Urotropine Isomer (1,4,6,10-Tetraazaadamantane): Synthesis, Structure, and Chemistry
摘要:
The first synthesis of 1,4,6,10-tetraazaadamantane, the C-3v-symmetrical structural isomer of urotropine (1,3,5,7-tetraazaadamantane), and a series of its derivatives is reported. X-ray and quantum-chemical studies revealed remarkable distinctions in structures of urotropine and "isourotropine" cations, probably arising from different types of hyperconjugation between lone electron pairs of nitrogen atoms and sigma(C-N)* orbitals in these heterocage systems. Since substitution at bridge and bridgehead nitrogen atoms can be easily introduced, 1,4,6,10-tetraazaadamantane may be considered as a new rigid multivalent (3 + 1) scaffold for the design of functional molecules and materials.
Unusual Intramolecular Cyclization of Tris(β-oximinoalkyl)amines. The First Synthesis of 1,4,6,10-Tetraazaadamantanes
摘要:
An unusual intramolecular cyclization of tris(beta-oximinoalkyl)amines 1 into 4,6,10-trihydroxy-1,4,6,10-tetraazaadamantanes 2 was discovered. Compounds 2 are related to a previously unknown type of heteroadamantanes that contain the cage Isomeric to urotropin. A simple three-step synthesis of tetraazaadamantanes 2 and their N-substituted derivatives 3 and 4 from ammonia and aliphatic nitro compounds via the intermediacy of available tris-oximes 1 was developed.