Catalytic Asymmetric Inverse-Electron-Demand Diels−Alder Reaction of <i>N</i>-Sulfonyl-1-Aza-1,3-Dienes
作者:Jorge Esquivias、Ramón Gómez Arrayás、Juan C. Carretero
DOI:10.1021/ja0658766
日期:2007.2.1
An efficient chiral Lewis acid-catalyzed inverse-electron-demand Diels−Alderreaction of 1-azadienes is described. This procedure is based on the combination of NiII-DBFOX complex as catalyst and the use of a metal-coordinating (8-quinolyl)sulfonyl moiety at the iminic nitrogen of the N-sulfonyl 1-aza-1,3-diene, providing highly functionalized piperidine derivatives in good yields with excellent endo-selectivity
Copper-Catalyzed Enantioselective Conjugate Addition of Dialkylzinc Reagents to (2-Pyridyl)sulfonyl Imines of Chalcones
作者:Jorge Esquivias、Ramon Gómez Arrayás、Juan C. Carretero
DOI:10.1021/jo0511602
日期:2005.9.1
The enantioselectivecatalytic 1,4-addition to α,β-unsaturated ketimines is an unprecedented process. Herein, we document the copper-catalyzed addition of dialkylzincreagents to (2-pyridylsulfonyl)imines of chalcones. This process occurs rapidly in the presence of a chiral phosphoramidite ligand to afford exclusively the 1,4-addition product. In the case of addition of dimethylzinc, enantioselectivities