Experimental and Computational Evidence of non-MEP Pathways in the Fragmentation and Rearrangement of Bicyclo[3.3.1] heptane Diazonium Ions

The non-minimum energy pathways on the fragmentation of bicyclic diazoniumions and subsequent carbocationic rearrangements has been studied by a combination of computational chemistry (MD simulations, IRC, stationary point analysis) and experiments (TR-IR and UV from ps to µs, NMR kinetics).<div><br></div>

Experimental and Computational Evidence of non-MEP Pathways in the Fragmentation and Rearrangement of Bicyclo[3.3.1] heptane Diazonium Ions

The non-minimum energy pathways on the fragmentation of bicyclic diazoniumions and subsequent carbocationic rearrangements has been studied by a combination of computational chemistry (MD simulations, IRC, stationary point analysis) and experiments (TR-IR and UV from ps to µs, NMR kinetics).<div><br></div>

Warning on False or True Morels and Button Mushrooms with Potential Toxicity Linked to Hydrazinic Toxins: An Update

Recently, consumption of the gyromitrin-containing neurotoxic mushroom Gyromitra sp. (false morel), as gourmet food was hypothesized to play a role in sporadic amyotrophic lateral sclerosis genesis. The present review analyses recent data on edibility and toxicity of false and true morels and Agaricus spp. Controversy about the toxic status of Gyromitra esculenta was due to variable toxin susceptibility within consumers. We suggest that Verpa bohemica, another false morel, is also inedible. We found a temporary neurological syndrome (NS) with cerebellar signs associated with high consumption of fresh or dried true morels Morchella sp. After ingestion of crude or poorly cooked fresh or dried morels, a gastrointestinal “haemolytic” syndrome was also observed. Agaritine, a water soluble hydrazinic toxin closely related to gyromitrin is present along with metabolites including diazonium ions and free radicals, in Agaricus spp. and A. bisporus, the button mushroom, and in mice after ingestion. It is a potential weak carcinogen in mice, but although no data are available for humans, a lifetime low cumulative extra cancer risk in humans can be estimated to be about 10−5. To conclude, a safety measure is to avoid consuming any true morels or button mushrooms when crude or poorly cooked, fresh or dried.

Synthesis of Aromatic and Aliphatic Di-, Tri-, and Tetrasulfonic Acids

Oligosulfonic acids are promising linker compounds for coordination polymers and metal-organic frameworks, however, compared to their carboxylic acid congeners, often not readily accessible by established synthetic routes. This Account highlights the synthesis of recently developed aromatic and aliphatic di-, tri- and tetrasulfonic acids. While multiple electrophilic sulfonations of aromatic substrates are rather limited, the nucleophilic aromatic substitution including an intramolecular variant, the Newman–Kwart rearrangement, allows the flexible introduction of up to four sulfur-containing moieties at an aromatic ring. Sulfonic acids are then accessed by oxidation of thiols, thioethers, or thioesters either directly with hydrogen peroxide or in two steps with chlorine (generated in situ from N-chlorosuccinimide/hydrochloric acid) to furnish sulfochlorides which are subsequently hydrolyzed. In the aliphatic series, secondary alcohols as starting materials are converted into thioethers, thioesters, or thiocarbonates by nucleophilic substitutions, which are also subsequently oxidized to furnish sulfonic acids.1 Introduction2 Electrophilic Aromatic Substitution3 Nucleophilic Aromatic Substitution3.1 Intermolecular SNAr3.2 Intermolecular with Subsequent Oxidation3.3 Intramolecular with Subsequent Oxidation4 Nucleophilic Aliphatic Substitution with Subsequent Oxidation5 Oxidation5.1 Oxidation of Thiocarbonates5.2 Oxidation of Thioethers5.3 Oxidation of Thioesters6 Thermolysis of Neopentylsulfonates7 Functionalization via Diazonium Ions8 Conclusion