Activation of Carbon–Hydrogen Bonds via 1,2-RH-Addition/-Elimination to Early Transition Metal Imides

A tutorial addressing the activation of carbon–hydrogen bonds via the 1,2-RH-addition to high oxidation state, early metal X n M═NR complexes is described. Details regarding the reverse 1,2-RH-elimination from X n (R′)M–NHR, are also presented. The overall process is discussed as follows: (1) electrophilicity and electronics; (2) general mechanism; (3) kinetics of 1,2-RH-elimination; (4) periodic trends; (5) alkane complexes; (6) kinetic isotope effects (KIEs); (7) RH activation selectivities; and (8) future directions.