Eco-friendly and ready-to-market polyurethanes: a Design of Experiment-guided substitution of toxic catalyst and fossil-based isocyanate.

In this contribution, we tackle the replacement of the Hg-based catalyst and fossil-derived isocyanate precursors toward the formulation of a more sustainable polyurethane thermosetting resins (PUs), emulating the performance of a fully fossil-based one employed in industrial encapsulation of optoelectronics. A mixed Bi-Zn catalyst and a 71% bio-based isocyanate are exploited at this aim through multivariate chemometric approaches, namely Design of Experiment (DoE). DoE allows us to investigate the effect of different formulation factors on selected parameters, such as the film flexibility and transparency or the gel time.

Efficient One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1)-ones via a Three-Component Biginelli Reaction.

Multicomponent reactions are considered to be of increasing importance as time progresses due to the economic and environmental advantages such strategies entail. The three-component Biginelli reaction involves the combination of an aldehyde, a β-ketoester and urea to produce 3,4-dihydropyrimidin-2(1)-ones, also known as DHPMs. The synthesis of these products is highly important due to their myriad of medicinal properties, amongst them acting as calcium channel blockers and antihypertensive and anti-inflammatory agents.

Synthetic Approach to the Preparation of (2-Acetoxy)allyl Nitro Compounds.

A synthetic approach to a new class of allyl nitro derivatives is reported. (2-Acetoxy)allyl nitro compounds have been prepared for the first time in a four-step procedure by a preliminary reaction of nitroalkanes with 2-(phenylselenyl)acetaldehyde. After the acetylation of the obtained nitro alcohols, the unsaturation is installed by an oxidation reaction involving the phenylselenyl group followed by a thermal elimination.