Design and Development of Cyclohexane-Based P,N-Ligands for Transition Metal Catalysis
摘要:
[GRAPHICS]A new class of cyclohexane-based P,N-ligands is readily obtained through aziridine ring opening with suitable phosphorus nucleophiles under acidic conditions. trans-1-Amino-2-diphenylphosphinocyclohexane is resolved with tartaric acid to give the final product in >99% ee. The new ligands show high stability toward oxidation at the phosphorus atom.
Enantioselective Cu(II)-catalyzed Henry reactions with chiral cyclohexane-based amidophosphine ligands
摘要:
Copper-catalyzed asymmetric Henry reactions are described. Using a new chiral amidophosphine ligand, the Henry reaction of nitromethane and various aldehydes proceeded smoothly to provide chiral beta-nitroalcohols in reasonable yields (up to 98%) with high enantioselectivity (up to 97% ee). (C) 2016 Elsevier Ltd. All rights reserved.
New ureas containing glycosyl and diphenylphosphinyl scaffolds: synthesis and the first attempts to use them in asymmetric synthesis
作者:Stanisław Porwański
DOI:10.1016/j.carres.2014.04.015
日期:2014.7
Chiral ureas containing glycosyl and diphenylphosphinyl scaffolds were found to be an effective organocatalyst. They were synthesised in high yields by a one-pot tandem Staudinger/aza-Wittig coupling reaction. The first attempts of using them in asymmetric synthesis are presented. Yields of the Morita-Baylis-Hillman reaction were moderate with an enantiomeric excess of up to 80%.
Enantioselective aza-Morita–Baylis–Hillman reaction between acrylates and N-Boc isatin ketimines: asymmetric construction of chiral 3-substituted-3-aminooxindoles
The first enantioselective aza-MoritaâBaylisâHillman reaction of acrylates with ketimines derived from isatins has been developed. With 2 mol% of chiral bifunctional phosphine-squaramide 4e, optically active 3-substituted-3-amino-2-oxindoles were obtained in excellent yields with up to 91% ee.
A class of bifunctional phosphinothioureas derived from saccharide was developed as new organocatalysts for the enantioselective Morita‐Baylis‐Hillman reaction between acrylates and aldehydes. With 10 mol% of glucose‐based phosphinothiourea 1d, the allylic alcohols were obtained in up to 96% yield and 83% ee under mild reaction conditions.
Bifunctional (Thio)urea–Phosphine Organocatalysts Derived from d-Glucose and α-Amino Acids and Their Application to the Enantioselective Morita–Baylis–Hillman Reaction
Novel (thio)urea–tertiary phosphines were developed for use as bifunctional organocatalysts readily available from naturally occurring molecules: saccharides and amino acids. The efficiency of the organocatalysts was demonstrated in the asymmetricMorita–Baylis–Hillman (MBH) reaction of aromatic aldehydes with acrylates. The MBH products were obtained in good yields (up to 85%) and with high enantioselectivities
Au(III) complexes with tetradentate-cyclam-based ligands
作者:Ann Christin Reiersølmoen、Thomas N Solvi、Anne Fiksdahl
DOI:10.3762/bjoc.17.18
日期:——
give moderate to excellent yields (50–96%) of the corresponding novel tetra-coordinated N,N,N,N-Au(III) complexes with alternating five- and six-membered chelate rings. The testing of the catalytic ability of the cyclam-based N,N,N,N-Au(III) complexes demonstrated high catalytic activity of some complexes in selected test reactions (full conversion in 1–24 h, 62–97% product yields).