(Tosylimino)phenyl-λ<sup>3</sup>-iodane as a Reagent for the Synthesis of Methyl Carbamates via Hofmann Rearrangement of Aromatic and Aliphatic Carboxamides
作者:Akira Yoshimura、Matthew W. Luedtke、Viktor V. Zhdankin
DOI:10.1021/jo300007c
日期:2012.2.17
A new, mild procedure for the Hofmann rearrangement of aromatic and aliphatic carboxamides using (tosylimino)phenyl-λ3-iodane, PhINTs, as a reagent is reported. Because of the mild reaction conditions, this method is particularly useful for the Hofmann rearrangement of substituted benzamides, which usually afford complex reaction mixtures with other hypervalent iodine oxidants. The mild reaction conditions
Electrochemically induced Hofmannrearrangement under new solvent systems containing a variety of alcohols was developed. Since the reaction proceeds under mild conditions (neutral), a variety of carbamates possessing various alkoxy moieties could be easily prepared by this method. An epoxy functional group in the amide and alcohol parts remained intact during the electrolysis.
Hofmann Rearrangement of Carboxamides Mediated by Hypervalent Iodine Species Generated in Situ from Iodobenzene and Oxone: Reaction Scope and Limitations
作者:Aleksandra A. Zagulyaeva、Christopher T. Banek、Mekhman S. Yusubov、Viktor V. Zhdankin
DOI:10.1021/ol101993q
日期:2010.10.15
Alkylcarboxamides can be converted to the respective amines by Hofmann rearrangement using hypervalent iodine species generated in situ from PhI and Oxone in aqueous acetonitrile. On the basis of this reaction, a convenient experimental procedure for the preparation of alkylcarbamates using Oxone as the oxidant in the presence of iodobenzene in methanol has been developed. An efficient method for direct
Preparation of Methyl <i>N</i>‐Substituted Carbamates from Amides through <i>N</i>‐Chloroamides
作者:Gene A. Hiegel、Tyrone J. Hogenauer
DOI:10.1081/scc-200066695
日期:2005.8.1
Abstract Amides are chlorinated on the nitrogen using trichloroisocyanuric acid, and the N‐chloroamides are then rearranged to the corresponding methyl N‐substituted carbamates by sodium methoxide in methanol.
This procedure offers an easy access to various protected amines or diamines, which represent important synthetic precursors. An efficient, one-pot procedure for the Hofmann rearrangement of aromatic and aliphatic amides has been developed. Methyl and benzyl carbamates are produced with N-bromoacetamide in the presence of lithium hydroxide or lithium methoxide, in high yields. β-Phenylamino amides gave