To determine the degree of iteroselectivity, we introduce the concept of iteromeric excess ite by analogy to enantiomeric and diastereomeric excesses. Since the ratio of each iteromer can be different under a normal distribution, we define the ite based on the difference between the ratio of the iteromer i obtained experimentally rexp (that can be assimilated to the yield) and the normal ratio rnormal that both range from 0 to 1 (equation 1). The ite ranges from 0 to 100% for positive iteroselectivity, and from -∞ to 0 for negative iteroselectivity. Conveniently, in presence of an excess of reagent, rnormal equals 0 for any product other than the per-functionalized product and, therefore, the ite equals the yield (rexp).