title: From a chiral switch to a ligand portfolio for asymmetric catalysis.
abstract: This Account is divided into two sections. In the first section, the development of an enantioselective manufacturing process for ( S)-metolachlor, the active ingredient of the grass herbicide Dual Magnum, is described. This is today's largest application of asymmetric catalysis, and the Ir-Xyliphos hydrogenation catalyst achieves unprecedented 2 millions turnovers. The development started in 1982 and ended when the first production batch was run in November 1996. The strategies and approaches used for attaining the elusive goal are described, and the lessons learned are discussed. In the second section, the development and performance of a portfolio of chiral diphosphines for industrial asymmetric applications are described. Central to the portfolio is the idea of modular ligand families, i.e., diphosphines with the same backbone, where steric and electronic properties are easily tuned by the choice of the substituents at the phosphorous atoms.
authors: Solvis AG, Post Office Box, CH-4002 Basel, Switzerland. hans-ulrich.blaser@solvias.com
authors: Hans-Ulrich
authors: HU
authors: Blaser
authors: Benoît
authors: B
authors: Pugin
authors: Felix
authors: F
authors: Spindler
authors: Marc
authors: M
authors: Thommen
mesh_terms: D000081:Acetamides / Q000737:chemistry*; D002384:Catalysis; D008024:Ligands; D010720:Phosphines / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000081:Acetamides; D008024:Ligands; D010720:Phosphines; D010758:Phosphorus; C051786:metolachlor