title: A versatile and efficient approach for the synthesis of chiral 1,3-nitroamines and 1,3-diamines via conjugate addition to new (S,E)-γ-aminated nitroalkenes derived from L-α-amino acids.
abstract: New chiral (S,E)-γ-N,N-dibenzylated nitroalkenes 2a-c were synthesized from natural L-(α)-amino acids in five steps with overall yields of 68-88%. The conjugate addition of hydride, methoxide, nitronate and azide nucleophiles to 2a-c led to the corresponding chiral 1,3-nitroamines in 74-90% yield. The conjugate addition of cyanide anion to 2a,b was followed by HNO2 elimination affording chiral aminated acrylonitriles (73-98%). On the other hand, the azide anion reacted with 2a, in acetonitrile, via a [3 + 2]-cycloaddition in which HNO2 was lost, providing the corresponding 1,2,3-triazole derivative. Direct reduction of 1,3-nitroamine derivatives 9a,b produced the corresponding 1,3-diamines in good yields.
authors.affiliation: Núcleo de Pesquisas de Produtos Naturais, Laboratório de Síntese Estereosseletiva de Substâncias Bioativas, Universidade Federal do Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil.
authors.forename: Vera Lúcia Patrocinio
authors.initials: VL
authors.lastname: Pereira
authors.forename: André Luiz da Silva
authors.initials: AL
authors.lastname: Moura
authors.forename: Daniel Pais Pires
authors.initials: DP
authors.lastname: Vieira
authors.forename: Leandro Lara
authors.initials: LL
authors.lastname: de Carvalho
authors.forename: Eliz Regina Bueno
authors.initials: ER
authors.lastname: Torres
authors.forename: Jeronimo da Silva
authors.initials: Jda S
authors.lastname: Costa
keywords: Baylis–Hillman reaction; Michael addition; amino alcohol; amino aldehyde; azide addition; cyanide addition