Polystyrene-Supported N-Heterocyclic Carbene-Silver Complexes as Robust and Efficient Catalysts for the Reaction of Carbon Dioxide and Propargylic Alcohols
supported catalysts was investigated for the reaction of propargylicalcohols and carbondioxide. PS‐NHC‐Cu(I) showed no catalytic activity to the reaction, while PS‐NHC‐Ag(I) showed a considerable high activity and selectivity for the reaction, yielding the corresponding α‐alkylidene cyclic carbonates in high to excellent yields under mild conditions. Most importantly, the supported catalysts could be
propargyl alcohols at roomtemperature. The electrosynthesis was successfully carried out with a copper anode and a nickel cathode in an undivided cell containing n-Bu4NBr–MeCN electrolyte with a constant current under 3 MPa pressure of CO2, and the α-alkylidene cyclic carbonates were obtained in good to excellent isolated yields in the secondary and tertiary terminal propargylic alcohols cases. The
Insights into the Activation of Alkyne-Installed Glycosyl Donors with Dual Acidic Metal Catalysts: Reaction Pathway, Influencing Factors, and Enlightenment for Glycosylation
The activation of alkyne-installed glycosyldonors with dual acidic metal catalysts were studied. Lewis and/or π acidity-activated pathways were observed for alkynyl carbonate-, ester-, and ether-type donors, and π acidity-promoted reaction mode afforded higher efficiency and yields. The activation mode for a certain metal catalyst is determined by the nature of catalysts itself, protecting groups
Copper-catalysed synthesis of α-alkylidene cyclic carbonates from propargylic alcohols and CO<sub>2</sub>
作者:Alejandro Cervantes-Reyes、Kaveh Farshadfar、Matthias Rudolph、Frank Rominger、Thomas Schaub、Alireza Ariafard、A. Stephen K. Hashmi
DOI:10.1039/d0gc03990j
日期:——
propargylic alcohols and carbondioxide at room temperature. By using the combination of a sterically demanding BPDPrCuCl complex (BPDPr = 1,3-bis(2,6-diisopropylphenyl)-1,3-diazonine-2-ylidene) and CsF, as catalytic system, primary propargylic alcohols are efficiently converted to the corresponding α-alkylidenecycliccarbonates. Gram scale (up to 89% yield) and reusability experiments (74% global