Continuous Flow Acylation of (Hetero)aryllithiums with Polyfunctional N,N-Dimethylamides and Tetramethylurea in Toluene

Djukanovic, Dimitrije; Heinz, Benjamin; Mandrelli, Francesca; Mostarda, Serena; Filipponi, Paolo; Martin, Benjamin und Knochel, Paul (2021): Continuous Flow Acylation of (Hetero)aryllithiums with Polyfunctional N,N-Dimethylamides and Tetramethylurea in Toluene. In: Chemistry-A European Journal, Bd. 27, Nr. 56: S. 13977-13981

Abstract

The continuous flow reaction of various aryl or heteroaryl bromides in toluene in the presence of THF (1.0 equiv) with sec-BuLi (1.1 equiv) provided at 25 degrees C within 40 sec the corresponding aryllithiums which were acylated with various functionalized N,N-dimethylamides including easily enolizable amides at -20 degrees C within 27 sec, producing highly functionalized ketones in 48-90 % yield (36 examples). This method was well suited for the preparation of alpha-chiral ketones such as naproxene and ibuprofen derived ketones with 99 % ee. A one-pot stepwise bis-addition of two different lithium organometallics to 1,1,3,3-tetramethyurea (TMU) provided unsymmetrical ketones in 69-79 % yield (9 examples).

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Chemie und Pharmazie > Department Chemie
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie
• ISSN: 0947-6539
• Sprache: Englisch