Malda H, van Zijl A W, Arnold L A, Feringa B L
Department of Organic and Molecular Inorganic Chemistry, Stratingh Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
Org Lett. 2001 Apr 19;3(8):1169-71. doi: 10.1021/ol0156289.
[reaction: see text]. In the presence of a catalytic amount of copper salts, cinnamyl halides undergo a regio- and enantioselective S(N)2' alkylation with dialkylzincs using chiral phosphoramidites as ligands. An S(N)2':S(N)2 ratio of 85:15 and enantiomeric excesses up to 77% for the chiral S(N)2' products are found. Variation of solvent and reaction temperature revealed that the highest regio- and enantioselectivities are found using coordinating solvents of -40 degrees C.