84993-37-3Relevant academic research and scientific papers
Enantioselective Synthesis of α-Amidoboronates Catalyzed by Planar-Chiral NHC-Cu(I) Complexes
Schwamb, C. Benjamin,Fitzpatrick, Keegan P.,Brueckner, Alexander C.,Richardson, H. Camille,Cheong, Paul H.-Y.,Scheidt, Karl A.
supporting information, p. 10644 - 10648 (2018/09/06)
The first highly selective catalytic hydroboration of alkyl-substituted aldimines to provide medicinally relevant α-amidoboronates is disclosed. The Cu(I)-catalyzed borylation proceeds with excellent facial selectivity when a set of planar-chiral N-heterocyclic carbenes (NHCs) were employed as ligands. Density functional theory computations suggest that interactions between BPin and the planar-chiral catalyst are responsible for the observed stereoselectivity. Important pharmacophores, such as the boronate analogue of isoleucine, can be prepared using a chromatography-free protocol starting from commercially available reagents. The application of these NHC ligands in these Cu(I)-catalyzed processes offers a significant contribution to existing strategies for laboratory-scale preparation of enantioenriched α-amidoboronates.
Asymmetric allylboration of acyl imines catalyzed by chiral diols
Lou, Sha,Moquist, Philip N.,Schaus, Scott E.
, p. 15398 - 15404 (2008/09/18)
Chiral BINOL-derived diols catalyze the enantioselective asymmetric allylboration of acyl imines. The reaction requires 15 mol % (S)-3,3′-Ph2-BINOL as the catalyst and allyldiisopropoxyborane as the nucleophile. The reaction products are obtained in good yields (75-94%) and high enantiomeric ratios (95:5-99.5:0.5) for aromatic and aliphatic imines. High diastereoselectivities (diastereomeric ratio > 98:2) and enantioselectivities (enantiomeric ratio > 98:2) are obtained in the reactions of acyl imines with crotyldiisopropoxyboranes. This asymmetric transformation is directly applied to the synthesis of Maraviroc, the selective CCR5 antagonist with potent activity against HIV-1 infection. Mechanistic investigations of the allylboration reaction including IR, NMR, and mass spectrometry studies indicate that acyclic boronates are activated by chiral diols via exchange of one of the boronate alkoxy groups with activation of the acyl imine via hydrogen bonding.
A NEW GENERAL METHOD OF α-AMIDO-ALKYLATION
Morton, J.,Rahim, A.,Walker, E. R. H.
, p. 4123 - 4126 (2007/10/02)
N-(1-p-Toluenesulphonyl-alkyl) amides, which are readily prepared from an aldehyde, an amide and sodium p-toluenesulphinate, are versatile α-amido-alkylating agents for sulphur nitrogen and carbon nucleophiles.
