A new homogeneous support has been developed that is based on a fructose-derived ionic liquid. It has been applied to the preparation of a series of supported Diels-Alder adducts. The cleavage of these adducts from the ionic liquid has resulted in some interesting observations regarding the base stability of imidazolium cations. Using a transesterification cleavage, the ionic support can be recovered and recycled. (C) 2003 Published by Elsevier Ltd.
New and Facile Synthesis of Aminobicyclo[2.2.1]heptane-2-carboxylic Acids
作者:Seung-Yong Seo、Dongyun Shin、Taek-Soo Kim
DOI:10.1055/s-0034-1378690
日期:——
b-2-aminobicyclo[2.2.1]heptane-2-carboxylic acid is described. Substrate-controlled α-carboxylation of norbonene monoester delivered the asymmetric diester intermediate with high diastereoselectivity (up to 35:1). Sequential chemoselective ester cleavage, Curtius rearrangement, and hydrolysis gave the a- and b-isomers of 2-aminobicyclo[2.2.1]heptane-2-carboxylic acid, respectively.
Closing the Cycle as It Begins: Synthesis of
<i>ortho</i>
‐Iodobiaryls via Catellani Reaction
作者:Vinayak Botla、Marco Fontana、Aleksandr Voronov、Raimondo Maggi、Elena Motti、Giovanni Maestri、Nicola Della Ca'
DOI:10.1002/anie.202218928
日期:——
A new strategy based on the Catellanireactions has enabled the one-pot synthesis of ortho-iodobiaryls starting from aryl iodides and bromides. Beyond the synthetic utility of this transformation (32 examples and 6 subsequent derivatizations), a DFT study provides insights on the mechanism of the reductive elimination step, which is driven by an original transmetallation between palladium(II)-halide