C(CO)-alkyl bonds are ubiquitous in a variety of organic molecules,and their selective activation and functionalization are important for the reconstruction of simple ketones into valuable building blocks.However,due to the thermodynamic and kinetic stability,the cleavage and transformation of the unstrained C(CO)-alkyl bonds remain a significant challenge.Herein,we report a novel silver-catalyzed scission of the unstrained C(CO)-alkyl bond of ketones by reacting with N-isocyanoiminotriphenyl-phosphorane(NI1TP)under mild conditions.This method could transform a variety of unstrained ketones into iminopho-sphoranes and nitriles in high yields.Experimental and computational studies disclosed the reaction proceeded through an unprecedented[3+2]/retro-[3+2]cycloaddition mechanism.