Solution-phase synthesis and evaluation of tetraproline chiral stationary phases
作者:Zhi Dai、Guozhong Ye、Charles U. Pittman、Tingyu Li
DOI:10.1002/chir.22001
日期:2012.4
solution‐phasesynthesis 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 tetraprolinechiralstationaryphases (CSPs). A comparison of the chromatographic behavior of these two solution‐phase‐synthesized
reaction was performed by using a combined catalyst consisting of a chiral bifunctional primary amine-thiourea 9f and a Brønsted acid with tert-butylammonium trifluoroacetate (t-BuNH2⋅TFA) as additive in dichloromethane at room temperature. The possible mechanism for the reaction has been proposed to explain the origin of the activation and the asymmetric induction.
Primary Amine Catalyzed Biginelli Reaction for the Enantioselective Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones
作者:Derong Ding、Cong-Gui Zhao
DOI:10.1002/ejoc.201000448
日期:——
Several chiral primary amines, mainly those derived from the cinchona alkaloids, were evaluated as the organocatalysts for the asymmetric Biginellireaction. With the quinine-derived amine catalyst 1 and after extensive optimization of the reaction conditions, 3,4-dihydropyrimidin-2(1H)-ones were obtained in moderate to good yields and 51-78% ee from a three-component reaction of aryl and aliphatic
几种手性伯胺,主要来自金鸡纳生物碱,被评估为不对称 Biginelli 反应的有机催化剂。使用奎宁衍生的胺催化剂 1 和反应条件的广泛优化后,3,4-二氢嘧啶-2(1H)-酮以中等至良好的收率和 51-78% ee 从芳基的三组分反应中获得和脂肪醛、尿素和乙酰乙酸酯。
Bifunctional primary amine-thiourea–TfOH (BPAT·TfOH) as a chiral phase-transfer catalyst: the asymmetric synthesis of dihydropyrimidines
作者:Yangyun Wang、Jipan Yu、Zhiwei Miao、Ruyu Chen
DOI:10.1039/c0ob01268h
日期:——
An enantioselective Biginelli reaction has been developed by using a bifunctional primary amine-thioureaâTfOH (BPAT·TfOH) as a chiral phase-transfer catalyst and t-BuNH2·TFA as an additive in saturated brine at room temperature. The corresponding dihydropyrimidines were obtained in moderate-to-good yields with up to 99% ee under mild conditions. A plausible transition state has been proposed to explain the origin of the activation and the asymmetric induction.
ENANTIOSELECTIVE SYNTHESIS OF DIHYDROPYRIMIDINONES AND HEXAHYDROPYRIMIDINONES
申请人:Universitat de les Illes Balears
公开号:EP3260446A1
公开(公告)日:2017-12-27
The present invention provides with a "one pot" easily scalable preparation process, or method to obtain enantiomerically enriched dihydropyrimidinones (DHPMs), in high yield and high enantiomeric purity, based on the concept of organocatalysis by a network of cooperative hydrogen bonds (NCHB). Said preparation process obtains enantiomerically enriched DHPMs without the use of metal-based catalysis and with the possibility of the recovery of the chiral organocatalyst comprising a NCHB used. The present invention also provides with new enantiomerically and diastereomerically enriched hexahydropyrimidinones (HHPMs), as well as a preparation process to obtain them also based on the concept of organocatalysis by a NCHB. Said preparation process obtains enantiomerically and diastereomerically enriched HHPMs without the use of metal-based catalysis and with the possibility of the recovery of the chiral organocatalyst comprising a NCHB used.