Crown Ethers · Cryptands

During the last two decades, the concept of molecular recognition has become to play a central role in chemistry. So-called host-guest chemistry employing crown ethers, cryptands and related hosts has contributed to the development of this concept. This review deals with molecular recognition by these hosts for 1) cations, 2) anions, 3) neutral molecules, and 4) chiral guests. And recent studies on their application to asymmetric synthesis and enzyme modeling are briefly summarized.