title: Amino-zinc-ene-enolate cyclization: a short access to cis-3-substituted prolino-homotryptophane derivatives.
abstract: Proline chimeras are useful tools for medicinal chemistry and/or biological applications. The asymmetric synthesis of cis-3-substituted prolines can be easily achieved via amino-zinc-ene-enolate cyclization followed by transmetalation of the cyclic zinc intermediate for further functionalization. Syntheses of prolino-homotryptophane derivatives were achieved through Negishi cross-coupling of the zinc intermediate with indole rings. The use of Pd catalyst derived from Fu's [(t-Bu3)PH]-BF4 was required to avoid the undesired beta-hydride elimination. Optically pure and orthogonally protected compounds were obtained readily usable for peptide synthesis.
authors.affiliation: UPMC Univ Paris 06, UMR 7613 and FR2769, Synthèse, Structure et Fonction de Molécules Bioactives, Fédération de Chimie Moléculaire, UPMC, 4, Place Jussieu, 75252, Paris Cedex 05, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Mothes
authors.forename: Solange
authors.initials: S
authors.lastname: Lavielle
authors.forename: Philippe
authors.initials: P
authors.lastname: Karoyan
mesh_terms: D000588:Amines / Q000737:chemistry*; D001881:Borates / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D007211:Indoles / Q000737:chemistry; D008956:Models, Chemical; D010165:Palladium / Q000737:chemistry; D011392:Proline / Q000031:analogs & derivatives / Q000138:chemical synthesis*; D013237:Stereoisomerism; D014364:Tryptophan / Q000031:analogs & derivatives / Q000138:chemical synthesis*; D015032:Zinc / Q000737:chemistry*
chemical_list: D000588:Amines; D001881:Borates; D007211:Indoles; D010165:Palladium; D014364:Tryptophan; D011392:Proline; D015032:Zinc