154077-75-5Relevant articles and documents
Enantioselective cyclopropanation of conjugated cyanosulfones using carbohydrate-based crown ether catalysts
Nemcsok, Tamás,Rapi, Zsolt,Bagi, Péter,Guan, Ying Hou,Orbán, István,Keglevich, Gy?rgy,Bakó, Péter
, (2020)
A few new D-galactose- and D-glucose-based monoaza-15-crown-5 type lariat ethers have been synthesized. These macrocycles and their derivatives proved to be efficient catalysts in the cyclopropanation of (E)-3-phenyl-2-(phenylsulfonyl)acrylonitrile performed with diethyl bromomalonate under mild phase transfer conditions. Among the catalysts tested, the macrocycle having methyl α-D-galactopyranoside unit generated the highest asymmetric induction (80% ee). In the reactions of the aryl-substituted phenylsulfonyl-acrylonitrile derivatives, the cyclopropanation of the meta- and para-substituted starting materials took place with high ee values (75–84% ee). The cyclopropane derivatives synthesized from analogous α,β-unsaturated cyanosulfones containing naphthyl, pyridyl, furyl and thienyl groups were obtained with enantioselectivities up to 85%, and in excellent yields.
Mild and efficient direct aromatic iodination
Johnsson, Richard,Meijer, Andréas,Ellervik, Ulf
, p. 11657 - 11663 (2007/10/03)
Aryl iodides are important synthetic intermediates that can be transformed into tritium labelled compounds by metal-mediated hydrodehalogenation and also react in a number of important synthetic transformations. We present ICl/In(OTf)3 as a new reagent combination for mild iodination, suitable for acid-sensitive substrates such as carbohydrates.
