Borrowing hydrogen: iridium-catalysed reactions for the formation of C–C bonds from alcohols
作者:Phillip. J. Black、Gerta Cami-Kobeci、Michael G. Edwards、Paul A. Slatford、Michael K. Whittlesey、Jonathan M. J. Williams
DOI:10.1039/b511053j
日期:——
Alcohols have been employed as substrates for C-C bond-forming reactions which involve initial activation by the temporary removal of hydrogen to form an aldehyde. The intermediate aldehyde is converted into an alkene via a Horner-Wadsworth-Emmons reaction, nitroaldol and aldol reactions. The 'borrowed hydrogen' is then returned to the alkene to form a C-C bond.
C–C Bond formation from alcohols using a Xantphos ruthenium complex
作者:Paul A. Slatford、Michael K. Whittlesey、Jonathan M.J. Williams
DOI:10.1016/j.tetlet.2006.07.069
日期:2006.9
A rutheniumcomplex of Xantphos has been shown to be a good catalyst for the alkylation of active methylene compounds with a range of alcohols.
Xantphos的钌配合物已被证明是将活性亚甲基化合物与多种醇进行烷基化的良好催化剂。
Ruthenium xantphos complexes in hydrogen transfer processes: reactivity and mechanistic studies
作者:Araminta E. W. Ledger、Paul A. Slatford、John P. Lowe、Mary F. Mahon、Michael K. Whittlesey、Jonathan M. J. Williams
DOI:10.1039/b813543f
日期:——
The in situ combination of [Ru(PPh3)3(CO)H2] with xantphos is catalytically active for the alkylation of alcohols with the ketonitriletBuC(O)CH2CN in a model oxidation–Knoevenagel–reduction process. The precursor complex [Ru(xantphos)(PPh3)(CO)H2] was isolated and reacted with stoichiometric amounts of PhCH2OH and PhCHO. Under these conditions, the alcohol is decarbonylated to afford [Ru(xantphos)(CO)2H2] and finally [Ru(xantphos)(CO)3], both of which prove to be less active for catalysis than the starting complex. The reactivity of the xantphos system contrasts with that of [Ru(dppp)(PPh3)(CO)H2], which is catalytically inactive for the Knoevenagel reaction and fails to show any stoichiometric reactivity with alcohols.
highly efficient electrophilic cyanation of boron enolates using readily available cyanating reagents, N‐cyano‐N‐phenyl‐p‐toluenesulfonamide (NCTS) and p‐toluenesulfonyl cyanide (TsCN), is reported. Various β‐ketonitriles were prepared by this new protocol, which has a remarkably broad substrate scope compared to existing methods. The present method also allowed efficient synthesis of β‐ketonitriles containing
Direct amino acid-catalyzed cascade reductive alkylation of arylacetonitriles: high-yielding synthesis of ibuprofen analogs
作者:Dhevalapally B. Ramachary、M. Shiva Prasad
DOI:10.1016/j.tetlet.2010.07.131
日期:2010.10
A novel approach for a one-pot, three-component reductivealkylation (TCRA) reaction of arylacetonitriles-containing electron-withdrawing groups with aldehydes/ketones and 1,4-dihydropyridine via iminium-catalysis has been developed. Many TCRA reaction products have direct applications in agricultural and pharmaceutical chemistry.