Reductive coupling of (azulen-1-yl)carbonyl compounds by low-valent titanium; pinacol/pinacolone rearrangement versus pinacol and alkene generation
作者:Alexandru C. Razus、Eugenia Andreea Dragu、Simona Nica、Alina Nicolescu
DOI:10.1016/j.tetlet.2011.02.022
日期:2011.4
group strongly influences the course of the TiCl4–Zn promoted McMurry coupling of 1-acetylazulene which afforded, along with the normal coupling products, pinacol 2dl and alkene 3, the pinacolone 4. The latter was likely formed via rearrangement of the pinacolate intermediate. An improved, microwave-assisted protocol was developed for this reaction that provided high yields of products in a short reaction
Absolute Configuration Determination of Azulenyl Diols Isolated From Asymmetric Pinacol Coupling
作者:Eugenia Andreea Dragu、Jean-Valere Naubron、Anamaria Hanganu、Alexandru C. Razus、Simona Nica
DOI:10.1002/chir.22523
日期:2015.11
approach for the pinacolcoupling of 1‐acetylazulene involving easily accessible (R)‐ or (S)‐BINOLs as chiral additive is reported. This supposes the preformation of the chiral titanium–BINOL complex in 1:2 ratio and subsequent reduction with zinc when, 2,3‐di(azulen‐1‐yl)butane‐2,3‐diol can be isolated in around 60% enantiomeric excess. The absoluteconfiguration of the isolated enantiomers was assigned