An unprecedented cross-dehydrogenative-coupling (CDC) reaction of saturated aldehyde β-C-H with arenes to form cinnamaldehydes via the cleavages of four C-H bonds has been developed. The reaction possesses complete E-stereoselectivity for the C═C double bond. The protocol is featured by atom and step economy, mild reaction conditions, and convenient operation.
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http://dx.doi.org/10.1021/acs.orglett.9b00695 | DOI Listing |
J Am Chem Soc
January 2025
EaStCHEM School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, U.K.
New approaches to achieve facile and reversible dihydrogen activation are of importance for synthesis, catalysis, and hydrogen storage. Here we show that low-coordinate magnesium oxide complexes [{(nacnac)Mg}(μ-O)] , with nacnac = HC(RCNDip), Dip = 2,6-PrCH, R = Me (), Et (), Pr (), readily react with dihydrogen under mild conditions to afford mixed hydride-hydroxide complexes [{(nacnac)Mg}(μ-H)(μ-OH)] . Dehydrogenation of complexes is strongly dependent on remote ligand substitution and can be achieved by simple vacuum-degassing of (R = Pr) to regain .
View Article and Find Full Text PDFDalton Trans
January 2025
Institute of Inorganic Chemistry, Georg-August-Universität Göttingen, Göttingen Tammannstrasse 4, D-37077, Germany.
The reactions of LAlH (L = HC(CMeNAr), Ar = 2,6-PrCH) (1) with diphenylphosphane oxide [PhP(O)H], diphenylphosphinamide [PhP(O)NH], and diaryl/alkyl phosphane [(RO)P(O)H (R = Ph, or Pr)] afford their corresponding compounds with compositions LAl(H)OP(Ph) (2), LAl[OP(Ph)] (3), LAl{[N(H)P(O)(Ph)][OP(Ph)]} (4), LAl(OPr) (5), and LAl(OPh) (6), respectively. These reactions probably undergo a process of dehydrogenation coupling, deaminating dehydrogenation coupling, or chain-breaking coupling. It is noteworthy to mention that the reaction of compound 1 with 2 equiv.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Northeast Forestry University, Chemical Engineering and Resource Utilization, CHINA.
Electrochemical 5-hydroxymethylfurfural (HMF) oxidation reaction (HMFOR) offers a promising route to transform biomass into value-added chemicals. However, the competing oxygen evolution reaction (OER) greatly limits the HMFOR selectivity. Herein, we report a facile doping strategy to engineer oxygen intermediates adsorption on amorphous NiFe alloys to boost highly selective electrochemical HMF oxidation to produce 2,5-furandicarboxylic acid (FDCA), among which, amorphous Mn-doped NiFeB alloy displays a low HMFOR onset potential of 1.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Shanghai Institute of Ceramics Chinese Academy of Sciences, State Key Laboratory of High Performance Ceramics and Superfine Microstructure, CHINA.
Pairing photocatalytic 1,2,3,4-tetrahydroisoquinoline semi-dehydrogenation reaction (THIQ-SDR) with two-electron oxygen reduction reaction (2e- ORR) is a green solar to chemical strategy by simultaneously utilizing the photo-excited electrons and holes. However, it is still short of high-efficiency photocatalyst to drive two reactions above. In the present work, crystalline pyrene-thiourea/urea covalent organic frameworks (COF-Py-S and -O) were synthesized and demonstrated as high-performance metal-free photocatalysts.
View Article and Find Full Text PDFNat Commun
January 2025
Engineering Center of Catalysis and Synthesis for Chiral Molecules, Department of Chemistry, Fudan University, Shanghai, 200433, China.
Flow chemistry has many advantages over batch synthesis of organic small-molecules in terms of environmental compatibility, safety and synthetic efficiency when scale-up is considered. Herein, we report the 10-step chemo-biocatalytic continuous flow asymmetric synthesis of cyproterone acetate (4) in which 10 transformations are combined into a telescoped flow linear sequence from commercially available 4-androstene-3, 17-dione (11). This integrated one-flow synthesis features an engineered 3-ketosteroid-Δ-dehydrogenase (ReM2)-catalyzed Δ-dehydrogenation to form the C1, C2-double bond of A ring, a substrate-controlled Co-catalyzed Mukaiyama hydration of 9 to forge the crucial chiral C17α-OH group of D ring with excellent stereoselectivity, and a rapid flow Corey-Chaykovsky cyclopropanation of 7 to build the cyclopropyl core of A ring.
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