The asymmetric aziridination of cyclicenones with N-tosyloxycarbamates, using N-neopentyl 1,2-diphenylethylenediamine as a catalyst, and its application to the formal total synthesis of (−)-agelastatin A, using a one-pot silylation-selenylation procedure and the regioselective aziridine-opening by an azide anion as key steps, are described.
De Novo Synthesis of Troc-Protected Amines: Intermolecular Rhodium-Catalyzed C−H Amination with <i>N</i>-Tosyloxycarbamates
作者:Hélène Lebel、Kim Huard
DOI:10.1021/ol062953t
日期:2007.2.1
intermolecular C-Hinsertion of the nitrene derived from 2,2,2-trichloroethyl-N-tosyloxycarbamate proceeded in good to excellent yields to produce a variety of Troc-protected amines. With cyclic aliphatic alkanes, it is possible to use only 2 equiv of substrate, whereas the reaction with aromatic alkanes is run neat. Not only does the nitrene insertion proceed in benzylic, secondary, and tertiary C-H bonds
<i>N</i>‐Tosyloxycarbamates as Reagents in Rhodium‐Catalyzed CH Amination Reactions
作者:Kim Huard、Hélène Lebel
DOI:10.1002/chem.200702027
日期:2008.7.7
nitrenes for use in C-Hinsertion reactions were obtained from N-tosyloxycarbamates in the presence of an inorganic base and a rhodium(II) dimer complex catalyst. The C-H amination reaction proceeds smoothly, and the potassium tosylate that forms as a byproduct is easily removed by filtration or an aqueous workup. This new methodology allows the amination of ethereal, benzylic, tertiary, secondary
Asymmetric Catalytic Aziridination of Cyclic Enones
作者:Francesco De Vincentiis、Giorgio Bencivenni、Fabio Pesciaioli、Andrea Mazzanti、Giuseppe Bartoli、Patrizia Galzerano、Paolo Melchiorre
DOI:10.1002/asia.201000040
日期:——
The first catalytic method for the asymmetricaziridination of cyclic enones is described. The presented organocatalytic strategy is based on the use of an easily available organocatalyst that is able to convert a wide range of cyclic enones into the desired aziridines with very high enantiomeric purity and good chemical yield. Such a method may very well open up new opportunities to stereoselectively
The [4+1] cycloaddition reaction of bifunctional amino reagents has been achieved with in situ formed aza‐ortho‐quinonemethides. Specifically, N‐(tosyloxy)carbamates were used as an N1 synthon and bifunctional amino reagents for this transformation, which provides a metal‐free, catalyst‐free, and oxidant‐free strategy to form nitrogen‐nitrogen bonds.