The key feature of the SMH mechanism is Ag+ strong interact with C≡C bond of siloxy-alkynes and activate R3Si group into silylium ion SiR3+ through p-π conjugate effect. SN2 nucleophilic attack of 2 at silicon atom of siloxy-alkyne is the initial step of the SMH mechanism. We divide the SMH mechanism into two parts for convenient, the first part (part I) is Ag+ induced SiR3+ and proton exchange between siloxy-alkyne 1 and amide 2, which lead to AgNTf2 coordinated ketene INT3A and silyl-imine INT3B; the second part (part II) is nucleophilic addition between INT3A and INT3B to form INT4A, following with a silylium migration afford final product Z-3 (Scheme 2). By its nature, this is an Ag+ and SiR3+ exchange process, which have emerged as useful catalytic method, especially for unique transformations hardly accessible to Lewis acid .