Enantioselective copper-catalyzed allylic alkylation with dialkylzincs using phosphoramidite ligands.
[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.
Malda
H
H
Department of Organic and Molecular Inorganic Chemistry, Stratingh Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
van Zijl
A W
AW
Arnold
L A
LA
Feringa
B L
BL
D000477:Alkylating Agents; D003300:Copper / Q000737:chemistry*; D008024:Ligands; D008956:Models, Chemical; D009943:Organophosphorus Compounds / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors; D015032:Zinc / Q000737:chemistry*
D000477:Alkylating Agents; D008024:Ligands; D009943:Organophosphorus Compounds; D003300:Copper; D015032:Zinc