Catalytic Enantioselective Synthesis of Bicyclic Lactam <i>N</i>
,<i>S</i>
-Acetals in One Pot by Cascade Transformations
作者:Kaiheng Zhang、Luca Deiana、Erik Svensson Grape、A. Ken Inge、Armando Córdova
DOI:10.1002/ejoc.201900923
日期:2019.8.7
A versatile strategy for the enantioselective synthesis of bicycliclactam N,S-acetals by one-pot cascade transformations is disclosed. The transformation of readily available substrates is promote ...
One-pot reactions of nitroenamines with anilines and ethyl glyoxylate
作者:Mihály V. Pilipecz、Pál Scheiber、Zoltán Vincze、Tamás R. Varga、Gábor Tóth、Péter Nemes
DOI:10.1016/j.tet.2014.04.096
日期:2014.7
In a simple, one-pot, catalyst-free procedure starting from heterocyclic nitroenamines, substituted anilines and ethyl glyoxylate new ethyl 2-arylamino-3-nitro-propionates were prepared in good to excellent yields. Depending on the substituent pattern of the anilines applied, two routes for the one-pot reaction are suggested. Additionally, it was demonstrated that these multifunctional compounds of
Chiral Zirconium Complex as Brønsted Base Catalyst in Asymmetric Direct-type Mannich Reactions
作者:Shū Kobayashi、Matthew M. Salter、Yumi Yamazaki、Yasuhiro Yamashita
DOI:10.1002/asia.200900524
日期:2010.3.1
Activating carbonyls: Asymmetric direct‐type Mannichreaction using a chiralzirconiumcomplex as Brønstedbase is demonstrated. Zirconiumcomplexes prepared from Zr(OtBu) and 3,3′‐disubstituted BINOL are found to be good catalysts in the reactions of an iminoester with malonates, and high enantioselectivities are obtained.
活化羰基:证明了使用手性锆配合物作为布朗斯台德碱的不对称直接型曼尼希反应。在亚氨基酯与丙二酸酯的反应中,发现由Zr(O t Bu)和3,3'-双取代的BINOL制备的锆络合物是良好的催化剂,并获得了高对映选择性。
Transformation of Racemic Azlactones into Enantioenriched Dihydropyrroles and Lactones Enabled by Hydrogen-Bond Organocatalysis
Racemicazlactones are transformed into valuable chiral heterocycles via an asymmetric organocatalytic Mannich reaction followed by gold‐catalyzed cyclization or reduction.
外消旋的内酯通过不对称的有机催化曼尼希反应转化为有价值的手性杂环,然后进行金催化的环化或还原反应。
Demonstration of spontaneous chiral symmetry breaking in asymmetric Mannich and Aldol reactions
作者:Michael Mauksch、Svetlana B. Tsogoeva、Shengwei Wei、Irina M. Martynova
DOI:10.1002/chir.20474
日期:2007.11
stereoselective Mannich and Aldolreactions, in which the product is capable to form H-bridged complexes with the prochiral educt, and found by applying NMR spectroscopy, HPLC analysis, and optical rotation measurements 0.3-50.8% of random product enantiomeric excess under essentially achiral reaction conditions. These findings imply a hitherto overlooked mechanism for spontaneoussymmetrybreaking and, hence, a