Chiral Ferrocenyl Amino Alcohols：Preparation and Application as Catalysts in the Enantioselective Reduction of Ketones Using NaBH4／I2

Five novel chiral ferrocenyl amino alcohols were prepared from natural amino acids and used as catalysts in the asymmetric reduction of prochiral ketones with NaBH4/I2 combination.The incorporation of the ferrocenyl moiety into the molecule of the chiral amino alcohols greatly improved their enantioselectivity in the catalysis.The optically active secondary alcohols were obt5ained in moderate to good enantiomeric excesses and high chemical yields.     

Enantioselective Reduction of Achiral Ketones with NaBH_4/I_2 Catalyzed by (S)-Ferrocenyl Amino Alcohols

In recent years much attention has been devoted to the enantioselective synthesis of optically active alcohols which are important starting materials for many biologically active compounds1. Since Corey and co-workers found the chiral oxazaborolidine catalyzed reduction (CBS reduction) of prochiral ketones, the method for the generation of chiral secondary alcohols has become one of the most attractive research fields2, 3. But borane and its complexes such as borane-THF or borane-dimethyl …     

含流手性β-氨基醇的合成及其在对映选择性还原反应中的应用

S烷基-L-半胱氨酸2a～2c通过酯化、格林亚反应合成了光学活性含硫β-氨基 醇4a-4c，并用于潜手性酮的对映选择性NaBH_4／12还原．光学活性二级醇化学产 率很高，对映体过量最高可达93％．     

雪松胺醇-硼烷络合物催化的潜手性酮的不对称还原反应

雪松胺醇-硼烷络合物催化的潜手性酮的不对称还原反应     

手性氨基醇催化的苯乙炔与酮的对映选择性加成

(S)-(1-Benzylpyrrolidin-2-yl)diphenylmethanol and cinchonine were evaluated as promotors in the asymmetricadditions of phenylacetylene to ketones,in order to prepare chiral propargylic alcohols.Good yields(up to 89%)and moderate enantioselectivities(up to 77.9% ee)were achieved.Addition of Ti(OPr-i)_4 can significantly improvethe enantioselectivity of the reaction.     

奎宁与钴（Ⅱ）手性络合物用于前手性酮的不对称催化还原

奎宁与钴（Ⅱ）手性络合物用于前手性酮的不对称催化还原刘湘＊李纪国张正（无锡轻工大学化工系无锡２１４０３６）（南京大学化学系南京）关键词手性络合物，不对称还原，前手性芳香酮１９９６－１０－２５收稿，１９９７－０４－２２修回前手性酮的不对称催化还原作为光...     

不对称硼烷还原合成手性氨基醇

用原位生成的手性噁唑硼烷为催化剂,用2molBH3对1molα 或β 氨基酮进行了对映选择性还原,生成光学活性氨基醇 硼烷络合物,后者脱去BH3后给出光学活性氨基醇,ee值最高达99%.讨论了氨基酮结构与反应选择性的关系.     

用芹菜茎催化对映选择性还原芳香酮

研究了用芹菜茎薄片在温和与环境友好的条件下催化芳香酮的对映选择性还原反应, 制备得到具有光学活性的(S)-1-芳基醇, 产物的对映选择性符合Prelog规则. 考察了pH值、反应时间、反应温度、底物浓度等因素对底物芳香酮的转化率和产物(S)-1-芳基醇的对映体过量值的影响, 并优化了这些反应条件. 文中还研究了底物的构效关系, 发现羰基两边取代基的空间效应和电子效应明显影响底物的转化率和产物的对映体过量值. 在合适的条件下底物苯乙酮的转化率高达100%, 产物(S)-1-苯基乙醇的对映体过量值大于99.0%. 苯丙酮、对甲基苯乙酮和对氯苯乙酮等其它芳香酮的转化率达到中等程度, 但所得(S)-1-芳基醇的最大对映体过量值均大于99.0%.     

手性氨基醇催化的前手性芳酮的不对称还原反应

首次以天然D-樟脑的衍生物为原料, 合成了两个新型龙脑基氨基醇配体, 研究了它们与硼烷原位制备成手性噁唑硼烷后, 在不对称催化氢化还原前手性芳酮中的性能, 得到的手性仲醇的对映体过量(ee)值最高可达96%, 还考察了反应温度、时间、溶剂等因素对苯乙酮的不对称氢化还原的化学产率和光学收率的影响.     

Chemoenzymatic Synthesis of Enantiopure Amino Alcohols from Simple Methyl Ketones

This study highlights the straight-forward synthesis of substituted 1,2-amino alcohols from simple and readily available aromatic methyl ketones. Starting from acetophenone derivatives, the straight-forward synthesis strategy involved an initial bromination of the alpha-positioned methyl group in the first step, followed by a simple hydrolysis to the hydroxyketone (2-hydroxyacetophenone). The hydroxylated intermediate was subsequently converted from Silicibacter pomeroyi to the final 1,2-amino alcohol by using the transaminase. The transaminase-catalyzed reaction proceeded with yields up to 62 % and always excellent enantiomeric excess of >99 %. Interestingly, the keto-enol-tautomerism of the hydroxyl ketone yields an unexpected amino alcohol isomer.     

Synthesis of N-Squaramidoacids and Their Application in Asymmetric Borane Reduction of Prochiral Ketones

A series of novel N-squaramidoacid ligands were prepared conveniently. Without converting to corresponding amino alcohols, these ligands could be used in asymmetric borane reduction of prochiral aromatic ketones to give secondary alcohols in good to excellent enantiomeric excesses. The results showed that N-squaramidoacids are more efficient ligands than N-sulfonyl amino acids. N-Squaryl proline was proved to be an excellent ligand in this catalytic asymmetric process.     

手性氨基醇（R）－2－氨基－1，1－二苯基－3－（2－萘基）－1－丙醇：制备及其对前手性酮硼烷还原的对映选择性催化作用

用丙二酸酯法合成了Ｎ－乙酰基－３－（２－萘基）－ＤＬ－α－丙氨酸乙酯３．３经酶法拆分，得光学活性的Ｄ－３，后者经盐酸水解、酯化后再与苯基溴化镁作用，制得标题化合物６。在０．５ｍｍｏｌ６存在下，用过量硼烷对一系列前手性酮还原，得到了相应的光学活性二级醇。对映体过量（ｅ．ｅ值）５７．０～１００％。     

Convenient Asymmetric Borane Reduction of Ketones Catalyzed by Simple Amino Alcohols and Corresponding Amino Acids

The catalytic enantioselective borane reduction of ketones is a well-studied theme1. Since the pioneering work of Corey2, a variety of good catalysts have been synthesized through further modification on simple amino alcohols and their corresponding amino acids,3,4 . But when simple amino alcohols were directly used in the reduction their catalytic efficiency was very low. For the first time Buono5 has reported through carefully chosen reaction condition the catalytic efficiency of a simple…     

含硫手性β-氨基醇的合成及其在对映选择性还原反应中的应用

S-烷基-L-半胱氨酸2a～2c通过酯化、格林亚反应合成了光学活性含硫β-氨基醇4a～4c,并用于潜手性酮的对映选择性NaBH4/I2还原.光学活性二级醇化学产率很高,对映体过量最高可达93%.     

A New Chiral Catalyst for the Enantioselective Reduction of Prochiral Ketones with Borane

A new chiral β-amino alcohol, (s)-2-amino-1, 1-diphenyl-3-(2-naphthyl)-1-propanol and its use as a catalyst in the enantioselective reduction of prochiral ketones with borane were described.     

N-磺化手性β-氨基醇修饰的钛试剂催化下的酮的不对称炔基化反应研究

The easily prepared and recoverable chiral N-sulfonylated fl-amino alcohol 2 in combination with Ti（OPr-i）4 was found to be an effective chiral catalyst for the enantioselective addition of alkynylzinc to ketones, which gave the useful products, i.e. chiral tertiary propargyl alcohols, with the ee up to 92%.     

二苯基脯氨醇及其衍生物对前手性酮的不对称催化还原研究进展

对(S)-α,α-二苯基脯氨醇及其衍生物对前手性酮的不对称催化还原研究进行了综述, 表明它们具有催化还原产率高、对映选择性好的作用, 是一类性能优秀的不对称还原反应的有机小分子催化剂.     

Synthesis of Novel Chiral Ionic Liquid and Its Application in Reduction of Prochiral Ketones to the Corresponding Chiral Alcohols Using NaBH4

A novel chiral ionic liquid (CIL) based on nicotinium salt has been synthesized and used as an efficient asymmetric chiral catalyst for reduction of acetophenone derivatives with NaBH₄ in methanol at room temperature. The optically active alcohols were obtained in low to moderate enantiomeric excess in a short reaction time.     

亚胺的对映选择性催化还原研究进展

亚胺的对映选择性催化氢化是近年来不对称催化反应中的一个新热点, 本文综述了自1973 年Kagan 等人首次报道亚胺对映选择性催化还原以来本领域的研究进展。