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.

Herein we report the 3,5bistrifluoromethylphenyl urea-catalyzed functionalization of unactivated C-H bonds. In this system, the urea catalyst mediates the formation of high-energy vinyl carbocations that undergo facile C-H insertion and Friedel-Crafts reactions. We introduce a new paradigm for these privileged scaffolds where the combination of hydrogen bonding motifs and strong bases affords highly active Lewis acid catalysts capable of ionizing strong C-O bonds. Despite the highly Lewis acidic nature of these catalysts that enables triflate abstraction from sp 2 carbons, these newly found reaction conditions allow for the formation of heterocycles and tolerate highly Lewis basic heteroaromatic substrates. This strategy showcases the potential utility of dicoordinated vinyl carbocations in organic synthesis.

The electrochemical generation of vinyl carbocations from alkenyl boronic esters and boronates is reported. Using easy-tohandle nucleophilic fluoride reagents, these intermediates are trapped to form fully substituted vinyl fluorides. Mechanistic studies support the formation of dicoordinated carbocations through sequential single-electron oxidation events. Notably, this electrochemical fluorination features fast reaction times and Lewis acid-free conditions. This transformation provides a complementary method to access vinyl fluorides with simple fluoride salts such as TBAF.

Cyclopropanated allylboration reagents participate in homoallylation reactions of aliphatic and aromatic aldehydes, generating allylicsubstituted alkenes that are difficult to produce via other methods. In studying the effect of cyclopropane substituents, we discovered that an aryl substituent completely changes the outcome to cyclopropylcarbinylation, as if the cyclopropylcarbinyl fragment were transferred intact. However, density functional theory computation suggested a novel mechanism involving ring opening and reclosure, which is supported by experimental evidence.

Herein we report the 3,5bistrifluoromethylphenyl urea-catalyzed functionalization of unactivated C–H bonds. In this system, the urea catalyst mediates the formation of high-energy vinyl carbocations that undergo facile C–H insertion and Friedel–Crafts reactions. We introduce a new paradigm for these privileged scaffolds where the combination of hydrogen bonding motifs and strong bases affords highly active Lewis acid catalysts capable of ionizing strong C–O bonds. Despite the highly Lewis acidic nature of these catalysts that enables triflate abstraction from sp² carbons, these newly found reaction conditions allow for the formation of heterocycles and tolerate highly Lewis basic heteroaromatic substrates. This strategy showcases the potential utility of dicoordinated vinyl carbocations in organic synthesis.<br>