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%.     

合成(R)-2-异戊氧基丙醇的新方法

以(R)-1,2-丙二醇为原料,经伯醇羟基保护、仲醇O-异戊基取代、脱羟基保护三步反应合成了手性醇(R)-2-异戊氧基丙醇,其结构经NMR和MS确证.     

用薄层色谱法分离芳香醇胺药物对映体

用D－10-樟脑磷酸铵作为手性离子对试剂添加到流动相中,在硅胶GF254薄层板上分离了两种芳香醇胺类药物对映体。     

Anti-Markovnikov Hydroamination of Racemic Allylic Alcohols to Access Chiral γ-Amino Alcohols

A ruthenium-catalyzed formal anti-Markovnikov hydroamination of allylic alcohols for the synthesis of chiral γ-amino alcohols is presented. Proceeding via an asymmetric hydrogen-borrowing process, the catalysis allows racemic secondary allylic alcohols to react with various amines, affording enantiomerically enriched chiral γ-amino alcohols with broad substrate scope and excellent enantioselectivities (68 examples, up to >99 % ee).     

CBS催化合成R-3-奎宁醇

探讨R-3-奎宁醇的合成工艺。通过手性合成的方法,以3-奎宁酮盐酸盐为原料,经CBS催化剂催化还原得R-3-奎宁醇。收率可达到92%以上,ee值可达98%以上。该合成路线操作步骤简单、收率高,具有工业应用价值。     

联二萘酚类磷酸吡哆醛模拟酶的合成与应用研究进展

模拟酶化合物的合成与应用研究具有重要的理论和实际意义。近年来研究的一些联二萘酚类磷酸吡哆醛模拟酶具有氨基酸构型转换的功能,并可用于手性氨基醇的对映选择性识别。本文简要介绍了该类化合物的合成方法,综述了近年来联二萘酚类磷酸吡哆醛模拟酶在手性氨基酸构型转换、手性氨基醇对映选择性识别以及萃取拆分等方面的应用。     

The first catalytic asymmetric addition of diethylzinc to aldehyde promoted by chiral thiourea

A series of C₂-symmetric and asymmetric chiral thiourea derivatives were synthesized from commercial L-phenylalanine.All of the new compounds have been fully characterized by IR,¹H NMR,¹³C NMR,MS spectra and elemental analyses.The chiral thioureas were used as chiral ligands in the catalytic enantioselective ethylation of aldehydes with diethylzinc,the corresponding sec-alcohols were gained with excellent enantioselectivities（up to 87.1%ee） and high yields（up to 76.7%） after the conditions were optimized.     

Enantioselective Alkynylation of Ketones Promoted by β-Sulfonamide Alcohol-Titanium Complexes

A readily available β-sulfonamide alcohol-titanium complex was found to be effective on promoting the asymmetric addition reaction of an alkynylzinc reagent to unactivated simple ketones under very mild conditions. And the corresponding chiral tertiary propargylic alcohols were obtained with enantiomeric excesses of up to 86%, which provided a simple, practical and inexpensive method to generate chiral tertiary propargylic alcohols.     

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.     

Highly Enantioselective Intramolecular Morita‐Baylis‐Hillman Reaction Catalyzed by Mannose‐Based Thiourea‐phosphine

The saccharide‐based chiral bifunctional thiourea‐phosphines were developed as chiral organocatalysts for the intramolecular Morita‐Baylis‐Hillman reaction of ω‐formyl‐enones. With only 2 mol% of thiourea‐phosphine catalyst 3c , chiral functionalized cyclohexenes were achieved under mild reaction conditions with excellent yields and enantioselectivities.     

Lewis Base Organocatalyzed Enantioselective Hydrosilylation of α-Keto Ketimines

A chiral Lewis base organocatalyzed enantioselective hydrosilylation ofa-keto ketimines was investigated.The reactions afforded various enantioenriched a-amino ketones with good yields（up to 95％） in moderate to good enantioselectivities（up to 98％ e.e.）.Furthermore,one of the products was reduced to a chiral 1,2-amino alcohol.Following cyclization of it with triphosgene generated a cannabinoid receptor 1 （CB 1） inhibitor with good diastereoselectivity.     

用手性配体改性铝锂试剂对芳香酮的还原

用手性一元酮作辅助配体,与１,２,５,６－二丙酮甘ｉＡｌｈ５对芳香酮进行对映选择 的,得到光学活性产物８个。通过与α－乙酰氧基－Ｌ－丙酰氯生成非对映异构体酯,经气相色谱分析,芳酮挑学产率为２３．３￣７１．２％。初步探讨了配体之间对称性匹配的情况。     

R-兰索拉唑的合成新方法

2-氯甲基-3-甲基-4-（2,2,2-三氟乙氧基）吡啶盐酸盐和2-巯基苯并咪唑经缩合反应得到兰索拉唑硫醚;以L-亮氨酸经结构修饰得到的二齿手性氨基醇为催化剂、叔丁基过氧化氢为氧化剂,不对称氧化兰索拉唑硫醚得到R-兰索拉唑粗品。经分离纯化得到产物,e.e.值99.5%,两步反应总收率43.3%。产物经IR、MS、^1H-NMR、手性HPLC确证。     

扁桃酸及其衍生物对映体的手性识别研究

以两种手性氨基醇作为主体,运用1H NMR分别考察其对客体7个扁桃酸衍生物对映异构体的手性识别能力。结果表明,主客体物质的量之比为1∶1时,主体诱导客体对叔丁基扁桃酸消旋体最高产生37.6 Hz的化学位移差值。     

Stereocontrolled synthesis of tertiary silanes via optically pure 1,3,2-oxazasilolidine derivatives

Optically pure 1,3,2-oxazasilolidine derivatives were synthesized from a chiral 1,2-amino alcohol. These heterocyclic compounds containing a stereogenic silicon atom produced tertiary silanes with excellent optical purity through successive reactions with Grignard reagents and diisobutylaluminum hydride. Stereochemical course of the reactions of the oxazasilolidine at the chiral silicon atom was elucidated based on the absolute configurations of the products and the substrate which were determined by chiral HPLC and X-ray crystallographic analyses.     

手性配体催化二烷基锌—羰基不对称加成制光活性醇的反应

关于手性配体催化二烷基锌一羰基的不对称加成生成光活性醇的反应,从催化剂、不对称催化机理与自催化过程、手性放大等方面进行了概述,参考文献50篇。     

新型手性氨基醇的合成及其对布洛芬对映异构体的手性识别

5-叔丁基-2-二甲氨基苯甲醛与L-苯甘氨酸经酯化、格氏反应途径的产物二齿手性氨基醇经缩合、还原反应,得到新型三齿手性氨基醇(2S)-2-(5-叔丁基-2-二甲氨基)苯甲氨基-1,1,2-三苯基乙醇,运用1H NMR考察了该新型三齿手性氨基醇作为主体对客体布洛芬消旋体的手性识别能力。     

L-亮氨酸衍生物手性氨基醇的合成及其对布洛芬和扁桃酸对映异构体的手性识别

对甲基苯胺经甲基化、甲酰化得到5,N,N-三甲基-2-氨基苯甲醛;对L-亮氨酸经酯化、格氏反应得到二齿手性氨基醇.二齿手性氨基醇与上述醛经缩合、还原反应,得到三齿手性氨基醇.产物结构经IR,MS和1H NMR等进行了表征;通过改变主客体的浓度及手性羧酸的纯度,运用1H NMR分别考察了主体二齿手性氨基醇、三齿手性氨基醇对客体布洛芬和扁桃酸对映异构体的手性识别能力.结果表明:当主客体物质的量之比为1:1时,三齿手性氨基醇对布洛芬消旋体的a位甲基质子及扁桃酸消旋体的a位质子分别产生11.2和9.2 Hz的化学位移差值.     

Remote asymmetric trifluoromethylation induced by chiral sulfinyl group: synthesis of enantiomerically pure 1-(2-naphthyl)-2,2,2-trifluoroethanol

The reaction of 1-[(2,4,6-triisopropylphenyl)sulfinyl]-2-naphthaldehyde with (trifluoromethyl)trimethylsilane using tetramethylammonium fluoride gave trifluoromethylated compounds in high yield with high diastereoselectivity. Desilylation and subsequent recrystallization yielded the enantiomerically and diastereomerically pure trifluoroethanol, which afforded chiral 1-(2-naphthyl)-2,2,2-trifluoroethanol after removal of the sulfinyl group.     

Indium-mediated Barbier-type allylation of aldehydes as a convenient method for the highly enantioselective synthesis of homoallylic alcohols

We report a general method for the indium-mediated Barbier-type enantioselective allylation of both aromatic and aliphatic aldehydes using commercially available (1S,2R)-(+)-2-amino-1,2-diphenylethanol as a chiral auxiliary. Using only two equivalents of allyl bromide, excellent yields and very good to excellent enantioselectivities are obtained. To our knowledge, the enantioselectivities reported herein are the highest obtained for indium-promoted allylations of carbonyl compounds.