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The production of essential oils by steam distillation is invariably associated with large amounts of organic waste which is normally disposed of or returned to the fields, although it may still contain some valuable components. In particular, Cannabis sativa essential oil produced by steam distillation of the apical part of industrial hemp plants yields a soaked biomass residue that may contain high-value cannabinoids. From the perspective of sustainable exploitation of agricultural resources, a method to extract cannabidiol (CBD) from such waste was demonstrated and scaled-up, using bioethanol as a renewable bio-based solvent and without requiring chromatographic separation, with an overall yield of 10.1 mg CBD per g waste. The work paves the way to an integrated complete utilisation of industrial hemp byproducts. Furthermore, two alternative lipase-mediated chemo-enzymatic derivatisations have been designed and optimised for the conversion of the recovered CBD into cannabielsoin (CBE), an underexploited cannabinoid with attractive bioactivity. The processes are practical and efficient, with 31--47% isolated yields and green metrics comparing well with the established chemical alternatives. [ABSTRACT FROM AUTHOR]

A sustainable upgrading of renewable bulk materials, obtained by decomposition of biomass lignocellulose, could facilitate their use in the industrial production of chemicals. Homogeneous ruthenium catalysis plays a fundamental role in this area. The review deals with the upgradation of lignocellulosic molecules through the formation of new C−C and C−N bonds. Selected examples of catalytic bond forming reactions reported until mid of 2023, include: (a) dehydrogenative based couplings of alcohols, (b) reductive amination of carbonyl compounds, (c) direct C−H functionalization of (hetero)aromatic compounds. These approaches fulfill the requirements of sustainability: application occurs without any previous substrate activation, thus reducing the production of waste. New chemicals containing the intrinsic molecular structure of lignocellulose substrates, showed a broad range of applications: green fuels, hydrogen carriers, monomers of polymers, intermediates of fine chemicals and pharmaceuticals. The results discussed in the review could inspire the reader to improve the valorization process, in terms of bio‐substrate scope as well as product complexity, through more strategic applications of the catalytic methods. [ABSTRACT FROM AUTHOR]

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Keywords: Functionalisation; Late-stage; N-heterocycle; Pyridines; Selectivity EN Functionalisation Late-stage N-heterocycle Pyridines Selectivity 1 1 1 04/24/23 20230420 NES 230420 B The Front Cover Cover b illustrates how the pyridine ring of the antihistamine loratadine can be selectively functionalised at the I ortho i -, I meta i -, or I para i -position (each of them activated by a thunder). Indeed, the selective functionalisation of this N-heterocycle is often problematic, thus a lighthouse guides the chemists through the late-stage functionalisations of pyridine-containing biomolecules. Functionalisation, Late-stage, N-heterocycle, Pyridines, Selectivity. [Extracted from the article]