Fundamentals of asymmetric catalysis

Conducting organic synthesis in asymmetric mode – that is making one mirror image form of a chiral molecule in preference over the other – is an art that has been known for more years than commonly known. At the brink of the hundredth anniversary celebrating the seminal achievement which for the first time enabled stereoselective preparation of compounds by means of chemocatalysis, albeit initial attempts in this regard were made already in the late nineteenth century, the time is perfect to review and summarize major milestones. From a rather sluggish start where the area attracted scattered interest mainly by a limited group of academics, the potential to develop the associated technology for large scale applications gained momentum in the 1950s and 1960s. This paradigm shift raised the profile of asymmetric catalysis tremendously, which paved the way to a considerably enhanced industrial awareness and attention to this opportunity. Thus, from the early 1970s and onwards, the development has largely been conducted in parallel with major contributions from both academia and industry – notably applying transition metals such as Pd, Ru, Rh, Ir, Mn, and Ti in combination with chiral ligands as catalysts. In particular, the latter party has pioneered the scale up of asymmetric processes to higher volumes on both pilot plant and commercial scale, whereas the former has primarily focused on basic research and design of novel methods and catalytic systems. Today, we can enjoy a number of successful cases in operation, for example, the manufacture of pharmaceuticals, fragrances, and pesticides, based on ingenuously refined catalytic principles that enable efficient production of the whole range from kg amounts to multi-ton quantities with excellent stereochemical purity.