Processing may be easier with reduced cost of goods if that catalyst is not needed. For instance, with the introduction of each additional component come not only increased costs to purchase and qualify the material, but also an increased burden of removing the component and possibly analyzing for the impurity in the product. Of course increased reaction rates and improved impurity profiles with a catalyst can readily compensate for these increased costs. Screening may demonstrate that a catalyst is actually detrimental (for an example of adding a thiol to an epoxide, see Schwartz, A.; Madan, P. B.; Mohacsi, E.; O’Brien, J. P.; Todaro, L. J.; Coffen, D. L. J. Org. Chem. 1992, 57, 851).
