196951-16-3Relevant articles and documents
Synthesis of 3-trimethylsiloxy-1-(furan-3-yl)butadiene and its reactions with dienophiles
Mironov, Maxim E.,Bagryanskaya, Irina Yu.,Shults, Elvira E.
, p. 364 - 373 (2016)
[Figure not available: see fulltext.] 3-Trimethylsilyloxy-1-(furan-3-yl)butadiene was synthesized and studied in reactions with 2,2-dimethyl-5-methylidene-1,3-dioxane-4,6-diones, 5-methylenepyrimidine-2,4,6-triones, as well as with imines. Reactions with dienophiles containing an exo-methylene double bond in the presence of L-proline occurred regio- and stereoselectively with the formation of 7-(furan-3-yl)spiro[5,5]undecane-1,5,9-triones or 7-(furan-3-yl)-2,4-diazaspiro[5.5]undecane-1,3,5,9-tetraones. The reaction of diene with methylene imine, obtained from L-phenylalanine methyl ester and formaldehyde, in the presence of Lewis acids led to the formation of 2-(furan-3-yl)piperidin-4-one or the product of ene reaction, methyl (2S)-2-{[(4E)-5-(furan-3-yl)-3-oxopent-4-en-1-yl]amino}-3-phenylpropanoate. The structures of three compounds were confirmed by X-ray structural analysis.
Sequential Two-Step Stereoselective Amination of Allylic Alcohols through the Combination of Laccases and Amine Transaminases
Albarrán-Velo, Jesús,Lavandera, Iván,Gotor-Fernández, Vicente
, p. 200 - 211 (2019/12/03)
A sequential two-step chemoenzymatic methodology for the stereoselective synthesis of (3E)-4-(het)arylbut-3-en-2-amines in a highly selective manner and under mild reaction conditions is described. The approach consists of oxidation of the corresponding racemic alcohol precursors by the use of a catalytic system made up of the laccase from Trametes versicolor and the oxy-radical TEMPO, followed by the asymmetric reductive bio-transamination of the corresponding ketone intermediates. Optimisation of the oxidation reaction, exhaustive amine transaminase screening for the bio-transaminations and the compatibility of the two enzymatic reactions were studied in depth in search of a design of a compatible sequential cascade. This synthetic strategy was successful and the combinations of enzymes displayed a broad substrate scope, with 16 chiral amines being obtained in moderate to good isolated yields (29–75 %) and with excellent enantiomeric excess values (94 to >99 %). Interestingly, both amine enantiomers can be achieved, depending on the selectivity of the amine transaminase employed in the system.
Enantioselective NiH/Pmrox-Catalyzed 1,2-Reduction of α,β-Unsaturated Ketones
Chen, Fenglin,Zhang, Yao,Yu, Lei,Zhu, Shaolin
supporting information, p. 2022 - 2025 (2017/02/15)
The enantioselective 1,2-reduction of α,β-unsaturated ketones was achieved using a NiH catalyst in the presence of pinacolborane. This mild process represents a general method to access a wide variety of structurally diverse α-chiral allylic alcohols in excellent yields and enantioselectivity, as well as very high levels of ambidoselectivity for 1,2- over 1,4-reduction. Furthermore, for reactions on a 10 mmol scale, catalyst loadings as low as 0.5 mol % could be employed to deliver product without any detrimental effect on the yield, enantio-, or ambidoselectivity.
