New highlyactive ansa-ammonium borate catalysts for the direct metal-freehydrogenation of imines were prepared by tuning of the basicity and steric bulkiness of their amine moieties. The highest catalytic activity among previously reported organocatalytic systems was shown for a wide range of nitrogen-containing substrates. The first example of asymmetric imine hydrogenation based on the ansa-ammonium
Parahydrogen-induced polarization study of imine hydrogenations mediated by a metal-free catalyst
作者:Danila O. Zakharov、Konstantin Chernichenko、Kristina Sorochkina、Timo Repo、Vladimir V. Zhivonitko
DOI:10.1039/d2dt02178a
日期:——
can provide strongly enhanced NMR signals for catalytichydrogenation reaction products and intermediates. Among other matters, this can be employed to study the mechanisms of the corresponding chemical transformations. Commonly, noble metal complexes are used for reactions with parahydrogen. Herein, we present a PHIP study of metal-free imine hydrogenations catalyzed by the ansa-aminoborane catalyst