Catalytic carbene/alkyne metathesis (CAM): a versatile strategy for alkyne bifunctionalization

Metal carbene, as a reactive intermediate, has shown versatile applications in modern organic synthesis. One of the priorities in this area is exploration of stable carbene precursors with structural diversity. Catalytic carbene/alkyne metathesis (CAM) with readily available and stable materials, such as α-carbonyl diazo compounds, provides an effective approach for the in situ generation of vinyl carbene intermediates, which is difficult to directly access with other carbene precursors. Thus, novel cascade transformations involving the CAM process for the straightforward construction of polycyclic frameworks have been well documented. Challenges including side reaction control and asymmetric catalysis in this area need to be explored. This review will summarize the recent advances in this field and be divided by the type of the terminating carbene reactions.