High-temperature water unlocks urea as nitrogen-source towards imidazoles.

Urea is a non-toxic, harmless, and abundant bulk organic chemical featuring high nitrogen content. Therefore, urea could be a prime green candidate for introducing nitrogen atoms into organic molecules. In this regard, urea in organic synthesis has been mainly employed as building block, component of solvent systems, catalyst, or for pH adjustment, while uses of urea as NH-source towards the construction of small organic compounds are scarce.

Green Hydrothermal Synthesis of Fluorescent 2,3-Diarylquinoxalines and Large-Scale Computational Comparison to Existing Alternatives.

Invited for this month's cover is the group of Miriam Unterlass at the Technische Universität Wien and the CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences. The image illustrates the synthesis of quinoxalines in "hot water" and the large-scale computational comparison of all existing syntheses of these quinoxalines. The Full Paper itself is available at 10.

Semisynthesis of Dolabellane Diterpenes: Oxygenated Analogues with Increased Activity against Zika and Chikungunya Viruses.

Brown algae and soft corals represent the main marine sources of dolabellane diterpenes. The antiviral activity of dolabellanes has been studied for those isolated from algae, whereas dolabellanes isolated from soft corals have been barely studied. In this work, a collection of dolabellane diterpenes consisting of five natural and 21 semisynthetic derivatives was constructed, and their antiviral activities against Zika (ZIKV) and Chikungunya (CHIKV) viruses were tested.

Green Hydrothermal Synthesis of Fluorescent 2,3-Diarylquinoxalines and Large-Scale Computational Comparison to Existing Alternatives.

Here, the hydrothermal synthesis (HTS) of 2,3-diarylquinoxalines from 1,2-diketones and o-phenylendiamines (o-PDAs) was achieved. The synthesis is simple, fast, and generates high yields, without requiring any organic solvents, strong acids or toxic catalysts. Reaction times down to <10 min without decrease in yield could be achieved through adding acetic acid as promoter, even for highly apolar biquinoxalines (yield >90 % in all cases).

Screening of acetylcholinesterase inhibitors in marine organisms from the Caribbean Sea.

The acetylcholinesterase inhibitory activity of 89 organic extracts from marine organisms was evaluated through a TLC bioautography methodology. Extracts from soft corals ( and ) were the most active compared with extracts from sponges. The bioguided chemical study of the most active extract, obtained from , led to the isolation of a diterpene with spectroscopic properties consistent to those published to the cembrane Steylolide.