Part I. Organic stereochemistry at a pseudo-octahedral center. Part II. Molecular surgery of fullerene carbon(60).

摘要

Chapter I gives a general review on the regiochemistry of multiple addition; to fullerene C₆₀. A complete control over the addend permutation at pseudo-octahedral locations on C₆₀ is introduced as the primary target of this work. In addition, a molecular surgery approach toward a non-classical fullerene C_2v-C₆₂ is proposed.; Chapter II presents the design and preliminary test of a “mer-3+3” sequential regiocontrol strategy. The preparation of the key precursor, a tethered trans-1 bis-Diels-Alder adduct of C₆₀, and its subsequent highly selective functionalization to the first “mer-A3+B3” hexakisadduct is described.; Chapter III details a comprehensive study of the regioselectivity of every intermediate pseudo-octahedral addition pattern of C₆₀. By judiciously selecting the addition sequence and the type of addends, a complete series of seven isomeric “A2+B2+C2” hexakisadducts can be synthesized in a facile, parallel manner.; Chapter IV describes the final accomplishment of the complete control over addend permutation at pseudo-octahedral sites of C ₆₀, as demonstrated by the efficient preparation of a pair of fully permutated and fully differentiated edge-to-face isomers. A refined procedure of the initial “mer-3+3” regiocontrol strategy, which makes exquisite utility of both steric and electronic effects, is essential to overcome a significant regioselection obstacle at the late stage of multifunctionalization.; Chapter V reports the formation of C₆₂ in gas phase from its synthetic precursor. Stable C₆₂ derivatives are obtained in a designed cascade reaction between C₆₀ and tetrazines. The expected 4-membered ring within the fullerene framework is confirmed in the preliminary X-ray structure of such compounds.; Chapter VI describes a systematic investigation of a photochemically promoted tandem [4+4]/retro[2+2+2] rearrangement reaction. A novel strategy for the regioselective multiple application of this reaction is also described.