Synthesis and Chemistry of Novel Polynitropolycyclic Cage Molecules

摘要

The synthesis and chemistry of novel, strained, saturated polycarbocyclic cage molecules has proved to be a source of fascination for organic chemists. Cage hydrocarbons possess rigid, highly compact structures; such molecules frequently display unusual symmetry properties that render them aesthetically pleasing. Concomitant with their compact nature, carbon-carbon bond angles and bond lengths in carbocyclic cage molecules frequently deviate markedly from the normal values associated with sp3 hybridized carbon atoms. When this occurs, such deviations provide a measure of strain energy that is contained within the cage system. Steric strain can also express itself in a cage system through, e.g., increased negative heat of combustion and increased positive heat of formation relative to that of a corresponding unstrained system. The incorporation of high levels of molecular strain into cage systems confers upon them corresponding levels of thermodynamic instability. Thus, organic chemists who are attracted by the challenge inherent in the synthesis of such highly strained molecules must seek ways to circumvent or otherwise mitigate the deleterious effects of strain in these systems. Partly in response to this need, an important area of organic chemistry, referred to as the synthesis of non-natural products, has emerged and has resulted in the synthesis and study of a large number of novel, highly strained cage molecules. Keywords: Adamantanes; Undecanediones; Cubanes; Undecanes; Dodecanes. Reprints. (aw)