It has been shown that compounds containing the p-N,N,-dialkylaminobenzylidene cyanoacetate motif can serve as fluorescent non-mechanical viscosity sensors. These compounds, referred to as molecular rotors, belong to a class of fluorescent probes that are known to form twisted intramolecular charge-transfer complexes in the excited state. In this study we present the synthesis and spectroscopic characterization of these compounds as viscosity sensors. The effects of the molecular structure and electronic density of these rotors to the emission wavelength, fluorescence intensity and viscosity sensitivity are discussed.

Explorations into a series of different approaches for 9‐membered carbocycle formation have afforded the first reported example of a 9‐exo‐dig ring closure via a AuIII‐promoted reaction between an alkyne and an aryl ring as well as several additional, unique Friedel–Crafts‐type cyclizations. Analyses of the factors leading to the success of these transformations are provided, with the application of one of the developed 9‐membered ring closures affording an efficient and scalable synthesis of the bioactive resveratrol trimer caraphenol A. That synthesis proceeded with an average yield of 89 % per step (7.8 % overall yield) and has provided access to more than 600 mg of the target molecule.

IDSI to the Rescue Use of a carefully designed cascade process empowered by the unique iodonium-reagent IDSI [(Et2SI)2Cl•SbCl6] provided the means to construct the entire [3.2.2]-bicyclic core of both targets in a single, stereocontrolled operation. Use of strain energies assisted in the completion of the natural products, with the overall strategy proving applicable as well to the preparation of a number of unique [3.2.1]-dimeric and highly strained resveratrol-based compounds.

Ein Reagens namens IDSI, [(Et2SI)2Cl⋅ SbCl6], löst eine sorgsam entworfene Reaktionskaskade aus, die den zentralen [3.2.2]Bicyclus beider Zielverbindungen, 1 und 2, in einer einzigen stereokontrollierten Operation liefert. Auf dem weiteren Weg zu den Naturstoffen wurden Spannungsenergien genutzt.

Although interest in cyclotriveratrylene and its analogues has been significant, limitations in the ability to adjust its structure fully have hampered studies into their complete range of properties. A unique strategy to synthesize a previously unobtainable cyclotriveratrylene analogue and a procedure which adjusts the inner methylene bridges of that material to a triketone is reported. A second triketone synthesis and computational studies indicate the parameters needed for success.