Catalysts from the Chiral Pool

3) Ready availability A good organocatalyst can be prepared from natural products in a minimum number of steps, keeping down the environmental impact of its synthesis 

4) User-friendliness With few exceptions, organocatalysts do not suffer from sensitivity to oxidation and hydrolysis. This makes them easy to work with, without the inert atmospheres required for many metal-catalyzed reactions 

5) Metal-free catalysis Organocatalysis removes concerns over whether a pharmaceutical or agrochemical might be contaminated with metal impurities from the catalyst. 

However, it does not necessarily follow that a natural molecule will have a favorable environmental profile [40b]. Many of the most toxic molecules known to science come from Nature, and natural molecules may not break down effectively in the absence of the organisms or conditions required for their biodegradation. 

Alkaloids, especially those from the Cinchona family, have proven popular as lead structures in the design of organocatalysts because they contain amino groups, which 

---

One of the fundamental operations in organic synthesis remains the stereoselective reduction of carbonyl groups1241. In a process related to that reported by Hosomi et u/.[25], using hydrosilanes as the stoichiometric oxidant and amino acid anions as the catalytic source of chirality, a variety of ketones were reduced in good to excellent yield and with good stereoselectivity1261. This process reduces the amount of chiral catalyst needed and utilizes catalysts from the chiral pool that can be used directly in their commercially available form. 

---