180684-58-6Relevant academic research and scientific papers
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
Pereira, Vera Lucia Patrocinio,Da Silva Moura, Andre Luiz,Vieira, Daniel Pais Pires,De Carvalho, Leandro Lara,Torres, Eliz Regina Bueno,Da Silva Costa, Jeronimo
supporting information, p. 832 - 837 (2013/06/05)
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.
Parallel kinetic resolution of acyclic γ-amino-α,β- unsaturated esters: Application to the asymmetric synthesis of 4-aminopyrrolidin-2-ones
Davies, Stephen G.,Lee, James A.,Roberts, Paul M.,Thomson, James E.,Yin, Jingda
supporting information; experimental part, p. 218 - 221 (2012/03/08)
Conjugate addition of a 50:50 pseudoenantiomeric mixture of lithium (R)-N-benzyl-N-(α-methylbenzyl)amide and lithium (S)-N-3,4- dimethoxybenzyl-N-(α-methylbenzyl)amide to a range of racemic acyclic γ-amino-α,β-unsaturated esters (derived from the corresponding α-amino acids) effects their efficient parallel kinetic resolution, allowing the preparation of enantiopure β,γ-diamino esters. The β,γ-diamino ester products of these reactions are readily converted into the corresponding substituted 4-aminopyrrolidin-2-ones via N-debenzylation and cyclization.
Investigation of the configurational stability of lithiated phosphine oxides using the Hoffmann test: X-ray structures of (2S*,3S*,4R*)-2-(N,N-dibenzylamino)-4-diphenylphosphinoyl-1- phenylpentan-3-ol and (2S*,4S*)-2-(N,N-dibenzylamino)-4-diphenylphosphinoyl-1- phenylpentan-3-one
O'Brien, Peter,Powell, Harold R.,Raithby, Paul R.,Warren, Stuart
, p. 1031 - 1039 (2007/10/03)
The Hoffmann test (reaction of a racemic organolithium with a phenylalanine-derived aldehyde) is used to show that lithiated diphenylphosphine oxides are not configurationally stable in THF at -78°C (usual reaction conditions) on the timescale of their rate of reaction with the aldehyde. The test is carried out by reacting lithiated ethyldiphenylphosphine oxide with a phenylalanine-derived aldehyde and because all four diastereoisomeric alcohols are obtained, it is necessary to determine the relative stereochemistry of the products. This is done using a combination of synthesis and X-ray crystallography of (2S*,3S*,4R*)-2-(N,N-dibenzylamino)-4-diphenylphosphinoyl-1- phenylpentan-3-ol and(2S*,4S*)-2-(N,N-dibenzylamino)-2-diphenylphosphinoyl-1- phenylpentan-3-one.
