硫脲衍生物有机催化蒽酮与硝基烯烃的不对称Michael加成反应

将硫脲衍生物用于有机催化蒽酮和β-硝基烯烃的不对称Michael加成反应.考察溶剂、温度及催化剂用量等对反应催化性能的影响.结果表明,最佳催化条件为5%(摩尔百分数)催化剂1f,二氯甲烷为溶剂,室温反应.得到了80%~97%的化学产率和最高达99%ee的对映选择性.     

有机催化蒽酮与β-硝基烯烃的不对称Michael加成反应

将金鸡纳生物碱衍生物用于催化蒽酮和β-硝基芳基乙烯的不对称Michael加成反应。 考察了溶剂、温度及催化剂用量对反应催化性能的影响。 结果表明,最佳条件为5%(摩尔分数)催化剂1b、甲苯为溶剂、0 ℃反应,得到了91%~99%的化学产率和最高达95%ee的对映体选择性。     

有机催化不对称Michael加成反应

有机催化的不对称合成反应是目前研究最为活跃的领域之一. 不对称Michael加成反应是合成众多重要的手性合成子和药物中间体的有效手段. 目前报道的催化Michael加成反应的有机催化剂主要有脯氨酸及其衍生物、手性咪唑啉酮、手性(硫)脲、金鸡纳碱衍生物等. 对各类有机催化剂在有机催化不对称Michael加成反应中的应用, 以及不对称诱导反应的机理、催化剂分子结构及反应条件对其催化活性和不对称诱导作用的影响进行了评述.     

查尔酮参与的不对称Michael加成反应研究进展

综述了近十年来,金鸡纳碱、硫脲、手性离子液体、季铵盐、脯氨酸和葡萄糖类衍生物等有机小分子在催化查尔酮的不对称Michael加成反应中的应用.有机小分子催化的机理大部分都是通过氢键、离子键等与底物相互作用而使其有较好的对映选择性.     

有机催化丙二酸酯与β-硝基烯烃的不对称Michael加成反应

将金鸡纳生物碱衍生物用于催化丙二酸酯和β-硝基芳基乙烯的不对称Michael加成反应。考察溶剂、温度及催化剂用量对反应催化性能的影响。结果表明,最佳催化条件为5 mol%催化剂1e,甲苯为溶剂,0℃反应。得到了86～93%的化学产率和最高达99%ee的对映选择性。     

双功能手性硫脲催化的不对称Michael加成反应研究进展

手性有机小分子催化是近年来不对称催化领域的一个热门研究课题.其具有反应条件温和、环境友好等优点,符合绿色化学的要求.手性氨基-硫脲类催化剂,特别是双功能的手性硫脲,已经在众多的不对称反应中表现出了优秀的催化性能.主要综述了双功能手性硫脲在不对称Michael加成反应中的应用,并对其前景及发展趋势作了展望.     

L-丙氨酰Betti碱催化环己酮对硝基烯不对称Michael加成反应

合成了3个手性Betti碱的L-丙氨酰衍生物, 并用它们来催化环己酮与硝基烯的Michael加成反应. 发现1a是其中最有效的催化剂, ee值最高大于99%, dr值最高大于99∶1. 考察了催化剂结构与用量、添加剂用量、底物结构等因素对反应的化学产率和光学收率的影响.     

不对称催化的有机锌试剂对酮的加成反应研究进展

按照手性配体的结构类型分类, 综述了近年来有机锌试剂对酮、α-酮酯等化合物的不对称加成反应的研究进展, 对高效、高选择性的手性配体在该类反应中的应用进行了重点评述.     

有机小分子催化的烯酮的不对称环加成反应

重点从立体选择性和催化机理方面,总结了不同的有机小分子催化剂在烯酮的[2+2]和[4+2]不对称环加成反应中的应用.     

硝基化合物的不对称迈克尔加成反应

从以下三方面对硝基化合物的不对称迈克尔加成反应进行了较为详细的综述： （1）手性催化剂催化的迈克尔加成，（2）共轭硝基物与手性亲核试剂的迈克加成 ，（3）脂肪族硝基物对手性迈克加成受体的迈克尔加成。     

Catalytic Enantioselective Addition of Thioacids to Trisubstituted Nitroalkenes

The first example of a catalytic enantioselective addition to and nitronate protonation of trisubstituted nitroalkenes to produce highly enantioenriched products with a tetrasubstituted carbon is reported. Thioacids added in excellent yields and with high enantioselectivities to both activated and unactivated nitroalkenes. The 1,2‐nitrothioacetate products can be readily converted in two steps to biomedically relevant 1,2‐aminosulfonic acids without loss of enantiopurity.     

Enantioselective Organocatalytic Conjugate Addition of Aldehydes to Vinyl Sulfones and Vinyl Phosphonates as Challenging Michael Acceptors

Chiral framework : Chiral amines with pyrrolidine frameworks catalyze the enantioselective conjugate addition of a wide range of aldehydes to various vinyl sulfones and vinyl phosphonates in high yields and with enantioselectivities up to >99 % ee (see scheme). The high versatility of the Michael adducts is exemplified by various functionalizations with conservation of the optical purity.

     

Enantioselective Michael Addition of Water

The enantioselective Michael addition using water as both nucleophile and solvent has to date proved beyond the ability of synthetic chemists. Herein, the direct, enantioselective Michael addition of water in water to prepare important β‐hydroxy carbonyl compounds using whole cells of Rhodococcus strains is described. Good yields and excellent enantioselectivities were achieved with this method. Deuterium labeling studies demonstrate that a Michael hydratase catalyzes the water addition exclusively with anti‐stereochemistry.     

Enantioselective Sulfur‐Michael Addition of Thioacetic Acid to Nitroalkenes Catalyzed by Bifunctional Amine‐Thiourea Catalysts

An enantioselective Michael addition of thioacetic acid (AcSH) to nitroalkenes, catalyzed by a leucine‐derived bifunctional amine? thiourea, was developed with high yields and moderate enantioselectivities. The thiourea‐ammonium salt formed in the reaction is identified as the active catalyst, and the multiple H‐bonding system is responsible for the stereocontrol. The resulting thioester products are useful intermediates for the synthesis of enantiomerically enriched S‐containing compounds.     

Enantioselective and Regioselective Organocatalytic Conjugate Addition of Malonates to Nitroenynes

The first catalytic asymmetric conjugate addition of 1,3‐dicarbonyl compounds to nitroenynes catalyzed by cinchona alkaloid‐based thiourea organocatalysts has been developed. The 1,4‐addition adducts were obtained solely, in moderate to good yields (up to 93 %) with good enantioselectivities (up to 99 % ee). This protocol affords a conceptually different entry to the precursors of pharmaceutically important chiral β‐alkynyl acid derivatives and synthetically useful chiral nitroalkynes. Notably, the protocol worked well with both aryl‐ and alkyl‐substituted alkynyl substrates.