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Espinosa López, Miguel; Blay Llinares, Gonzalo
Perfil; Cardona Prósper, María Luz; Muñoz, M. Carmen; Pedro, José Ramón
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This document is a artículoDate2017
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Unlike their isocyano and isothiocyanato analogues, isocyanato esters remain almost unexplored as formal 1,3-dipoles in asymmetric catalytic reactions. The first asymmetric formal [3+2] cycloaddition involving isocyanato esters and electrophilic alkenes is reported. Diisopropyl 2-isocyanatomalonate reacts with a,b-unsaturated N-(o-anisidyl) imines in the presence of aMg(OTf)2-BOX complex to give highly substituted chiral pyrrolidinones featuring a conjugate exocyclic double bond with excellent yields and enantiomeric excesses up to 99 %. Several transformations of the resulting heterocycles, including the synthesis of a pyroglutamic acid derivative, have been carried out. |
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Espinosa López, Miguel Blay Llinares, Gonzalo Cardona Prósper, María Luz Muñoz, M. Carmen Pedro, José Ramón 2017 Catalytic Asymmetric Formal [3+2] Cycloaddition of 2-Isocyanatomalonate Esters and Unsaturated Imines: Synthesis of Highly Substituted Chiral γ‐Lactams Chemistry-A European Journal 23 14707 14711 |
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https://doi.org/10.1002/chem.201702777
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