Publications by authors named "Barbara Riehl"

Arylated products are found in various fields of chemistry and represent essential entities for many applications. Therefore, the formation of this structural feature represents a central issue of contemporary organic synthesis. By the action of electricity the necessity of leaving groups, metal catalysts, stoichiometric oxidizers, or reducing agents can be omitted in part or even completely.

View Article and Find Full Text PDF

The development of a convenient and rapid method to synthesize radiolabeled, enantiomerically pure amino acids (AAs) as potential positron emission tomography (PET) imaging agents for mapping various biochemical transformations in living organisms remains a challenge. This is especially true for the synthesis of carbon-11-labeled AAs given the short half-life of carbon-11 ( C, t =20.4 min).

View Article and Find Full Text PDF

A stereoselective and electrocatalytic coupling reaction of isoeugenol has been reported for the first time in a 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)/boron-doped diamond (BDD) electrode system. This particular C-C bond formation and diastereoselectivity is driven by a solvate interaction between the radical species and another isoeugenol molecule. Due to an electrocatalytic cycle, only understoichiometric amounts of charge are necessary.

View Article and Find Full Text PDF

Electro-organic synthesis is a powerful technique for the sustainable preparation of compounds. However, many electrosynthetic reactions require complex equipment, are limited to a very narrow current density range, or have very long reaction times; some also involve nonselective transformations and bad scalability. The robust and selective synthesis of nonsymmetric biphenols and partially protected derivatives is established by anodic C-C cross-coupling.

View Article and Find Full Text PDF
Article Synopsis
  • - The western corn rootworm (WCR) is a major pest affecting maize, and breeding for tolerance is a potential solution, but current methods lack sufficient understanding and tools for assessment.
  • - Researchers developed advanced techniques like positron emission tomography and radiometabolite flux analysis to study how maize adapts to WCR attacks, revealing specific changes in root growth and auxin biosynthesis.
  • - The study found that WCR attacks lead to an increase in certain amino acids and a significant shift in auxin production, suggesting that monitoring these changes could help in breeding corn that is more resilient to this pest.
View Article and Find Full Text PDF

Carbon-11 (β(+) emitter, t1/2 = 20.4 min) radiolabeled L-glutamine is a potentially useful molecular imaging agent that can be utilized with positron emission tomography for both human oncological diagnosis and plant imaging research. Based upon a previously reported [(11)C]cyanide end-capping labeling method, a systematic investigation of nucleophilic cyanation reactions and acidic hydrolysis reaction parameters, including base, metal ion source, phase transfer catalyst, solvent, reaction temperature and reaction time, was conducted.

View Article and Find Full Text PDF