Storage of photovoltaic and wind electricity in batteries could solve the mismatch problem between the intermittent supply of these renewable resources and variable demand. Flow batteries permit more economical long-duration discharge than solid-electrode batteries by using liquid electrolytes stored outside of the battery. We report an alkaline flow battery based on redox-active organic molecu...

Quinone methides are fundamental intermediates for a wide range of reactions in which catalyst stereocontrol is often achieved by hydrogen bonding. Herein, we describe the feasibility an intramolecular Friedel–Crafts 6π electrocyclization through ortho-quinone methide iminiums stereocontrolled contact ion pair. A disulfonimide activates racemic trichloroacetimidate substrates and imparts cycliz...

Visible-light triggered quinone trimethyl locks are reported as a general design for long-wavelength photoremovable protecting groups for alcohols and amines. Intramolecular photoreduction unmasks a reactive phenol that undergoes fast lactonization to release alcohols and amines. Model substrates are released in quantitative yield along with well-defined, colorless hydroquinone byproducts. Subs...

The main structural features of the cytochrome b6f complex, solved to 3.0-3.1 A (1 A = 10(-10) m) in the cyanobacterium Mastigocladus laminosus and the green alga Chlamydomonas reinhardtii are discussed. The discussion is focused on the binding sites of plastoquinone and quinone analogue inhibitors discerned in the structure. These sites mark the pathway(s) of quinone translocation across the c...

Some representative quinones, viz. one naphthoquinone (plumbagin) and five anthraquinones (alizarin, purpurin, chrysazin, emodin, and anthrarufin), were subjected to electrocoagulation. It was found that the rate and extent of coagulation of these compounds appears to correlate with the number and relative position of their phenolic substituent groups, and that all of the coagulated quinones co...

Every Bacillus species so far examined contains menaquinone as the sole quinone. In contrast, the alkalophilic Bacillus alcalophilus has been reported to be unusual in containing ubiquinone rather than menaquinone. In this communication, we demonstrate that B. alcalophilus, like all the other bacilli, contains menaquinone as the only quinone.

A new method for imine synthesis by way of quinone-catalyzed oxidative deformylation of 1,2-amino alcohols is reported. A wide range of readily accessible amino alcohols and primary amines can be reacted to provide N-protected imine products. The methodology presented provides a novel organocatalytic approach for imine synthesis and demonstrates the synthetic versatility of quinone-catalyzed ox...

Herein, we describe the first catalytic asymmetric intramolecular [4+2] cycloaddition of in situ generated ortho-quinone methides. In the presence of a confined chiral imidodiphosphoric acid catalyst, various salicylaldehydes react with dienyl alcohols to give transient ortho-quinone methide intermediates, which undergo an intramolecular [4+2] cycloaddition to provide highly functionalized fura...

[reaction: see text] A stereoselective synthesis of (-)-ilimaquinone (4) is presented. The synthetic strategy is based on a novel radical decarboxylation and quinone addition methodology that produces quinone 7 from reaction of thiohydroxamic acid derivative 8 with benzoquinone (9). Final functionalization of 7 to ilimaquinone (4) is achieved by exploring the electronic effects of the residual ...