Cyanides cyclic amines

Aminoethyl substituents are introduced by reaction of the cyclic amine with tolyl-aziridine, or by cyanomethylation with methanal/cyanide, followed by reduction. Tetrakis[7V-(2-aminoethyl)]-cyclam,... 

Various basic (nucleophilic) initiators can be used to initiate anionic polymerization, including covalent or ionic metal amides, alkoxides, hydroxides, cyanides, phosphines, amines, and organometallic compounds such as butyllithium. The polymerization is initiated by addition of the initiating species to the monomer, typically a vinyl compound with electron-withdrawing moieties. In anionic ROPs, cyclic monomers with electron-deficient carbon atoms such as amides (lactams) and esters (lactones), ethers (oxiranes), or Leuchs anhydrides are used as monomers (Scheme 13). 

An important contribution was recently made by Inoue and co-workers (35) (eq. [4]). Using the chiral cyclic dipeptide cyclo(L-Phe-L-His) these authors obtained a better than 90% e.e. in the reaction of benzaldehyde with cyanide ion. The preparation of the enantiomeric unnatural dipeptide obviously poses far fewer problems than the synthesis of an enantiomeric enzyme. It appears that, at least in principle, optically pure cyanohydrins of the desired configuration are accessible via catalysis by chiral amines or amides. 

A list of more common silver complexing agents includes thiosulfates, thiocyanates, sulfites, cyanides, ammonia and other amines, thiols, thiourea, thioacids, thioethers and alkali halides. Most are not practical as fixing agents because they fail to satisfy all the above criteria. Many find use as silver halide stabilizers (Section 59.2.1.8). These include thiocyanate, thiourea and other thioorganic compounds. These and other complexing agents such as cyclic imides, phosphines and arsines find use in silver halide diffusion transfer processes (Section 59.2.1.6). 

Derivation From a cyclic halogen compound by heating with copper cyanide in the presence of amines. 

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