0000000000808378
AUTHOR
Gerald B. Hammond
Acidic Co-Catalysts in Cationic Gold Catalysis.
A systematic study on the effects of Lewis or Bronsted acid co-catalysts in gold-catalyzed reactions was undertaken using representative reactions (O-, N-, and C-nucleophilic additions to alkynes). Through these reactions, it was demonstrated that an acidic co-catalyst can increase the catalyst turnover significantly, enabling practical reaction rates at competitive catalyst loadings (<1 mol %). Further investigation is currently underway to improve the understanding of the subtle principles underlying these experimental observations.
Metal-Free and User-Friendly Regioselective Hydroxyfluorination of Olefins
A simple, user-friendly, metal-free protocol for the regioselective anti-Markovnikov hydrofluorination of olefins using readily available and inexpensive reagents has been developed. This new approach displays a broader scope than previously reported methodologies and has been applied to the late-stage fluorination of a complex molecule, giving rise to a fluorosteroid derivative. The stereochemistry of the process has also been studied in some detail.
AuX3-Mediated Selective Head-to-Head Dimerization of Difluoropropargyl Amides
A dimerization of difluoropropargyl amides by reaction with gold(III) halides is described. A reductive elimination of a divinylgold species can be invoked to rationalize its formation. Initial studies of the unusual reactivity of these 1,4-dihalo-1,3-dienes have been performed.
The history and future challenges associated with the hydrogenation of vinyl fluorides
Abstract Catalytic hydrogenation is one of the most powerful transformations available in synthetic chemistry; there have been three Nobel Laureates rewarded for their work in the field. Despite the advances in substrate scope and the development of enantioselective versions of this transformation, vinyl fluorides remain somewhat underrepresented. Successful hydrogenation of vinyl fluorides can give rise to a fluorine-containing stereocenter, an important feature which has great potential in many areas of chemistry. This review aims to explore the history of vinyl fluorides as substrates in hydrogenation reactions, and to highlight modern day challenges and unresolved issues regarding this …