title: A convenient allenoate-based synthesis of 2-quinolin-2-yl malonates and β-ketoesters.
abstract: N-Protected o-aminobenzaldehydes smoothly react with α,γ-dialkylallenoates under Brønsted basic conditions to yield 2,3-disubstituted quinolines. This three-step reaction cascade of Michael addition, aldol condensation, and 1,3-N → C rearrangement uses the complete protecting group as a building block in a highly efficient C,C-bond formation of a new all-carbon quaternary center. Carbamate protected substrates (N-Boc, N-Cbz, N-Alloc) thus give 2-quinolin-2-yl-malonates, while amide protected substrates (N-Ac, N-Bz) afford 2-quinolin-2-yl-β-ketoesters in high yields.
authors.affiliation: Institute of Organic Chemistry, RWTH Aachen University , Landoltweg 1, 52074 Aachen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Selig
authors.forename: William
authors.initials: W
authors.lastname: Raven
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D004952:Esters; D008314:Malonates / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D011804:Quinolines / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D004952:Esters; D008314:Malonates; D011804:Quinolines; C116609:3-hydroxybutanal