Enantioselective cycloadditions of 2-alkenoylpyridine-N-oxides catalysed by a bis(oxazoline)/Cu(II) complex: structure of the reactive intermediate |
| |
Authors: | Livieri Alessandro Boiocchi Massimo Desimoni Giovanni Faita Giuseppe |
| |
Institution: | Department of Organic Chemistry, University of Pavia, V.le Taramelli, 10, 27100 Pavia, Italy. |
| |
Abstract: | Diels–Alder and 1,3‐dipolar cycloadditions involving (E)‐3‐aryl‐1‐(pyridin‐2‐yl‐N‐oxide)prop‐2‐en‐1‐ones as the 2π components are efficiently catalysed by bis(oxazoline)–CuII complexes. The cycloadducts are obtained in quantitative yields with up to 98 % ee; absolute configurations were determined by X‐ray analysis. The structure of the reactive complex, determined by X‐ray analysis, is fully consistent with the stereochemical outcome of the catalysed process (approach of the diene or nitrone to the less hindered face of the coordinated pyridine‐N‐oxide derivative). |
| |
Keywords: | asymmetric catalysis copper cycloaddition nitrogen heterocycles |
本文献已被 PubMed 等数据库收录! |
|