Stabilized Palladium Nanoparticles from Bis-(N-benzoylthiourea) Derived-PdII Complexes as Efficient Catalysts for Sustainable Cross-Coupling Reactions in Water

Stable palladium (II) complexes, incorporating a double (N-benzoylthiourea) arrangement bonded to a complex heterocyclic scaffold, are used as precursors of catalytic species able to promote Suzuki-Miyaura, Mizoroki-Heck, Hiyama, Buchwald-Hartwig, Hirao and Sonogashira-Hagihara cross-coupling transformations in water. These sustainable processes are chemoselective and very versatile. The nanoparticles responsible for these catalytic reactions were analyzed and studied. Their usefulness is demonstrated after several tests and analyses. The heterogeneous character of this species in water was also confirmed.

Phosphine Catalyzed Michael-Type Additions: The Synthesis of Glutamic Acid Derivatives from Arylidene-α-amino Esters

The reaction of arylidene-α-amino esters with electrophilic alkenes to yield Michael-type addition compounds is optimized using several phosphines as organocatalysts. The transformation is very complicated due to the generation of several final compounds, including those derived from the 1,3-dipolar cycloadditions. For this reason, the selection of the reaction conditions is a very complex task and the slow addition of the acrylic system is very important to complete the process. The study of the variation in the structural components of the starting imino ester is performed as well as the expansion of other electron-poor alkenes. The crude products have a purity higher than 90% in most cases without any purification. A plausible mechanism is detailed based on the bibliography and the experimental results. The synthesis of pyroglutamate entities, after the reduction of the imino group and cyclization, is performed in high yields. In addition, the hydrolysis of the imino group, under acidic media, represents a direct access to glutamate surrogates.

Optimization of lignocellulolytic bacterial inoculum and substrate mix for lignocellulose degradation and product quality on co-composting of green waste with food waste

The present study evaluates the effect of the mixing ratio of substrates and inoculation with lignocellulolytic bacteria on green waste (GW) and food waste (FW) co-composting. A Box-Behnken design was used to simultaneously optimize the lignocellulose degradation (%LD) and end-product quality. The best operational conditions were 4.85*10⁵ CFU g^-1 of Bacillus sp. F3X3 and 1.44*10⁶ CFU g^-1 of Paenibacillus sp. F1A5 with a substrate mixture containing 50% GW, 32.5% unprocessed FW, 2.5% processed FW, 13% sawdust, and 2% phosphate rock; with a C/N ratio of 27. Under these conditions, the %LD was 33% and the end-product has pH 8.3, TOC 22,4%, TN 1,7%, and a germination index of 103%. Therefore, the product complies with quality standards for organic fertilizers. The results of this study allow the identification of appropriate strategies to optimize GW composting, increasing the degradation of lignocellulose and improving the end-product quality.