An asymmetrichydrogenation of hydrazones with a unique nickel catalyst has been developed for the synthesis of chiral hydrazines with up to 99 % yield and 99.4 : 0.6 er and a broad substrate scope. Deuterium labelling experiments indicated that the hydrazone substrates undergo imine-enamine tautomerization in the mixed solvents.
Oxaziridine-Mediated Amination of Primary Amines: Scope and Application to a One-Pot Pyrazole Synthesis
作者:Alan Armstrong、Lyn H. Jones、Jamie D. Knight、Richard D. Kelsey
DOI:10.1021/ol0474507
日期:2005.2.1
Electrophilic amination of primary aliphatic and aromatic amines is reported using a diethylketomalonate-derived oxaziridine to afford the corresponding N-Boc hydrazines in good to excellent yields. The method allows a one-pot synthesis of pyrazoles from primary amines. [Reaction: see text]
Catalytic Enantioselective Hydrogenation of <i>N</i>-Alkoxycarbonyl Hydrazones: A Practical Synthesis of Chiral Hydrazines
作者:Naoki Yoshikawa、Lushi Tan、J. Christopher McWilliams、Deepa Ramasamy、Ruth Sheppard
DOI:10.1021/ol902602c
日期:2010.1.15
An enantioselective hydrogenation of hydrazones catalyzed by Rh complexes (Rh-Josiphos or Rh-Taniaphos) has been developed. The protocol can be applied to hydrazones with three different protective groups (Boc, Cbz, and methoxycarbonyl), allowing for selective deprotection and further elaboration of the hydrazine products in the presence of other functional groups.