Ring-fused dimethoxybenzimidazole-benzimidazolequinone (DMBBQ): tunable halogenation and quinone formation using NaX/Oxone

Synthesis by radical cyclization and cytotoxicity of highly potent bioreductive alicyclic ring fused [1,2-a]benzimidazolequinones.

The key step in the synthesis of new five, six and seven-membered alicyclic ring [1,2-a]-fused bioreductive benzimidazolequinones was radical cyclisation. Six and seven-membered tributyltin hydride-mediated homolytic aromatic substitutions of nucleophilic N-alkyl radicals onto the benzimidazole-2-position occurred in high yields (63-70 %) when quaternising the pyridine-like 3-N of imidazole wit...

General Methodologies Toward cis-Fused Quinone Sesquiterpenoids. Enantiospecific Synthesis of the epi-Ilimaquinone Core Featuring Sc-Catalyzed Ring Expansion.

A stereocontrolled approach to the cis-decalin framework of clerodane diterpenes and biologically active quinone sesquiterpenes is reported. Starting from an inexpensive optically pure tetrahydroindanone, Birch reductive alkylation builds two new contiguous chiral centers-one of which is quaternary and all-carbon-substituted. Also featured is a highly regioselective diazoalkane-carbonyl homolog...

Tunable Channel Drop Filter using Hexagonal Photonic Crystal Ring Resonators

In this paper, we have proposed a tunable two dimensional (2D) photonic crystal (PhC) channel drop filter (CDF) using ring resonators with suitable quality factor (Q) and transmission efficiency; we investigate parameters which have an effect on resonant wavelength in this CDF, such as dielectric constant of inner, coupling, adjacent and whole rods of the structure. Dropping efficiency at the r...

Tunable Superconducting Split Ring Resonators

Monolithically Integrated Wavelength-Routing Switch Using Tunable Wavelength Converters with Double-Ring-Resonator Tunable Lasers

We present an 8 × 8 wavelength-routing switch (WRS) that monolithically integrates tunable wavelength converters (TWCs) and an 8 × 8 arrayed-waveguide grating. The TWC consists of a double-ringresonator tunable laser (DRR TL) allowing rapid and stable switching and a semiconductor-optical-amplifier-based optical gate. Two different types of dry-etched mirrors form the laser cavity of the DRR TL...