The zinc–mediated aqueous Barbier–Grignardreaction of cyclic allylic bromide substrates with various aldehydes and ketones to afford homoallylic alcohols was investigated. Aromatic aldehydes and ketones afforded adducts in good yields (66–90%) and with good diastereoselectivities. Non–aromatic aldehydes also reacted well under these conditions, but only poor yields were obtained with non–aromatic
Asymmetric allylation of aryl aldehydes: studies on the scope and mechanism of the palladium catalysed diethylzinc mediated umpolung using phosphoramidite ligands
作者:Gareth P. Howell、Adriaan J. Minnaard、Ben L. Feringa
DOI:10.1039/b518165h
日期:——
Using modular, monodentate phosphoramidite ligands, enantioselective palladium catalysed diethylzinc mediated allylation of aldehydes was achieved. The scope of the asymmetric C–C bond formation was investigated with respect to nucleophilic and electrophilic components and an alternative reaction mechanism is proposed based on our findings.
Active Antimony Mediated Reaction of<i>3</i>-Bromocyclohexene with Aldehydes
作者:Qi-Hui Jin、Ping-Da Ren、Yu-Qiong Li、Zi-Peng Yao
DOI:10.1080/00397919809458694
日期:1998.11
Active antimony in situ from reduction of SbCl3 by Zn powder mediated reaction of 3-bromocyclohexene with aldehydes. The reaction has high chemo- and good stereo- selectivity.