Oxidative Coupling/Cyclization Reactions Involving Olefins

In organometallic chemistry, transition metal catalyzed organic reactions provide more efficient, high selective bond-breaking/formation methods for organic chemistry, and provide numerous methods for efficient and selective organic synthesis. They have highly improved the technology of organic synthesis and among them, the olefin involved transition metal catalyzed coupling reactions are one of the most effective methods for direct construction of C=C double bond contained componds and cyclic compounds. Meanwhile, the transition-metal free coupling reactions have also drove many attentions in recent years. With the development of concepts in green, sustainable-chemistry, development of new green and efficient coupling reactions have been a priority for chemists.This thesis firstly described the achievements of organometallic chemistry and the surveys of transition-metal-catalyzed/promoted reactions. And specifically focused on the development status of C=C bond invovled coupling reactions. Then this thesis described the oxidative β-arylation reaction of electron rich olefins, oxidative alkynylation/cyclization reaction of Csp3-H bond and transition-metal-free oxidative cyclization of olefins with quinones. The follows are detailed contents:(1) The first palladium catalyzed oxidative β-arylation of electric rich olefins with aryl boric acids was discribed. With palladium acetate as catalyst, p-benzoquinone as oxidant, a series of substituted aryl boric acids could well coupled with vinyl acetates to formation of β-arylation vinyl acetates. And by adjusting the reaction conditions,1,2-diaryl ethylene could be formed from vinyl acetate and aryl boric acid as well.(2) The first palladium catalyzed aerobic oxidative Csp3-H alkynylation/cyclization reactions was developed. With palladium acetate as catalyst,4-n-butyl bromide as additive and oxygen molecules as oxidant, an intramolecular alkynylation/cyclization reaction could occur in a series of substituted imines, which formed from acetophenones and allylamine, under mild conditions and polysubstituted pyrrole compounds isomerization could be obtained. By using the methyl substituted allylamine the multiple substituted cyclopropane compounds could be synthesized as well under similar conditions (3) The first transition-metal-free oxidative cyclization reaction of olefins with quinones was developed. With Cu(OTf)2as catalyst precursor or HOTf as catalyst, quinones as oxidant, a various of substituted styrene could cyclized with benzoquinone and naphthoquinone to formation of tetrahydrobenzodifuran compounds. A synergetic oxidative cyclization/[3+2]cyclization mechanism was proposed based on the experimental results. A variety of substituents were found to be tolerated in this protocol including halogen groups. And asymmetric tetrahydrobenzodifuran could also be synthesized from two different olefins in one pot.