title: Phosphoramidite-Cu(OTf)2 complexes as chiral catalysts for 1,3-dipolar cycloaddition of iminoesters and nitroalkenes.
abstract: Chiral complexes formed by phosphoramidites such as (Sa,R,R)-9 and Cu(OTf)2 are excellent catalysts for the general 1,3-dipolar cycloaddition between azomethine ylides and nitroalkenes affording the corresponding tetrasubstituted proline esters mainly as exo-cycloadducts in high er at room temperature. The exo-cycloadducts can be obtained in enantiomerically pure form just after simple recrystallization. DFT calculations support the stereochemical results.
authors.affiliation: Departamento de Química Orgánica e Instituto de Síntesis Orgánica (ISO), Facultad de Ciencias, Universidad de Alicante , 03080-Alicante, Spain, Departmento de Química Orgánica I, Facultad de Química, Universidad del País Vasco , P. K. 1072, E-20018 San Sebastián, Spain, and IKERBASQUE, Basque Foundation for Science , 48011 Bilbao, Spain.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Castelló
authors.forename: Carmen
authors.initials: C
authors.lastname: Nájera
authors.forename: José M
authors.initials: JM
authors.lastname: Sansano
authors.forename: Olatz
authors.initials: O
authors.lastname: Larrañaga
authors.forename: Abel
authors.initials: A
authors.lastname: de Cózar
authors.forename: Fernando P
authors.initials: FP
authors.lastname: Cossío
mesh_terms: D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D061565:Cycloaddition Reaction; D015394:Molecular Structure; D009574:Nitro Compounds / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D056831:Coordination Complexes; D009574:Nitro Compounds; D009943:Organophosphorus Compounds; C434331:phosphoramidite; D003300:Copper