Catalyst development statistical approaches

Franklin, N.L., Pinchbeck, P.H., and Popper, F. (1956), A Statistical Approach to Catalyst Development Part I The Effect of Process Variables on the Vapour Phase Oxidation of Naphthalene, Trans. Instn. Chem. Engrs, 34, 280-293. 

Statistical process control is being implemented by catalyst manufacturers to detect and eliminate, if possible, causes of variations in quality. As many departments, such as operating, technical, purchasing, and R D, become involved in the pursuit of quality, a unified approach toward the implementation of total quality is being developed through an accreditation procedure for catalyst suppliers. 

The cross-benzoin reaction between two different aldehydes typically produces a statistical mixture of products, although in some cases a single thermodynamic product predominates. A number of approaches have been developed to circumvent the limitations of the cross-benzoin reaction. In one approach, a thiamine diphosphate-dependent enzyme is used to promote a selective cross-benzoin reaction, often with high levels of asymmetric induction. In other approaches, one aldehyde coupling partner is replaced with a selective acyl donor. Cyanohydrin derivatives have proven to be ideal preformed acyl donors, and their use constitutes a stepwise benzoin condensation that is stoichiometric in cyanide. The discovery that acylsilanes can serve as cyanohydrin precursors has led to the development of a highly selective cyanide-catalyzed cross-benzoin condensation. By employing a chiral metallophosphite catalyst instead of potassium cyanide, good to excellent levels of asymmetric induction are possible. 

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