Diamides are ubiquitous in chemical constructions of natural molecules with quite a lot of functions. Most of those diamides are accessed by way of acylation of diamines with the corresponding acyl donors, utilizing a defending group or extra quantities of diamines to stop undesirable diacylation reactions. Right here we report a sensible and atom-economical technique to entry monoamide and unsymmetric diamides with diamines and stoichiometric quantities of acyl chlorides – probably the most accessible and extremely reactive acyl donor. Reactivity of diamines may be managed by CO2 as a inexperienced, momentary and traceless defending group for monoacylation reactions, attaining excessive atom efficienty and low environmental issue. We demonstrated the utility of the tactic with a broad substrate scope and a big scale response, and carried out management experiments to elucidate the origin of the excessive selectivity obtained with CO2. We confirmed that ambient CO2 from skinny air affected the selectivity of monoacylation of diamines, implying the pervasive affect of atmospheric CO2 in natural synthesis.