Laterally non-symmetric aza-cryptands: synthesis, catalysis and derivatization to new receptors

Cryptands where the two bridgehead atoms like N or C or benzene units are connected by three bridges such that the donor atoms about the bridgeheads are different can be called laterally non-symmetric cryptands. These cryptands constitute a class which can be useful in several contemporary areas of research. The present article describes the synthesis of the cryptands and the use of metal cryptates in homogeneous catalysis, in the photochemical splitting of water to generate H-2, in the cleavage of nucleic acids as chemical nucleases. These cryptands can be derivatized to have new receptors which might be useful as well. (C) 2002 Elsevier Science B.V. All rights reserved.