Norbornene

About: Norbornene is a research topic. Over the lifetime, 5628 publications have been published within this topic receiving 104495 citations. The topic is also known as: norbornylene & norcamphene.

Cationic gold(III) alkyl complexes: generation, trapping, and insertion of norbornene.

Abstract: Migratory insertion of alkenes into gold–carbon bonds, a fundamental yet unprecedented organometallic transformation, has been investigated from a discrete (P,C) cyclometalated gold(III) dimethyl complex. Methide abstraction by B(C6F5)3 is shown to generate a highly reactive cationic AuIII complex that evolves spontaneously by C6F5 transfer from boron. In the presence of norbornene, migratory insertion into the AuC bond proceeds readily. The resulting norbornyl complex is efficiently trapped with pyridines or chloride to give stable four-coordinate adducts.

Highly Tactic Cyclic Polynorbornene: Stereoselective Ring Expansion Metathesis Polymerization of Norbornene Catalyzed by a New Tethered Tungsten-Alkylidene Catalyst

Abstract: The tungsten alkylidyne [tBuOCO]W≡C(tBu) (THF)2 (1) reacts with CO2, leading to complete cleavage of one C═O bond, followed by migratory insertion to generate the tungsten-oxo alkylidene 2. Complex 2 is the first catalyst to polymerize norbornene via ring expansion metathesis polymerization to yield highly cis-syndiotactic cyclic polynorbornene.

Fe(OTf)(3)-catalyzed addition of sp C-H bonds to olefins.

Abstract: We have developed a novel acid-catalyzed addition of acetylenes to olefins in the presence of catalytic triflic acid or its metal salts. Among the various triflates, the catalytic activities depend on the cation and decrease in the order Fe3+ > Al3+ ≫ H+, In3+, Sc3+ ≫ Cu2+, Ag+. In general, “hard” acids gave higher yields than “soft” acids such as copper and silver triflates. Among relatively hard acids, Fe(OTf)3 was the best catalyst, which is also the case for ester formation from carboxylic acids and olefins. Our procedure is unique and attractive for the following reasons: (i) The reaction proceeds even for isolated C═C double bonds, as in norbornene. (ii) The reaction is promoted by acid catalysts and does not include an oxidation−reduction cycle for transition metals. (iii) Moreover, these catalysts are inexpensive, abundant, and less toxic than precious-metal-based catalysts. The reaction proceeds even under air and does not require precious metals.