Chiral γ-nitroaldehydes 1 are easily accessible by the organocatalytic Michael addition of aldehydes to nitroalkenes. In this paper, we report the organocatalytic fluorination of 1 with N-fluorobenzenesulfonimide (NFSI) leading to the highly stereoselective construction of a challenging quaternary fluorinated stereocenter at the α position of α,α-dialkyl aldehydes. The reaction takes place via a chiral trisubstituted enamine, so far rather unexplored in the field of organocatalysis. Fluorinated products 3 are direct precursors of chiral monofluorinated 3,4-polysubstituted pyrrolidines. Mechanistic details are discussed with the aid of computational results.
The Organocatalytic α-Fluorination of Chiral γ-Nitroaldehydes: the Challenge of Facing the Construction of a Quaternary Fluorinated Stereocenter / Emma, Marco Giuseppe; Lombardo, Marco; Trombini, Claudio; Quintavalla, Arianna. - In: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY. - ISSN 1434-193X. - STAMPA. - 2016:19(2016), pp. 3223-3232. [10.1002/ejoc.201600378]
The Organocatalytic α-Fluorination of Chiral γ-Nitroaldehydes: the Challenge of Facing the Construction of a Quaternary Fluorinated Stereocenter
EMMA, MARCO GIUSEPPE;LOMBARDO, MARCO;TROMBINI, CLAUDIO;QUINTAVALLA, ARIANNA
2016
Abstract
Chiral γ-nitroaldehydes 1 are easily accessible by the organocatalytic Michael addition of aldehydes to nitroalkenes. In this paper, we report the organocatalytic fluorination of 1 with N-fluorobenzenesulfonimide (NFSI) leading to the highly stereoselective construction of a challenging quaternary fluorinated stereocenter at the α position of α,α-dialkyl aldehydes. The reaction takes place via a chiral trisubstituted enamine, so far rather unexplored in the field of organocatalysis. Fluorinated products 3 are direct precursors of chiral monofluorinated 3,4-polysubstituted pyrrolidines. Mechanistic details are discussed with the aid of computational results.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.