[reaction: see text] tert-Butyl (phenylsulfonyl)alkyl-N-hydroxycarbamates 1 have been easily prepared from aldehydes and tert-butyl N-hydroxycarbamate in a methanol-water mixture using sodium benzenesulfinate and formic acid. These sulfones 1 behave as N-(Boc)-protected nitrones 4 in the reaction with organometallics to give N-(Boc)hydroxylamines. Some chemical transformations showing their interest
Meldrum’sacid has turned out to be a useful ketene equivalent when faced to nitrone dipoles to form various isoxazolidin‐5‐one derivatives under very mild Brønsted base organocatalytic conditions. The first asymmetric version of this original domino anionic formal [3+2] cycloaddition–decarboxylation reaction was demonstrated by means of quinine‐based organocatalysts.
Organocatalytic Asymmetric Synthesis of Chiral Dioxazinanes and Dioxazepanes with <i>in Situ</i> Generated Nitrones via a Tandem Reaction Pathway Using a Cooperative Cation Binding Catalyst
作者:Yidong Liu、Jun Ao、Sushovan Paladhi、Choong Eui Song、Hailong Yan
DOI:10.1021/jacs.6b10660
日期:2016.12.21
pharmaceuticals and biological processes. Cycloaddition reactions are most suitable synthetic tools to efficiently construct chemically diverse sets of heterocycles with great structural complexity owing to the simultaneous or sequential formation of two or more bonds, often with a high degree of selectivity. Herein, we report an unprecedented formal cycloaddition of N-Boc-N-hydroxy amido sulfones as the nitrone