title: Diastereoselective synthesis of 4,5'-bis-proline compounds via reductive dimerization of N-acyloxyiminium ions.
abstract: A short, practical synthesis of novel, unsymmetrical 4,5'-bis-proline compounds has been achieved, highlighted by the application of an unprecedented samarium diiodide-driven regio- and diastereocontrolled reductive dimerization of N-acyloxyiminium ions generated from readily available 2-methoxy-5-silyloxymethyl-N-Boc pyrrolidines. The title proline dimers proved to be pertinent metal-free catalysts in aldol and Mannich reactions.
authors.affiliation: Dipartimento Farmaceutico, Università degli Studi di Parma, Viale G.P. Usberti 27A, I-43100 Parma, Italy.
authors.forename: Franca
authors.initials: F
authors.lastname: Zanardi
authors.forename: Andrea
authors.initials: A
authors.lastname: Sartori
authors.forename: Claudio
authors.initials: C
authors.lastname: Curti
authors.forename: Lucia
authors.initials: L
authors.lastname: Battistini
authors.forename: Gloria
authors.initials: G
authors.lastname: Rassu
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Nicastro
authors.forename: Giovanni
authors.initials: G
authors.lastname: Casiraghi
mesh_terms: D002384:Catalysis; D007097:Imines / Q000737:chemistry*; D008352:Mannich Bases / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D011392:Proline / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D012493:Samarium / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared; D013237:Stereoisomerism
chemical_list: D007097:Imines; D008352:Mannich Bases; D012493:Samarium; D011392:Proline