Polyketides are a large family of bioactive natural products synthesized by polyketide synthase (PKS) enzyme complexes predominantly from acetate and propionate. Given the structural diversity of compounds produced using these two simple building blocks, there has been longstanding interest in engineering the incorporation of alternative extender units. We have been investigating the mechanism ...

An enantioselective hydrogenation of fluorinated hydrazones has been achieved by employing [Pd(R)-DTBM-SegPhos(OCOCF3)2] as the catalyst, providing a general and convenient method toward chiral fluorinated hydrazines. A broad substrate scope including β-aryl-, γ-aryl-, and alkyl-chain-substituted hydrazones worked efficiently in high yields and up to 94% of enantioselectivity. The reductive ami...

This work describes a strategy to mitigate the undesirable transport of small molecules among aqueous droplets immersed in fluorinated oil by replacing surfactant molecules with nanoparticles as emulsion stabilizers (Pickering emulsions). Amphiphilic silica particles were synthesized and redispersed in fluorinated solvents, and monodispersed picoliter aqueous drops were generated from flow-focu...

Fluorinated, contorted hexabenzocoronenes (HBCs) have been synthesized in a facile manner via Suzuki-Miyaura coupling of fluorinated phenyl boronic acids followed by photocyclization and Scholl cyclization. In addition to the molecular conformation observed in previous HBC derivatives, close-contact fluorine-fluorine intramolecular interactions result in a metastable conformation not previously...

On the one hand, owing to its electronegativity, relatively small size, and notable leaving group ability from anionic intermediates, fluorine offers unique opportunities for mechanism-based enzyme inhibitor design. On the other, the "bio-orthogonal" and NMR-active 19-fluorine nucleus allows the bioorganic chemist to follow the mechanistic fate of fluorinated substrate analogues or inhibitors a...

Fluorine-19 ((19)F) MRI of the lungs using inhaled inert fluorinated gases can potentially provide high quality images of the lungs that are similar in quality to those from hyperpolarized (HP) noble gas MRI. Inert fluorinated gases have the advantages of being nontoxic, abundant, and inexpensive compared with HP gases. Due to the high gyromagnetic ratio of (19)F, there is sufficient thermally ...

A significant proportion of pharmaceuticals are fluorinated and selecting the site of fluorine incorporation can be an important beneficial part a drug development process. Here we describe initial experiments aimed at the development of a general method of selecting optimum sites on pro-drug molecules for fluorination, so that metabolic stability may be improved. Several model biphenyl derivat...

Substitution of leucine residues by 5,5,5-trifluoroleucine at the d-positions of the leucine zipper peptide GCN4-p1d increases the thermal stability of the coiled-coil structure. The midpoint thermal unfolding temperature of the fluorinated peptide is elevated by 13 degrees C at 30 microM peptide concentration. The modified peptide is more resistant to chaotropic denaturants, and the free energ...

Vapour thermolysis processes of copper(I1) bis-chelate complexes with different p-diketones in the 160640°C temperature range were studied by using the high-temperature source of a molecular beam with mass spectrometric recording of the gas phase composition directly at the outlet from the thermal reactor. Schemes of a heterogeneous decomposition of these compounds vapour were suggested on the ...