title: Organic chemistry. Functionalization of C(sp3)-H bonds using a transient directing group.
abstract: Proximity-driven metalation has been extensively exploited to achieve reactivity and selectivity in carbon-hydrogen (C-H) bond activation. Despite the substantial improvement in developing more efficient and practical directing groups, their stoichiometric installation and removal limit efficiency and, often, applicability as well. Here we report the development of an amino acid reagent that reversibly reacts with aldehydes and ketones in situ via imine formation to serve as a transient directing group for activation of inert C-H bonds. Arylation of a wide range of aldehydes and ketones at the β or γ positions proceeds in the presence of a palladium catalyst and a catalytic amount of amino acid. The feasibility of achieving enantioselective C-H activation reactions using a chiral amino acid as the transient directing group is also demonstrated.
authors.affiliation: The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Fang-Lin
authors.initials: FL
authors.lastname: Zhang
authors.affiliation: The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Hong
authors.affiliation: The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Tuan-Jie
authors.initials: TJ
authors.lastname: Li
authors.affiliation: The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Hojoon
authors.initials: H
authors.lastname: Park
authors.affiliation: The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA. yu200@scripps.edu.
authors.forename: Jin-Quan
authors.initials: JQ
authors.lastname: Yu
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