Biobased Polymers Enabling the Synthesis of Ultralong Silver Nanowires and Other Nanostructures.

Conventional polyol synthesis of silver nanowires has exclusively relied on polyvinylpyrrolidone (PVP), a nonbiodegradable polymer with no viable alternatives. The underlying reaction mechanism remains unclear. Herein, we discovered a new sustainable solution by employing biobased cellulose derivatives, including hydroxyethyl cellulose (HEC), as effective substitutes for PVP.

Total Synthesis of Neuroprotective Agents, (+)-Lycibarbarine A and (-)-Lycibarbarine B.

We describe the convergent total syntheses of lycibarbarines A and B which are potent neuroprotective agents recently isolated from the fruits of . The synthesis highlights the construction of a unique spiro oxazine heterocyclic motif imbedded in these natural products. The synthesis is accomplished from the commercially available 8-hydroxyquinaline and 2-deoxy-d-ribose as key starting materials.

Convergent synthesis of (+)-carambolaflavone A, an antidiabetic agent using a bismuth triflate-catalyzed -aryl glycosylation.

We describe a convergent total synthesis of carambolaflavone A, a natural flavonoid -aryl glycoside with significant antihyperglycemic properties. The synthesis features a bismuth triflate-catalyzed stereoselective -aryl glycosylation of a flavan derivative and an appropriately protected D-fucose derivative as the key step. Inexpensive and non-toxic bismuth triflate provided the best results among various other Lewis acids screened for this -aryl glycosylation.

The Chiron Approach to (3,3,6)-Hexahydrofuro[2,3-]furan-3-ol, a Key Subunit of HIV-1 Protease Inhibitor Drug, Darunavir.

We describe an enantioselective synthesis of (3,3,6)-hexahydrofuro[2,3-]furan-3-ol which is a key subunit of darunavir, a widely used HIV-1 protease inhibitor drug for the treatment of HIV/AIDS patients. The synthesis was achieved in optically pure form utilizing commercially available sugar derivatives as the starting material. The key steps involve a highly stereoselective substrate-controlled hydrogenation, a Lewis acid catalyzed anomeric reduction of a 1,2--isopropylidene-protected glycofuranoside, and a Baeyer-Villiger oxidation of a tetrahydrofuranyl-2-aldehyde derivative.

Potent HIV-1 Protease Inhibitors Containing Carboxylic and Boronic Acids: Effect on Enzyme Inhibition and Antiviral Activity and Protein-Ligand X-ray Structural Studies.

We report the synthesis and biological evaluation of phenylcarboxylic acid and phenylboronic acid containing HIV-1 protease inhibitors and their functional effect on enzyme inhibition and antiviral activity in MT-2 cell lines. Inhibitors bearing bis-THF ligand as P2 ligand and phenylcarboxylic acids and carboxamide as the P2' ligands, showed very potent HIV-1 protease inhibitory activity. However, carboxylic acid containing inhibitors showed very poor antiviral activity relative to carboxamide-derived inhibitors which showed good antiviral IC value.

A Photochemical Route to Optically Active Hexahydro-4-furopyranol, a High-Affinity P2 Ligand for HIV-1 Protease Inhibitors.

We describe here the syntheses of optically pure (3a,4,7a)-hexahydro-4-furo[2,3-]pyran-4-ol and (3a,4,7a)-hexahydro-4-furo[2,3-]pyran-4-ol. These stereochemically defined heterocycles are important high-affinity P2 ligands for a variety of highly potent HIV-1 protease inhibitors. The key steps involve an efficient Paternò-Büchi [2 + 2] photocycloaddition, catalytic hydrogenation, acid-catalyzed cyclization to form the racemic ligand alcohol, and an enzymatic resolution with immobilized Amano Lipase PS-30.