The asymmetric challenge! New camphor‐based prolinamides were designed, synthesized, and proven to be a highly efficient organocatalysts for asymmetricMichael reactions. Treatment of unmodified aldehydes with nitroalkenes in the presence of 5–10 mol % organocatalysts provided the desired Michael products in high chemical yields (up to 94 %) and high to excellent levels of diastereo‐ and enantioselectivities
Translating the Enantioselective Michael Reaction to a Continuous Flow Paradigm with an Immobilized, Fluorinated Organocatalyst
作者:Irina Sagamanova、Carles Rodríguez-Escrich、István Gábor Molnár、Sonia Sayalero、Ryan Gilmour、Miquel A. Pericàs
DOI:10.1021/acscatal.5b01746
日期:2015.11.6
enantioselective, continuous flow processes allowing either the multigram synthesis of a single Michael adduct over a 13 h period or the sequential generation of a library of enantiopure Michael adducts from different combinations of substrates (13 examples, 16 runs, 18.5 h total operation). A customized in-line aqueous workup, followed by liquid–liquid separation in flow, allows for product isolation
The direct Michaeladdition of aldehydes and ketones to nitroolefins, catalyzed by N-i-Pr-2,2′-bipyrrolidine, is described. The desired 1,4-adducts are obtained in excellent yields with enantioselectivities up to 95% ee and dr up to 95 : 5 of the syn aldehydeaddition product. An unexpected inversion of diastereoselectivity was observed for the addition of α-hydroxy ketones to β-arylnitroolefins with
The highly enantioselective preparation of drug-like oxa-spirocyclic indanone derivatives employing a multicomponentcascadereaction is described. This approach utilizes an organocatalytic Michaelreaction followed by a Henry–acetalization sequence that yields the desired chiral spirocyclic backbone, bearing four contiguous stereogenic centers and multiple functional groups, in good yields and high
描述了使用多组分级联反应制备类药物氧杂-螺环茚满酮衍生物的高度对映选择性制备。这种方法利用有机催化迈克尔反应,然后是亨利缩醛化序列,产生所需的手性螺环骨架,带有四个连续的立体中心和多个官能团,具有良好的产率和高立体选择性(高达 99% ee 和 95:5 dr) .
3,3‘-Bimorpholine Derivatives as a New Class of Organocatalysts for Asymmetric Michael Addition
New N-alkyl-3,3'-bimorpholine derivatives (iPBM) were revealed to be efficient organocatalysts for the asymmetric direct Michael addition of aldehydes to nitroolefins and a vinyl sulfone. In these transformations using iPBM, 1,4-adducts were afforded in high yields, with good to high levels of diastereo- and enantioselectivity. The stereochemical outcome of the reaction could be explained by an acyclic