Macromolecular Design Strategies for Preventing Active-Material Crossover in Non-Aqueous All-Organic Redox-Flow Batteries.

Intermittent energy sources, including solar and wind, require scalable, low-cost, multi-hour energy storage solutions in order to be effectively incorporated into the grid. All-Organic non-aqueous redox-flow batteries offer a solution, but suffer from rapid capacity fade and low Coulombic efficiency due to the high permeability of redox-active species across the battery's membrane. Here we show that active-species crossover is arrested by scaling the membrane's pore size to molecular dimensions and in turn increasing the size of the active material above the membrane's pore-size exclusion limit.

Synthesis of Cycloparaphenyleneacetylene via Alkyne Metathesis: C Complexation and Copper-Free Triple Click Reaction.

Alkyne metathesis provided an efficient macrocyclization route to a cycloparaphenyleneacetylene derivative in high yield. The cavity size was suitably matched for C which was tightly bound in an induced-fit fashion. The strained alkynes enabled a copper-free, 3-fold azide-alkyne cycloaddition at 50 °C.

Evolutionary Design of Low Molecular Weight Organic Anolyte Materials for Applications in Nonaqueous Redox Flow Batteries.

The integration of renewable energy sources into the electric grid requires low-cost energy storage systems that mediate the variable and intermittent flux of energy associated with most renewables. Nonaqueous redox-flow batteries have emerged as a promising technology for grid-scale energy storage applications. Because the cost of the system scales with mass, the electroactive materials must have a low equivalent weight (ideally 150 g/(mol·e(-)) or less), and must function with low molecular weight supporting electrolytes such as LiBF4.

Conception and evolution of stereocontrolled strategies toward functionalized 8-aryloctanoic acids related to the total synthesis of aliskiren.

A detailed account is given describing the approaches used toward the total synthesis of aliskiren. In particular, ring-closing metathesis with the Hoveyda-Grubbs catalyst accelerates the formation of a 9-membered lactone from an (R)-ester. The diastereomeric (S)-ester leads to the formation of dimeric dilactones, which were characterized by X-ray analysis and chemical conversions.

Kinetic diastereomer differentiation in Au(III)- and Bi(III)-catalyzed benzylic arylation: concise and stereocontrolled synthesis of 2-amino-1,1-diarylalkanes.

Benzylic alcohols carrying an adjacent α-nitro or α-azido group on the alkane chain are converted into syn-1,1-diaryl-2-nitro- and 2-azidoalkanes with electron-rich arenes in stereoselective reactions catalyzed by Brønsted and Lewis acids. Gold(III) chloride and bismuth(III) triflate were found to be especially efficient as catalysts, showing kinetically controlled differentiation in the reactivity of diastereomeric α-substituted benzyl alcohols. Applications to therapeutically relevant syn- and anti- 2-amino-1,1-diarylalkanes are projected.

A new approach to the synthesis of peptidomimetic renin inhibitors: palladium-catalyzed asymmetric allylation of acyclic alkyl aryl ketones.

A new approach to the synthesis of Tekturna, a recently marketed drug for hypertension, takes advantage of a modified protocol of the Stoltz palladium-catalyzed asymmetric allylation with a t-BuPHOX ligand for the synthesis of allylated acyclic alkyl aryl ketones. The method led to an α-isopropyl α-allyl aryl ketone in 90% yield and 88 to 91% ee, which was used in the synthesis of an advanced intermediate toward Tekturna. A beneficial effect of protic additives, such as BHT (2,6-di-tert-butyl-p-cresol), on the time and enantioselectivity of the reaction was discovered.

Practical synthesis of quinoxalinones via palladium-catalyzed intramolecular N-arylations.

A practical and highly efficient route to the synthesis of pharmaceutically interesting quinoxalinone scaffolds is reported. The key step involves an intramolecular palladium-catalyzed N-arylation under microwave irradiation. The developed methodology tolerates a variety of bromoanilides to afford a diverse collection of bicyclic and polycyclic quinoxalinones in high yield.

Total synthesis of "aliskiren": the first Renin inhibitor in clinical practice for hypertension.

We report a "macrocycle route" toward aliskiren, a drug presently marketed for the treatment of hypertension, using a highly stereocontrolled approach starting from a common "isopropyl chiron". Highlights of the synthesis include a challenging RCM reaction to produce a nine-membered unsaturated lactone, a highly stereoselective catalytic Du Bois aziridination, and a regio- and diastereoselective aziridine ring-opening to a vicinal amino alcohol.