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The development of a system for the operationally simple, scalable conversion of polyhydroxylated biomass into industrially relevant feedstock chemicals is described. This system includes a bimetallic Pd/Re catalyst in combination with hydrogen gas as a terminal reductant and enables the high-yielding reduction of sugar acids. This procedure has been applied to the synthesis of adipate esters, precursors for the production of Nylon-6,6, in excellent yield from biomass-derived sources.

The enantioselective total syntheses of himandravine and GB17 were completed through a common biomimetic strategy involving Diels-Alder reactions of unusual double diene containing linear precursors. The double diene precursors, containing or lacking a C12 substituent as required to produce GB17 or himandravine, respectively, were found to undergo Diels-Alder reactions to afford mixtures of regioisomeric cycloadducts that map onto the alternative carbocyclic frameworks of both himandravine and GB17. Computational investigations revealed that these Diels-Alder reactions proceed via transition state structures of similar energy that have a high degree of bispericyclic character and that the low levels of regioselectivity observed in the reactions are a consequence of competing orbital interaction and distortion energies. The combined experimental and computational results provide valuable insights into the biosynthesis of the Galbulimima alkaloids.

The application of carboxy‐MIDA‐boronate (MIDA=N‐methyliminodiacetic acid) as an in situ CO surrogate for various palladium‐catalyzed transformations is described. Carboxy‐MIDA‐boronate was previously shown to be a bench‐stable boron‐containing building block for the synthesis of borylated heterocycles. The present study demonstrates that, in addition to its utility as a precursor to heterocycle synthesis, carboxy‐MIDA‐boronate is an excellent in situ CO surrogate that is tolerant of reactive functionalities such as amines, alcohols, and carbon‐based nucleophiles. Its wide functional‐group compatibility is highlighted in the palladium‐catalyzed aminocarbonylation, alkoxycarbonylation, carbonylative Sonogashira coupling, and carbonylative Suzuki–Miyaura coupling of aryl halides. A variety of amides, esters, (hetero)aromatic ynones, and bis(hetero)aryl ketones were synthesized in good‐to‐excellent yields in a one‐pot fashion. [ABSTRACT FROM AUTHOR]

The application of carboxy-MIDA-boronate (MIDA=N-methyliminodiacetic acid) as an in situ CO surrogate for various palladium-catalyzed transformations is described. Carboxy-MIDA-boronate was previously shown to be a bench-stable boron-containing building block for the synthesis of borylated heterocycles. The present study demonstrates that, in addition to its utility as a precursor to heterocycle synthesis, carboxy-MIDA-boronate is an excellent in situ CO surrogate that is tolerant of reactive functionalities such as amines, alcohols, and carbon-based nucleophiles. Its wide functional-group compatibility is highlighted in the palladium-catalyzed aminocarbonylation, alkoxycarbonylation, carbonylative Sonogashira coupling, and carbonylative Suzuki-Miyaura coupling of aryl halides. A variety of amides, esters, (hetero)aromatic ynones, and bis(hetero)aryl ketones were synthesized in good-to-excellent yields in a one-pot fashion., (© 2020 Wiley-VCH GmbH.)