Polycyclic ring structures are pervasive unit in nature products and pharmaceutical molecules.Although methods have been developed for the effective construction of the ring systems with various frameworks,the synthetic potential of development efficient cascade reactions access to these structures is contiuning to become intensive.Herein,we disclosed a new type of metal carbene cascade reaction of alkynyl tethered diazoacetates,which proceeds through initial metal carbene formation via catalytic diazo decomposition,carbene/alkyne metathesis,and terminated with typical metal carbene reactions.The proposed strategy is a versatile and direct access to the polycyclic ring structures from the alkyne tethered diazo compounds by simply switching the built in linkers(purple)and terminating groups(green),and chiral polycyclic rings with structure diversity,including various heterocycles,could be envisioned via this methodology.