title: anti-Aminoallylation of aldehydes via ruthenium-catalyzed transfer hydrogenative coupling of sulfonamido allenes: 1,2-aminoalcohols.
abstract: Ruthenium-catalyzed transfer hydrogenation of N-sulfonamido allene 1e in the presence of aromatic aldehydes 2a-f, alpha,beta-unsaturated aldehydes 2g-i, and aliphatic aldehydes 2j-l results in reductive coupling to furnish the corresponding anti-aminoallylation products 3a-l. Reductive coupling of allenamide 1e to aldehyde 2a conducted using 2-propanol-d(8) as the terminal reductant delivers deuterio-3a. The observed pattern of deuterium incorporation suggests reversible allene hydrometalation with incomplete regioselectivity in advance of carbonyl addition. A survey of monosubstituted allenes 1f-i was conducted. High levels of anti-diastereoselectivity were observed only when tert-butyl allene 1f was used. This protocol represents an alternative to the use of amino-substituted allylborane reagents in carbonyl aminoallylation and avoids the use of stoichiometric metallic reagents.
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Eduardas
authors.initials: E
authors.lastname: Skucas
authors.forename: Jason R
authors.initials: JR
authors.lastname: Zbieg
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Krische