854019-24-2Relevant academic research and scientific papers
Highly enantioselective Biginelli reaction promoted by chiral bifunctional primary amine-thiourea catalysts: Asymmetric synthesis of dihydropyrimidines
Wang, Yangyun,Yang, Haitao,Yu, Jipan,Miao, Zhiwei,Chen, Ruyu
, p. 3057 - 3062 (2009)
The diastereospecific formation of dihydropyrimidines (DHPMs) has been achieved in moderate to high yields with up to 99% ee by a Biginelli reaction. The reaction was performed by using a combined catalyst consisting of a chiral bifunctional primary amine
Towards Enzyme-like, Sustainable Catalysis: Switchable, Highly Efficient Asymmetric Synthesis of Enantiopure Biginelli Dihydropyrimidinones or Hexahydropyrimidinones
Lillo,Saá
supporting information, p. 17182 - 17186 (2016/11/23)
Organocatalysts displaying a network of cooperative hydrogen bonds (NCHB) have been employed in an enzyme-like manner for a direct, switchable synthesis of enantiopure hexahydropyrimidinones (HHPMs) or dihydropyrimidinones (DHPMs), which starts at a common, easily accessible α-ureidosulfone stage. The NCHB organocatalyst exploits all its potential as a pure hydrogen-bond biomimetic catalyst even in the presence of organic bases. This one-pot, diastereo- and enantioselective synthetic procedure has been proven to be robust, scalable, highly efficient, and environmentally benign. A straightforward and truly practical entry to enantiopure HHPMs is reported for the first time.
Solution-phase synthesis and evaluation of tetraproline chiral stationary phases
Dai, Zhi,Ye, Guozhong,Pittman Jr., Charles U.,Li, Tingyu
experimental part, p. 329 - 338 (2012/05/20)
A protocol was developed for the solution-phase synthesis of multigram amounts of two 9-fluorenylmethoxycarbonyl (Fmoc)-protected tetraproline peptides. These tetraproline peptides were then attached to amino derivatized silica gel. The replacement of the Fmoc group with the trimethylacetyl group lead to two tetraproline chiral stationary phases (CSPs). A comparison of the chromatographic behavior of these two solution-phase-synthesized tetraproline CSPs with that prepared by stepwise solid-phase synthesis revealed that all three had similar chromatographic performance for resolving 53 model analytes. This suggests that the solution-phase synthesis of oligoprolines, which allows for the specific benefits of good batch reproducibility, selector homogeneity, and possibly low cost, is a feasible alternative to the solid-phase synthesis of oligoproline CSPs. Copyright
Bifunctional primary amine-thiourea-TfOH (BPAT·TfOH) as a chiral phase-transfer catalyst: The asymmetric synthesis of dihydropyrimidines
Wang, Yangyun,Yu, Jipan,Miao, Zhiwei,Chen, Ruyu
experimental part, p. 3050 - 3054 (2011/05/17)
An enantioselective Biginelli reaction has been developed by using a bifunctional primary amine-thiourea-TfOH (BPAT·TfOH) as a chiral phase-transfer catalyst and t-BuNH2·TFA as an additive in saturated brine at room temperature. The correspondi
Primary amine catalyzed Biginelli reaction for the enantioselective synthesis of 3,4-dihydropyrimidin-2(1H)-ones
Ding, Derong,Zhao, Cong-Gui
supporting information; experimental part, p. 3802 - 3805 (2010/08/22)
Several chiral primary amines, mainly those derived from cinchona alkaloids, were evaluated as organocatalysts for the asymmetric Biginelli reaction. With quinine-derived amine catalyst 1 and after extensive optimization of the reaction conditions, 3,4-di
