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.
Beilstein J Org Chem. 2013 Apr 30;9:832-7. doi: 10.3762/bjoc.9.95. Print 2013.
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.
新型手性 (S,E)-γ-N,N-二苄基硝基烯 2a-c 可由天然 L-(α)-氨基酸经五步反应以 68-88%的总产率合成。2a-c 与氢化物、甲氧基化物、硝酮和叠氮化物亲核试剂的共轭加成反应得到相应的手性 1,3-硝基胺,产率为 74-90%。氰化物阴离子与 2a,b 的共轭加成反应后,通过 HNO2 消除反应得到手性氨基丙烯腈(73-98%)。另一方面,叠氮阴离子与 2a 在乙腈中通过失去 HNO2 的 [3 + 2]-环加成反应反应,提供相应的 1,2,3-三唑衍生物。1,3-硝基胺衍生物 9a,b 的直接还原反应以良好的产率得到相应的 1,3-二胺。