Disclosed are metal-bound tetracarbene catalysts, such as iron based aziridination catalyst, having the formula: wherein X is a group 6, 7, 8, 9, or 10 metal and wherein Z is a hydrogen, alkyl, aryl or organic group, wherein the alkyl, aryl or organic group is optionally are independently substituted. In a specific example, a metal-bound tetracarbene catalyst has the formula: Also disclosed are methods of making (synthesizing), transmetallation reagents, these agents, metal-bound tetracarbene catalysts, and a method of catalytic alkene aziridination, using the disclosed metal-bound tetracarbene catalysts.