5-羟基色胺受体激动剂(1R,2S)-(-)-2-(2-羟基苯基)-N,N-二丙基环丙胺的不对称合成

利用手性双唑啉与三氟甲磺酸亚铜催化2-甲氧基苯乙烯与重氮乙酸二环己基甲酯的不对称环丙烷化反应合成了手性环丙烷羧酸酯,用氢氧化钠对其进行选择性水解得到全反式环丙烷羧酸,其ee值经GC测定为88%.进一步经过Curtius重排、烷基化等反应及重结晶等步骤合成了光学纯的具有生理活性的环丙胺化合物1a和1b.     

推-拉电子体系环丙烷的不对称合成及其对映选择性开环/环化反应研究进展

含有推-拉电子(DA)体系的张力环化合物,例如DA环丙烷,是非常有用的合成砌块,被应用于天然产物全合成以及合成具有生物活性的分子的研究中。 近年来,本课题组利用手性铜、镍等配合物为催化剂,一方面发展了一系列高效合成手性DA环丙烷的新方法;另一方面陆续实现了仲胺、醇、硝酮、氮杂亚胺叶立德、烯醇硅醚、吲哚等多种亲核试剂与DA环丙烷的高对映选择性开环/环化反应。 本文结合我们课题组工作综述了DA环丙烷化合物的不对称合成、开环/环化反应以及动力学拆分方面的主要研究进展并进行了展望。     

5—羟基色胺受体激动剂（1R,2S）—（一）—2—（2—羟基苯基）—N …

利用手性双哑唑啉与三氟甲磺酸亚铜催化２－甲氧基苯乙烯与重氮乙酸二环己基甲酯的不对称环丙烷化反应合成了手性环丙烷羟酸酯,用氢化氧钠对其进行选择性水解得到全反式环丙烷羟酸,其ｅｅ值ＧＣ测定为８８％。进一步经过Ｃｕｒｔｉｕｓ重排、烷基化等反应及重结晶等步骤合成了光学纯的具有生理活性的环丙胺化合物Ｉａ和Ｉｂ。     

铜和铁催化吲哚的不对称分子内环丙烷化

正J.Am.Chem.Soc.2017,139,7697~7700吲哚是天然产物中广泛存在的杂环结构,发展构建吲哚骨架的手性多环化合物的方法一直备受关注.过渡金属催化的分子内不对称环丙烷化反应能够从简单的线性底物合成具有复杂稠环结构的手性分子.人们已经成功将过渡金属催化吲哚的非对映选择性分子内环丙烷化反应应用于多种吲哚生物碱的高效合成,然而这类反应的对映选择性     

1,1′-联萘-2,2′-二胺的合成及在不对称合成中的应用

综述了 1,1′ 联萘 2 ,2′ 二胺 (联萘胺 )化合物的制备 ,讨论了它们作为手性辅助基或配体在烯烃、酮、亚胺的不对称氢化及在烯烃的不对称环丙烷化、醛的烷基化反应、醛的不对称烯丙基化反应、不对称烯丙位取代反应和不对称Diels Alder反应等反应中的应用 .     

新手性源5-(1-(艹孟)氧基)-3-溴-2(5H)-呋喃酮的不对称双Michael加成/分子内亲核取代反应的研究

新型手性试剂的合成及其在不对称和天然产物合成中的应用乃是当今有机化学中非常活跃的研究领域。近几年来,利用天然手性助剂薄菏醇、冰片制备具有重要合成价值的手性源,用于不对称反应以及立体选择性合成某些生物活性化合物引起人们重视。在以往研究工作的基础上,我们深入研究了具有独特结构性能的5-(l-(艹孟)氧基)-3-溴-2(5H)-呋喃酮新手性源(5a)的合成方法及其串联的双Michael加成/分子内亲核取代反应。3-溴呋喃酮新手性试剂5a制备方法简便,化学产率较髙,光学纯度单一。由于5-(1-(艹孟)氧基)-3二溴呋喃酮5a具有独特的结构性能,它可以作为稳定的Michael受体,能够发生串联的双Michael加成/分子内亲核取代反应。同时,由于(艹孟)氧基的立体专一性控制,生成了一般合成方法难以合成的手性的丁内酯并螺-环丙烷类化合物。此新手性源的合成及其不对称螺-环丙化反应的研究,为进一步合成一系列新的光学活性环丙烷化合物提供了简便有效的途径。     

1，1′－联萘－2，2′－二胺的合成及在不对称合成中的应用

综述了1，1′－联萘－2，2′－二胺（联萘胺）化合物的制备，讨论了它们作 为手性辅助基或配体在烯烃、酮、亚胺的不对称氢化及在烯烃的不对称环丙烷化、 醛的烷基化反应、醛的不对称烯丙基化反应、不对称烯丙位取代反应和不对称 Diels-Alder反应等反应中的应用。     

手性金属催化剂在不对称环丙烷化反应中的应用进展

手性金属催化剂在不对称环丙烷化反应中的应用一直是不对称合成领域的一个热点。对三十多年来的这一领域的手性金属催化剂的发展作了详细的归纳和评述。     

手性胺膦配体在不对称催化中的应用

利用邻二苯基膦苯甲醛分别与多种手性二胺的缩合反应,设计合成了一系列新型手性四齿胺膦配体.这类多齿胺膦配体含有两个软的磷原子和两个硬的氮原子,具有丰富的配位化学性能和优秀的不对称诱导能力.本文综述了手性胺膦金属络合物催化剂在不对称转移氢化反应、氧化动力学拆分反应、烯烃的不对称环氧化反应和不对称环丙烷化反应、不对称D-A反应中的应用.     

手性pybox-金属络合物及其在不对称催化反应中的应用

具有C2对称性的双噁唑啉型吡啶(pybox)是一类有效的手性配体,能与许多金属离子配位,其手性催化性能已得到越来越多的关注。本文综述了手性配体pybox和pybox-金属络合物的合成方法,特别是近年来pybox-金属络合物在不对称催化反应如不对称环丙烷化反应、不对称Diels-Alder反应、1,3-偶极环加成反应、不对称aldol反应等中应用的最新进展。     

Palladium-catalyzed oxidative activation of arylcyclopropanes

Palladium chloride-catalyzed intramolecular activation of electroneutral cyclopropane derivatives results in cleavage of the cyclopropane ring followed by formation of heterocyclic derivatives. Phenols, carboxylic acids, and amide groups were considered as substituents ortho to the cyclopropane ring in this catalytic activation chemistry. The regioselectivity observed in the case of amide-containing substrates was different from that of carboxylic acid-containing substrates, ruling out simple cyclopropane isomerization followed by a Wacker oxidation as the mechanistic pathway. [reaction: see text]     

Stereoselective Synthesis of cis-2 and trans-2-(Indol-3-yl) Cyclopropyl Amines,Carboxylic Acids,and Esters

We report a general route for the synthesis of E and Z isomers of indol-3-yl cyclopropyl amines, carboylic acids, and esters. These cyclopropane containing molecules are of interest as conformationally constrained analogues of tryptamine and indole propionic acid, biologically active indoles. The route involves reaction of vinyl indole with ethyl diazoacetate, chromatographic separation of the E and Z stereoisomers of the resulting cyclopropane esters, hydrolysis to form the E and Z cyclopropane acids, and formation of amines by the Curtius reaction.     

Gold(I)-catalyzed intermolecular addition of carbon nucleophiles to 1,5- and 1,6-enynes

Gold(I)-catalyzed addition of carbon nucleophiles to 1,6-enynes gives two different type of products by reaction at the cyclopropane or at the carbene carbons of the intermediate cyclopropyl gold carbenes. The 5-exo-dig cyclization is followed by most 1,6-enynes, although those bearing internal alkynes and alkenes react by the 6-endo-dig pathway. The cyclopropane versus carbene site-selectivity can be controlled in some cases by the ligand on the gold catalyst. In addition to electron-rich arenes and heteroarenes, allylsilanes and 1,3-dicarbonyl compounds can be used as the nucleophiles. In the reaction of 1,5-enynes with carbon nucleophiles, the 5-endo-dig pathway is preferred.     

Silylium‐Ion‐Promoted (5+1) Cycloaddition of Aryl‐Substituted Vinylcyclopropanes and Hydrosilanes Involving Aryl Migration

A transition‐metal‐free (5+1) cycloaddition of aryl‐substituted vinylcyclopropanes (VCPs) and hydrosilanes to afford silacyclohexanes is reported. Catalytic amounts of the trityl cation initiate the reaction by hydride abstraction from the hydrosilane, and further progress of the reaction is maintained by self‐regeneration of the silylium ions. The new reaction involves a [1,2] migration of an aryl group, eventually furnishing 4‐ rather than 3‐aryl‐substituted silacyclohexane derivatives as major products. Various control experiments and quantum‐chemical calculations support a mechanistic picture where a silylium ion intramolecularly stabilized by a cyclopropane ring can either undergo a kinetically favored concerted [1,2] aryl migration/ring expansion or engage in a cyclopropane‐to‐cyclopropane rearrangement.     

Visible‐Light Photocatalytic Intramolecular Cyclopropane Ring Expansion

Described herein is a new visible‐light photocatalytic strategy for the synthesis of enantioenriched dihydrofurans and cyclopentenes by an intramolecular nitro cyclopropane ring expansion reaction. Mechanistic studies and DFT calculations are used to elucidate the key factors in this new ring expansion reaction, and the need for the nitro group on the cyclopropane.     

Aryl vinyl cyclopropane Cope rearrangements

While the divinyl cyclopropane Cope rearrangement is well-known, and has been broadly applied in synthesis, examples of the aryl vinyl cyclopropane Cope rearrangement are less common and generally limited in scope or reaction yield. The aryl vinyl cyclopropane Cope rearrangement gives access to the benzocycloheptene scaffold, which is present in a variety of naturally occurring and medicinally relevant products. Herein we report a method to obtain either of two regioisomeric benzocycloheptene products via an aryl vinyl cyclopropane Cope rearrangement, featuring additive-controlled regioselectivity. Mechanistic studies indicate a dynamic equilibration of cyclopropane stereoisomers, followed by rearrangement of the cis diastereomer.     

Visible-Light Photocatalytic Intramolecular Cyclopropane Ring Expansion

Described herein is a new visible-light photocatalytic strategy for the synthesis of enantioenriched dihydrofurans and cyclopentenes by an intramolecular nitro cyclopropane ring expansion reaction. Mechanistic studies and DFT calculations are used to elucidate the key factors in this new ring expansion reaction, and the need for the nitro group on the cyclopropane.     

环丙烷衍生物在D2O离子体系中的H/D交换反应

在D2O化学反应气条件下研究了环丙烷衍生物的H/D交换反应特性.发现了三种新的产物离子[M+1]+、[M+2]+和[M+3]+.应用碰撞诱导碎裂(CID)技术研究了这些离子的碎裂反应特性.实验结果表明三种新的产物离子是由反应物与试剂离子之间发生H/D交换反应生成的.并获得了环丙烷衍生物结构中活泼氢位置及其数量的信息.     

Bromination of exo-Tricyclo[3.2.2.0(2,4)]non-6-ene

In carbon tetrachloride reaction of 1 with bromine occurs at the double bond and is favored from the less hindered face, anti to the cyclopropane ring, to give 2 and 3 (2:1) over reaction from the syn face or at the corner of the cyclopropane to give 5. In the solvent methanol, corner attack of bromine at the cycloproane to give 30, 16, 17, and 37 competes with reaction at the double bond anti to the cyclopropane to give 18, 19, and 2.     

Nitrile anion cyclization with epoxysilanes followed by brook rearrangement/ring opening of cyclopropane nitriles/alkylation

The reaction of delta-silyl-gamma,delta-epoxypentanenitrile derivatives with a base and an alkylating agent affords delta-siloxy-gamma,delta-unsaturated pentanenitrile derivatives via a tandem process that involves the formation of the cyclopropane derivative by epoxy nitrile cyclization followed by Brook rearrangement and an anion-induced cleavage of the cyclopropane ring.