones and aldehydes in organic synthesis.