title: Synthesis of diamino carboxylic esters by palladium-catalyzed oxidative intramolecular diamination of acrylates.
abstract: Unligated palladium(II) salts catalyze the oxidative diamination of acrylic esters to yield 2,3-diamino carboxylic esters. The reaction employs copper(II) bromide as oxidant and proceeds with good to excellent stereoselectivities and complete chemoselectivity. Preliminary mechanistic studies provide evidence for the involvement of a direct amination of the C--Pd bond in the alpha position relative to the ester group. This protocol significantly broadens the overall scope of the palladium-catalyzed diamination of alkenes and represents the first direct diamination of functionalized nonterminal substrates. The reaction yields readily protected 2,3-diamino acid derivatives, which can be considered as highly functionalized building blocks for subsequent synthesis. The use of one of these new diamination products as a suitable starting material in a short synthesis of the alkaloid absouline is demonstrated as an example.
authors.affiliation: Institut de Chimie, UMR 7177, Université Louis Pasteur, France. muniz@chimie.u-strasbg.fr
authors.forename: Kilian
authors.initials: K
authors.lastname: Muñiz
authors.forename: Jan
authors.initials: J
authors.lastname: Streuff
authors.forename: Patricia
authors.initials: P
authors.lastname: Chávez
authors.forename: Claas H
authors.initials: CH
authors.lastname: Hövelmann