L-半胱氨酸衍生物的合成及应用

以L-半胱氨酸为手性源，合成了二类多官能团的化合物6和7，并用于醛的不对 称烷基化反应，同时研究了催化剂的结构对反应结果的影响．     

磺氨基醇手性配体的合成及钛配合物催化二乙基锌对醛的不对称加成反应

合成了手性磺氨基醇配体3～5, 将这些配体和Ti(O-i-Pr)₄应用于二乙基锌对醛的不对称加成反应, 获得了好的对映选择性, ee值最高为91%.     

手性氨基酸酰胺催化二乙基锌与芳香醛不对称加成反应

将由磺酰化氨基酸和长链的含甲氧基官能团的胺制备的(S)-N-(4-甲氧基苯乙基)-3-苯基-2-(对甲基苯磺酰胺)丙酰胺(1d)手性配体用于催化二乙基锌与系列芳香醛对映选择性加成反应.15 mol%该催化剂能够对含有吸电子基团、供电子基团及不同位阻的芳香醛均有较好的效果,能够在比较温和的条件下获得高达87%ee和中等程度的产率.     

Enantioselective Addition of Diethylzinc to Aromatic Aldehydes Catalyzed by New Chiral Oxazolidine Ligand

Abstract

The chiral oxazolidine ligand can catalyze the enantioselective addition of diethylzinc to aromatic aldehydes at room temperature with high enantioselectivity (98–99% ee). The conditions for this catalytic process are both mild and simple as compared with the same kind catalyst.     

光学纯7,7′-二取代联二萘酚催化乙基锌对醛的对映选择性加成

合成了一类光学纯的7,7′-二取代联二萘酚, 并将其用在乙基锌对醛的对映选择性加成, 以54%～88%的产率和最高88%的对映选择性得到了光学活性的1-苯基-1-丙醇.     

The Enantioselective Addition of Diethylzinc to Aldehydes Catalyzed by 2-Methylquinoline Derived Chiral Ligands

One of the most important and fundamental synthetic procedures for the establishment of a carbon-carbon bond stereoselectively is the enantioselective addition of organometallic reagents to aldehydes affording chiral secondary alcohols1. In this process, a frequently used method is to perform the reaction in the presence of a chiral ligand such as amino alcohol2. Here, we first report that two new chiral ligands3, which were readily available by the reaction of chiral ketone with lithiated 2-m…     

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.     

水解酶在二乙基锌与芳香醛加成反应中的应用

报道了水解酶催化二乙基锌与芳香醛的加成反应,对反应条件进行了优化.在最适条件(嗜热酯酶APE1547为酶源,反应温度40℃,氯仿为溶剂,4-Cl-苯甲醛为底物)下,加成反应生成的光学活性醇产率最高达78%,ee值最高可达56%.通过实验结果和分子动力学分析对可能的反应机理进行了推测.本研究进一步拓展了酶的非专一性.     

Polymer-Supported N-Sulfonated Amino Alcohol for Titanium(Ⅳ) Catalyzed Diethylzinc Addition to Aldehydes

Homogeneous asymmetric catalysis is one of the most important developments in chemistry in the past several decades. Attachment of chiral ligands to a polymeric support offers important advantages such as facilitated workup procedures, easy recovery and reuse of the catalyst in catalytic reactions. Various chiral ligands supported on polymer have been used as catalysts.     

手性氨基酚催化二乙基锌对芳香醛的不对称加成反应

用易得的原料合成了4个手性氨基酚，这些化合物成功地催化了二乙基锌对醛 的不对称加成反应．其中1a催化间氯苯甲醛和二乙基锌的加成反应获得了较高的化 学产率(95％)和较好的ee值(57％)．     

Enantioselective Addition of Diethylzinc to Aromatic Aldehydes Using Chiral Oxazoline-Based Ligands

Russian Journal of Organic Chemistry - Chiral oxazoline ligands containing an aromatic ring were prepared from norephedrine and pyrrole-2-carbonitrile or 2-hydroxybenzoyl chloride. The synthesized...     

Enantioselective Addition of Phenylacetylene to Aldehydes Catalyzed by Polymer-Supported Sulfonamide

Enantioselective formation of C-C bonds is an area of intense research. Among them, the asymmetric addition of alkynyl reagents to aldehydes is very useful for the synthesis of chiral secondary propargyl alcohols.[1] Recently, many significant homogeneous chiral ligands have been disclosed,[2,3] but very few efficient heterogeneous catalysts have been reported. Herein, we report our research results in the asymmetric addition of phenylacetylene to aldehydes catalyzed by polymer-supported chiral sulfonamide.     

Enantioselective Diethylzinc Addition to Aromatic Aldehydes Catalyzed by Novel Ti(IV) Complex of Three-Dentate Chiral Sulfonamide Ligands

The synthesis of several novel three-dentate sulfonamide alcohol ligands is described, starting from camphorsulfonyl chloride. The influence of temperature and ligand structure on the asymmetric addition of dietylzinc to aromatic aldehydes has been studied. Enantioselectivities up to 76% have been obtained.     

Synthesis of Chiral Pyridylphenols for the Enantioselective Addition of Diethylzinc to Aldehydes

Chiral 8‐substituted 2‐(8,10,10‐trimethyl‐6‐aza‐tricyclo[7.1.1.0^2,7]undeca‐2(7),3,5‐trien‐5‐yl)‐phenols were prepared from a high enantiopurity (>97% ee) of (1R)‐(+)‐α‐pinene, and assessed in the enantioselective addition of diethylzinc to substituted benzaldehydes, giving the (S)‐alcohols with enantiomeric excess ranging from 33% to 89%. Interestingly, in all cases, except for those of ortho‐chlorobenzaldehyde, ortho‐ and para‐methoxybenzaldehydes, the ee was >71%. The plot of the Hammett substitution constants vs. enantiomeric excess of the diethylzinc addition to either the ortho‐ or para‐substituted benzaldehydes shows a linear correlation.     

Enantioselective Addition of Diethylzinc to Aromatic Aldehydes Catalysed by Chiral Ligands Derived from L-Hydroxyproline

The Lithium salts of chiral auxiliaries 2–4 derived from L-Hydroxyprolin (2S, 4R)-1 catalysed the enantioselective addition of diethylzinc to aromatic aldehydes to afford sec alcohols in up to 80% optical purity.     

Synthesis of Chiral Catalysts for the Enantioselective Addition of Diethylzinc to Aromatic Aldehydes

The reaction of diethylzinc with aromatic aldehydes and (S)-porretine derived catalysts was investigated. The synthesis of new chiral catalysts is also described.     

Enantioselective Conjugate Addition of Diethylzinc to Chalcone Catalyzed by Ni（acac）2 and Chiralβ-Amino Alcohols

Enantioselectivge conjugate addition of diethyzinc to chalcone was carried out in the presenee of Ni (acac)2 complexed with five pyrrolidfumyimethanois derived from L-proline. (S)-N-Benzyl-2-(l-hydroxy.l-methylethyl) pyrrolidlne was found to be the best ngnd in asymmetric conjugate addition among the five ligands. The products were obtained with up to 70% ee.The configuration of the product was determined jointly by the substituents on the carbon of the hydroxy group and the nitrogen atom.