Hong-Yu Hou

Bio: Hong-Yu Hou is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Electrophilic addition & Protonation. The author has co-authored 1 publications.

Direct 1,2-Dicarbonylation of Alkenes towards 1,4-Diketones via Photocatalysis.

Abstract: 1,4-Dicarbonyl compounds are intriguing motifs and versatile precursors in numerous pharmaceutical molecules and bioactive natural compounds. Direct incorporation of two carbonyl groups into a double bond at both ends is straightforward, but also challenging. Represented herein is the first example of 1,2-dicarbonylation of alkenes by photocatalysis. Key to success is that N(n-Bu)4 + not only associates with the alkyl anion to avoid protonation, but also activates the α-keto acid to undergo electrophilic addition. The α-keto acid is employed both for acyl generation and electrophilic addition. By tuning the reductive and electrophilic ability of the acyl precursor, unsymmetric 1,4-dicarbonylation is achieved for the first time. This metal-free, redox-neutral and regioselective 1,2-dicarbonylation of alkenes is executed by a photocatalyst for versatile substrates under extremely mild conditions and shows great potential in biomolecular and drug molecular derivatization.

Direct decarboxylative Giese reactions.

Abstract: The quest to find milder and more sustainable methods to generate highly reactive, carbon-centred intermediates has led to a resurgence of interest in radical chemistry. In particular, carboxylic acids are seen as attractive radical precursors due their availability, low cost, diversity, and sustainability. Moreover, the corresponding nucleophilic carbon-radical can be easily accessed through a favourable radical decarboxylation process, extruding CO2 as a traceless by-product. This review summarizes the recent progress on using carboxylic acids directly as convenient radical precursors for the formation of carbon-carbon bonds via the 1,4-radical conjugate addition (Giese) reaction.

Photoredox-Enabled Chromium-Catalyzed Alkene Diacylations

Abstract: Transition-metal-catalyzed cross-coupling reactions are a powerful tool to construct carbon–carbon bonds in modern synthetic chemistry. Chromium catalysis is much less developed compared with the widely used palladium and nickel catalysis. Herein, we reported an efficient and flexible chromium-catalyzed radical diacylation of alkenes with the help of visible-light photoredox catalysis, giving access to valuable 1,4-, 1,6-, and 1,7-diones under mild conditions. The synthetic utility of this methodology was proven by converting diones to diverse heterocycles. Furthermore, the same dual catalysis system can be successfully applied to dienes and vinyl cyclopropanes. A possible mechanism of alkene diacylation via dual photoredox/chromium catalysis was proposed according to control experiments and DFT calculations.

Three-component carboacylation of alkenes via cooperative nickelaphotoredox catalysis

Abstract: Various commercially available acyl chlorides, aldehydes, and alkanes were exploited for versatile three-component 1,2-carboacylations of alkenes to forge two vicinal C–C bonds through the cooperative action of nickel and sodium decatungstate catalysis. A wealth of ketones with high levels of structural complexity was rapidly obtained via direct functionalization of C(sp2)/C(sp3)–H bonds in a modular manner. Furthermore, a regioselective late-stage modification of natural products showcased the practical utility of the strategy, generally featuring high resource economy and ample substrate scope.