Computation has guided the design of conformationally-strained dioxolane-fused trans-cyclooctene (d-TCO) derivatives that display excellent reactivity in the tetrazine ligation. A water soluble derivative of 3,6-dipyridyl-s-tetrazine reacts with d-TCO with a second order rate k2 366,000 (+/- 15,000) M-1s-1 at 25 °C in pure water. Furthermore, d-TCO derivatives can be prepared easily, are access...

High-valent iron oxidants are known to be the catalytically active species in heme enzymes, and the last decade has seen similar developments in non-heme-iron biomimetics and biochemistry. 2] Extensive reactivity studies, structural, spectroscopic, and computational work have established {FeOOH} and {Fe=O} as relevant intermediates in catalytic oxygenation processes. The species {Fe=O} has also...

The FeII complexes of two isomeric pentadentate bispidine ligands in the presence of H2O2 are catalytically active for the epoxidation and 1,2-dihydroxylation of cyclooctene (bispidine = 3,7-diazabicyclo[3.3.1]nonane; the two isomeric pentadentate bispidine ligands discussed here have two tertiary amine and three pyridine donors). The published spectroscopic and mechanistic data, which include ...

Enantiodifferentiating geometrical photoisomerizations of (Z)-cyclooctene and (Z,Z)-1,3-cyclooctadiene were performed by using the pyromellitate-linked cyclodextrin network polymer, termed "cyclodextrin nanosponge (CDNS)", as a supramolecular sensitizing host. The photochirogenic behavior of the nanosponges incorporating β- or γ-cyclodextrin was significantly different from that reported for th...

The efficient synthesis of two new stereoisomeric 3-aminocyclooctanetriols and their halocyclitol derivatives starting from cis,cis -1,3-cyclooctadiene are reported. Reduction cyclooctene endoperoxide, obtained by photooxygenation -1,3-cyclooctadiene, with zinc yielded a diol followed acetylation the hydroxy group, which gave dioldiacetate OsO 4 /NMO oxidation. cyclooctane prepared was converte...

There is considerable interest in the use of bioorthogonal covalent chemistry, such as “click” reactions, to label small molecules located on live or fixed cells. Such labeling has been used for the visualization of glycans, activity-based protein profiling, the site-specific tagging of proteins, the detection of DNA and RNA synthesis, investigation of the fate of small molecules in plants, and...

The catalysis by S, 1 0, IS,20-tetrakis(pentafluorophenyl)-21H,23H-porphyrin iron(III) chloride (F20 TPPFeCl) of alkene epoxidation by H20 2 has been investigated. Extensive catalyst decomposition was observed during the reaction. A kinetics and product yield analysis has shown that this decomposition does not occur via either the oxoperferryl intermediate (F 20 TPP·+)F e =0 or the oxoferryl in...

A new class of sterically hindered dendrimer-metalloporphyrins was synthesized for use as shape-selective oxidation catalysts. A series of oxidatively robust poly(phenylesters) dendrimers were prepared through a convergent synthesis. Monodendrons were appended to the meta-positions of the 5,10,15,20-tetrakis(3′,5′-hydroxyphenyl)porphinatomanganese(III) chloride to obtain a sterically protected ...