1009643-85-9Relevant academic research and scientific papers
Chiral hybrid materials based on pyrrolidine building units to perform asymmetric Michael additions with high stereocontrol
Llopis, Sebastián,García, Teresa,Cantín, ángel,Velty, Alexandra,Díaz, Urbano,Corma, Avelino
, p. 5835 - 5847 (2018/11/24)
A new chiral mesoporous hybrid material was synthesized based on pyrrolidine units included in a siliceous framework, HybPyr, and integrated into the organic-inorganic structure, from a specific bis-silylated precursor. A fluoride sol-gel methodology under soft synthesis conditions and in the absence of sophisticated structural directing agents allowed the generation of a mesoporous architecture with a homogeneous distribution of active chiral moieties along the network. The hybrid material was studied by means of different characterization techniques (TGA, NMR and IR spectroscopy, chemical and elemental analyses, TEM, and textural measurements), verifying the stability and integrity of the asymmetric active sites in the solid. The hybrid material, HybPyr, is an excellent asymmetric heterogeneous and recyclable catalyst for enantioselective Michael addition of linear aldehydes to β-nitrostyrene derivatives with high stereocontrol of the reaction products.
Synthesis of new pyrrolidine-based organocatalysts and study of their use in the asymmetric Michael addition of aldehydes to nitroolefins
Castán, Alejandro,Badorrey, Ramón,Gálvez,Díaz-De-Villegas
supporting information, p. 612 - 619 (2017/06/20)
New pyrrolidine-based organocatalysts with a bulky substituent at C2 were synthesized from chiral imines derived from (R)-glyceraldehyde acetonide by diastereoselective allylation followed by a sequential hydrozirconation/iodination reaction. The new compounds were found to be effective organocatalysts for the Michael addition of aldehydes to nitroolefins and enantioselectivities up to 85% ee were achieved.
Application of l-prolinamides as highly efficient organocatalysts for the asymmetric Michael addition of unmodified aldehydes to nitroalkenes
Naziroglu, Hayriye Nevin,Durmaz, Mustafa,Bozkurt, Selahattin,Demir, Ayhan Sitki,Sirit, Abdulkadir
experimental part, p. 164 - 169 (2012/05/20)
The asymmetric Michael addition of aldehydes to nitroolefins was investigated using a combination of l-prolinamide derivatives and various acidic additives. (S)-1,1′-Bi-2-naphthol was found to be the most effective co-catalyst and afforded the nitroaldehy
Ionic liquid-supported (ILS) (S)-pyrrolidine sulfonamide for asymmetric Michael addition reactions of aldehydes with nitroolefins
Omar, Emmy M.,Dhungana, Kritanjali,Headley, Allan D.,Rahman, Mohd Basyaruddin Abdul
experimental part, p. 170 - 175 (2012/04/05)
A class of ionic liquid supported (ILS) (S)-pyrrolidine sulfonamide organocatalyst (1c), which was developed earlier in our lab, has been applied to a wider range of Michael addition reaction, involving various aryl-substituted nitroolefins and a series of aldehydes. Catalyst 1c catalyzes Michael additions in which only 2 equivalents of aldehydes to each equivalent of nitroolefin are required. With 10 mol% of ILS catalyst 1c loading, moderate to excellent yields (51-98%) with moderate enantioselectivities (28-83% ee) and high diastereoselectivities (syn/anti ratio up to 97/3) were obtained. Moreover, the catalyst 1c could be easily recycled and reused for at least 5 times with slightly reduced activities.
Self-assembly of organocatalysts for the enantioselective Michael addition of aldehydes to nitroalkenes
Demir, Ayhan S.,Eymur, Serkan
experimental part, p. 112 - 115 (2010/04/06)
A proline-thiourea self-assembled organocatalyst is described as a good catalyst for the enantioselective nitro-Michael addition of aldehydes to nitroalkenes. The reaction is efficient with 5% of the thiourea, to give moderate to good enantioselectivity (up to 76% ee). High syn-selectivity was obtained with both branched and unbranched aliphatic aldehydes. This is the first example of self-assembly of organocatalysts with an achiral additive in a Michael addition wherein aldehydes are utilized as donors.
Novel chiral ammonium ionic liquids as efficient organocatalysts for asymmetric Michael addition of aldehydes to nitroolefins
Wang, Wan-Hui,Wang, Xiang-Bo,Kodama, Koichi,Hirose, Takuji,Zhang, Guang-You
experimental part, p. 4970 - 4976 (2010/08/20)
Two chiral ammonium ionic liquids 1a and 1b have been newly synthesized from commercially available (+)-cis-2-benzamidocyclohexanecarboxylic acid. These CILs have been demonstrated to be efficient organocatalysts for asymmetric Michael addition of aldehyd
Highly efficient catalytic system for enantioselective Michael addition of aldehydes to nitroalkenes in water
Zhu, Shaolin,Yu, Shouyun,Ma, Dawei
, p. 545 - 548 (2008/09/21)
(Chemical Equation Presented) Organocatalysis: A highly effective catalytic procedure for the Michael addition of aldehydes to nitroalkenes is achieved by combining the excellent asymmetric induction ability of o-TMS-protected diphenylprolinol compounds, the quick formation of enamines in the presence of benzoic acid, and the highly concentrated organic phase in water (see scheme; TMS=trimethylsilyl).
Asymmetric Michael addition reactions of aldehydes with nitrostyrenes catalyzed by functionalized chiral ionic liquids
Zhang, Qianying,Ni, Bukuo,Headley, Allan D.
, p. 5091 - 5097 (2008/09/21)
A new class of pyrrolidine-based functionalized chiral ionic liquids (FCILs) has been developed and shown to be effective and reusable catalysts for the asymmetric Michael addition reactions. For the Michael addition reaction involving various aldehydes a
