title: Chemo- and regioselective C(sp³)-H arylation of unactivated allylarenes by deprotonative cross-coupling.
abstract: The combination of aryl bromides, allylbenzene, base and a palladium catalyst usually results in a Heck reaction. Herein we combine these same reagents, but override the Heck pathway by employing a strong base. In the presence of LiN(SiMe3)2, allylbenzene derivatives undergo reversible deprotonation. Transmetalation of the resulting allyllithium intermediate to LPdAr(Br) and reductive elimination provide the 1,1-diarylprop-2-enes, which are not accessible by the Heck reaction. The regioselectivity in this deprotonative cross-coupling process is catalyst-controlled and very high.
authors.affiliation: Department of Chemistry, University of Pennsylvania, 231 S. 34th St. Philadelphia, PA 19104 (USA) http://titanium.chem.upenn.edu/walsh/index.html.
authors.forename: Nusrah
authors.initials: N
authors.lastname: Hussain
authors.forename: Gustavo
authors.initials: G
authors.lastname: Frensch
authors.forename: Jiadi
authors.initials: J
authors.lastname: Zhang
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Walsh
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D010165:Palladium
keywords: CH functionalization; chemoselectivity; deprotonative cross-coupling; palladium catalysis; regioselectivity