Enantioselective conjugate addition of donor-acceptor hydrazones to α,β-unsaturated aldehydes through formal diaza-ene reaction: access to 1,4-dicarbonyl compounds.
Donor-acceptor monosubstituted hydrazones participate as suitable reagents able to undergo an enantioselective formal diaza-ene reaction with α,β-unsaturated aldehydes under chiral secondary amine catalysis. This constitutes a new approach for the enantioselective conjugate addition of hydrazones to enals under metal-free conditions and leads to the formation of γ-hydrazono carboxylic acids after oxidation/[1,3]-H shift. The methodology is also useful for the synthesis of enantioenriched β-substituted α-keto-1,5-diesters by using the hydrazone moiety as a masked carbonyl group.
Departamento de Química Orgánica II, Facultad de Ciencia y Tecnología, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), P.O. Box 644, E-48080 Bilbao, Spain.
Maitane
M
Fernández
Uxue
U
Uria
Jose L
JL
Vicario
Efraím
E
Reyes
Luisa
L
Carrillo