Readily available phosphine–imine ligands from α-phenylethylamine for highly efficient Pd-catalyzed asymmetric allylic alkylation

✍ Scribed by Jia-Di Huang; Xiang-Ping Hu; Sai-Bo Yu; Jun Deng; Dao-Yong Wang; Zheng-Chao Duan; Zhuo Zheng

• Book ID: 104057188
• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 243 KB
• Volume: 270
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/j.molcata.2007.01.010

✦ Synopsis

A series of novel chiral phosphine-imine ligands have been prepared by a two-step transformation from chiral ␣-phenylethylamine. The resulting chiral ligands were found to be effective for the palladium-catalyzed asymmetric allylic alkylation of 1,3-diphenylprop-2-en-1-yl pivalate with dimethyl malonate, in which up to 94% ee and 99% conversions were obtained. The results demonstrate that the chirality resided on the chelate ring of P-Pd-N complex is more effective for the transfer of the stereochemical information by comparison with the result obtained by Hashimoto and coworkers' phosphine-imine ligand, in which the chirality lay in the outside of P-Pd-N chelate ring. The effect of solvent, base and substitutent in phosphine-imine ligand on this catalytic reaction is also described.