Diels-Alder Reaction Of O-Carboryne With Fulvenes

Carboranes exhibit fascinating features such as spherical geometry and hydrophobic molecular surface, remarkable thermal and chemical stability, which have been found extensive applications in polymers, ceramics, catalysts, and medicals. So it is meaningful to study the fuctionalization of carborane. This thesis mainly focus on the following two chapters:Chapter1introduces the properties of carborane and gives an overview on the recent advances in the field of reactions of carborynes. As a very reactive intermediate, o-carboryne reacts readily with alkenes, dienes, alkynes, aromatics or heteroaromatics in [2+2] and [4+2] cycloaddition as well as ene reaction fashions. On the other hand, o-carboryne can undergo regioselective insertion of sp3α-C-H bond of aliphatic ethers and toluene, as well as sp2ferrocenyl C-H bond to afford a large class of functionalized carboranes. Though the efficiencies are not high, these pioneering reactions promise a new strategy for generating functionalized carboranes that are not ready to access by known methods.Chapter2details the Diels-Alder reaction of o-carboryne with fulvenes, after introducing the recent studies about the Diels-Alder reactions of benzyne with fulvenes. Two different precursors of o-carboryne react smoothly with fulvenes with good yields and are tolerant of different substituents, generating [4+2] adducts which could be transformed to various compounds efficiently without effecting the cage.