A versatile method for the high-yield synthesis of various tris-, bis-, and mono-annelated benzenes (as well as cyclooctatetraene) is based on the Pd-catalyzed coupling of three (or four) ethylenic units comprised of R,!-dibromoalkenes and R′-alkenyl Grignard reagentssall carried out in a single pot. The particular application to tris(bicyclopentyl)-annelated benzene yields the syn isomer 1s in...

The trinuclear palladium addition to monocyclic unsaturated hydrocarbons was revealed. The trinuclear adduct of [2.2]paracyclophane, cycloheptatriene (CHT), or cyclooctatetraene (COT) was obtained by treatment of the corresponding tripalladium sandwich complexes with 3 equiv. of 1,10-phenanthroline. In the trinuclear adduct of [2.2]paracyclophane or CHT, a Pd2 unit and a Pd1 unit synfacially co...

Cyanine fluorophores exhibit greatly improved photostability when covalently linked to stabilizers, such as cyclooctatetraene (COT), nitrobenzyl alcohol (NBA) or Trolox. However, the mechanism by which photostabilization is mediated has yet to be determined. Here we present spectroscopic evidence that COT, when covalently linked to Cy5, substantially reduces the lifetime of the Cy5 triplet stat...

Despite the tremendous impact of alkene ring-opening metathesis polymerization (ROMP) on the design and the synthesis of polymers and functional materials, examples for the analogous alkyne ROMP remain scarce. This imbalance can be rationalized by the limited availability of commercially available catalysts and the lack of alkyne metathesis monomers. We present here the synthesis and a systemat...

Abstract Noncovalent interactions are an integral part of the modern catalysis toolbox. Although stronger noncovalent such as hydrogen bonding commonly main driving force catalysis, π–π typically provide smaller additional stabilizations, for example, to afford selectivity enhancements. Here, it is shown computationally that pristine graphene flakes may efficiently catalyze skeletal inversions ...

A method is described by which it is possible to determine the high barrier to ring inversion and hindered rotation by neat racemization of optically active compounds when the racemization is caused by ring inversion or hindered rotation. The method is based preparation of sufficiently pure enantiomers, mainly by chromatography on swollen microcrystalline triacetylcellulose (TAC). By this t...