Proline‐Catalyzed Asymmetric Formal α‐Alkylation of Aldehydes via Vinylogous Iminium Ion Intermediates Generated from Arylsulfonyl Indoles
2008; Wiley; Volume: 47; Issue: 45 Linguagem: Inglês
10.1002/anie.200803947
ISSN1521-3773
AutoresRafik Rajjak Shaikh, Andrea Mazzanti, Marino Petrini, Giuseppe Bartoli, Paolo Melchiorre,
Tópico(s)Synthesis and Catalytic Reactions
ResumoProline strikes again: The intermolecular enamine-catalyzed asymmetric "formal" α-alkylation of aldehydes is described. Alkylating reagent 1 generates a highly stabilized carbocation, which can readily intercept the enamine intermediate. L-Proline proved to be the best catalyst, providing an easy route to relevant 3-indolyl derivatives 2 with high diastereo- and enantiocontrol.
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