title: Iridium Catalyzed Hydro-hydroxyalkylation of Butadiene: Carbonyl Crotylation.
abstract: Exposure of alcohols 1a-1i to butadiene in the presence of a cyclometallated iridium catalyzed derived from allyl acetate, 4-methoxy-3-nitrobenzoic acid and BIPHEP (2,2'-bis(diphenylphosphino)biphenyl) results in hydrogen transfer to generate aldehyde-allyliridium pairs, which engage in C-C coupling to form products of carbonyl crotylation. Under related conditions using 1,4-butanediol as hydrogen donor, butadiene reductively couples to aldehydes 2e-2g and 2i to furnish carbonyl crotylation products 3e-3g and 3i. Thus, butadiene mediated carbonyl crotylation occurs with equal facility from the alcohol or aldehyde oxidation level with complete levels of branched regioselectivity.
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX 78712, USA, ; mkrische@mail.utexas.edu.
authors.forename: Jason R
authors.initials: JR
authors.lastname: Zbieg
authors.forename: Takeo
authors.initials: T
authors.lastname: Fukuzumi
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Krische