title: Efficient alkyl ether synthesis via palladium-catalyzed, picolinamide-directed alkoxylation of unactivated C(sp3)-H and C(sp2)-H bonds at remote positions.
abstract: We report the efficient synthesis of alkyl ethers by the functionalization of unactivated sp(3)- and sp(2)-hybridized C-H bonds. In the Pd(OAc)(2)-catalyzed, PhI(OAc)(2)-mediated reaction system, picolinamide-protected amine substrates undergo facile alkoxylation at the γ or δ positions with a range of alcohols, including t-BuOH, to give alkoxylated products. This method features a relatively broad substrate scope for amines and alcohols, inexpensive reagents, and convenient operating conditions. This method highlights the emerging value of unactivated C-H bonds, particularly the C(sp(3))-H bond of methyl groups, as functional groups in organic synthesis.
authors.affiliation: Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: Shu-Yu
authors.initials: SY
authors.lastname: Zhang
authors.forename: Gang
authors.initials: G
authors.lastname: He
authors.forename: Yingsheng
authors.initials: Y
authors.lastname: Zhao
authors.forename: Kiwan
authors.initials: K
authors.lastname: Wright
authors.forename: William A
authors.initials: WA
authors.lastname: Nack
authors.forename: Gong
authors.initials: G
authors.lastname: Chen