过渡金属催化不对称C-H键官能团化反应构建轴手性联芳基化合物研究进展

在手性分子中,轴手性化合物占据着非常重要的地位.从原子和步骤经济性方面考虑,利用不对称碳-氢官能团化反应构建轴手性化合物是最简洁高效的方法.随着过渡金属催化的不对称碳-氢键官能团化领域的逐步发展,利用该策略来构建轴手性联芳基化合物的研究成果也不断涌现.本文综述了通过过渡金属钯、铑和铱催化的不对称碳-氢键官能团化反应合成轴手性联芳基化合物的最新进展.此外,还介绍了利用这些方法合成多种轴手性配体及其催化的不对称反应,以及这些方法在天然产物合成中的应用.     

手性膦过渡金属配合物催化不对称交叉偶联反应的研究

自1973年Consiglio和Botteghi首次报道用(一)-DIOP的NiCl_2配合物催化芳基或乙烯基卤代物与仲烷基卤化镁交叉偶联生成光学活性的偶联产物以来,化学家们对不对称交叉偶联反应进行了深入研究。Hayashi等用手性二茂铁膦和手性β-氨基烷基膦的NiCl_2和PdCl_2配合物催化1-苯基乙基氯化     

钯催化偶联-消去法合成芳基末端炔的研究进展

钯催化偶联-消去法合成芳基末端炔的研究进展;芳炔;偶联反应;钯催化剂;合成;综述     

钯催化芳基三氟甲磺酸酯与炔烃的不对称Heck偶联反应

带有轴手性的联烯化合物是一类重要的合成中间体[1],同样存在于各类天然产物和药物中[2].鉴于其重要性,近二十多年来,化学家们报道了各种各样的手性联烯合成方法[3],包括动力学拆分、不对称去对称化、不对称Wittig反应及炔丙基化合物的羧基化等.     

芳基-芳基偶联反应的研究进展

综述了近年来芳基-芳基偶联反应的研究进展, 包括不同类型芳基-芳基偶联反应的特点、机理和应用, 尤其是对立体选择性和区域选择性的偶联方法进行了重点介绍.     

C2轴手性联芳基化合物催化四氢噻喃-4-酮和芳香醛的反应

本文成功合成了4种C_2轴手性联芳基有机催化剂,并将其用于催化四氢噻喃-4-酮和芳香醛的反应。研究表明,当二氯甲烷作为溶剂、芳香醛和四氢噻喃-4-酮的摩尔比为1.2∶5、催化剂I的用量为10(mol)%、反应温度0℃、反应时间20h时,得到较高的产率(85%)及较好的立体选择性(86%)。     

过渡金属催化交叉偶联反应及其在液晶合成中的应用

过渡金属催化交叉偶联反应及其在液晶合成中的应用杜卫红安忠维徐茂梁（西安近代化学研究所西安７１００６１）关键词过渡金属催化交叉偶联反应合成液晶液晶是一类具有特殊物理性能的有机化合物，其分子结构要求长径比大于４，官能团包括芳（杂）环、脂环、烷基、双键、叁...     

手性磷酰胺类化合物不对称催化合成α-芳基丙醇类化合物

对一系列磷酰胺类化合物进行了考察,发现以芳香醛类化合物与二乙基锌作为底物,手性磷酰胺类化合物4a(N-(1R,2R)-2-(异丙基氨基)-1,2-二苯基乙基)-P,P-二苯基次膦酰胺)作为催化剂,通过发生不对称还原反应合成具有生理活性的α-芳基丙醇类化合物.手性磷酰胺类化合物合成所使用的起始物料不仅廉价易得,而且催化效...     

C2轴不对称联芳香化合物的合成研究进展

概述了近年来Ｃ２轴不对称联芳香化合物的合成与不对称偶联的研究进展。     

钯配合物催化的芳基-芳基不对称偶联反应

本文以三种匀性膦作配体制成了零价钯配合物, 并分虽试验了由它们催化苯酚得到的α-溴-β-苄氧基萘和进一步衍生而得的格氏试剂的偶联反应, 制成了β'β'-二苄氧基-α', α'-联萘.     

Chiral Phosphoric Acid Catalyzed Asymmetric Hydrolysis of Biaryl Oxazepines for the Synthesis of Axially Chiral Biaryl Amino Phenol Derivatives

The development of catalytic asymmetric reaction with water as the reactant is challenging due to the reactivity- and stereoselectivity-control issues resulted from the low nucleophilicity and the small size of water. We disclose herein a chiral phosphoric acid (CPA) catalyzed atroposelective ring-opening reaction of biaryl oxazepines with water. A series of biaryl oxazepines undergo the CPA catalyzed asymmetric hydrolysis in a highly enantioselective manner. The key for the success of this reaction is the use of a new SPINOL-derived CPA catalyst and the high reactivity of biaryl oxazepine substrates towards water under acidic conditions. Density functional theory calculations suggest that the reaction proceeds via a dynamic kinetic resolution pathway and the CPA catalyzed addition of water to the imine group is both enantio- and rate-determining.     

Fluxionally Chiral DMAP Catalysts: Kinetic Resolution of Axially Chiral Biaryl Compounds

Can organocatalysts that incorporate fluxional groups provide enhanced selectivity in asymmetric transformations? To address this issue, we have designed chiral 4‐dimethylaminopyridine (DMAP) catalysts with fluxional chirality. These catalysts were found to be efficient in promoting the acylative kinetic resolution of secondary alcohols and axially chiral biaryl compounds with selectivity factors of up to 37 and 51, respectively.     

Chiral Phosphoric Acid-Catalyzed Enantioselective Synthesis of Axially Chiral Compounds Involving Indole Derivatives

Indoles are one of the most ubiquitous subclass of N-heterocycles and are increasingly incorporated to design new axially chiral scaffolds. The rich profile of reactivity and N−H functionality allow chemical derivatization for enhanced medicinal, material and catalytic properties. Although asymmetric C−C coupling of two arenes gives the most direct access of axially chiral biaryl scaffolds, this chemistry has been the remit of metal catalysis and works efficiently on limited substrates. Our group has devoted special interest in devising novel organocatalytic arylation reactions to fabricate biaryl atropisomers. In this realm, indoles and derivatives have been reliably used as the arylation partners in combination with azoarenes, nitrosonapthalenes and quinone derivatives. Their efficient interaction with chiral phosphoric acid catalyst as well as the tunability of electronics and sterics have enabled excellent control of stereo-, chemo- and regioselectivity to furnish diverse scaffolds. In addition, indoles could act as nucleophiles in desymmetrization of 1,2,4-triazole-3,5-diones. This account provides a succinct illustration of these developments.     

Pentanuclear Gold(I) Cluster with an Axially Chiral Biaryl Center: Synthesis and Chiral Transformation

We synthesized and structurally characterized a novel pentanuclear gold(I) cluster by a Ag(I)‐mediated organometallic transformation. The racemic mixture of this pentanuclear gold cluster has been successfully transformed into an enantio‐rich hexanuclear cluster compound by adding adscititious chiral species [Au₂(S‐BINAP)₂]²⁺ (S‐BINAP = (S)‐2,2’‐bis(diphenylphosphino)‐1,1’‐binaphthyl). In this process, a [AuPPh₃]⁺ species in the pentanuclear cluster is replaced by [Au₂(S‐BINAP)₂]²⁺. This strategy represents a new method for the designed construction of chiral metal clusters.     

Synthesis of Axially Chiral QUINAP Derivatives by Ketone-Catalyzed Enantioselective Oxidation

QUINAPs have emerged as a pivotal class of axially chiral compounds with remarkable features in the stereoinduction of diverse enantioselective transformations. However, the confined substrate range and extravagant price still pose challenges, limiting their broader utilization. Herein, we describe the first atroposelective oxidation of an N atom using a chiral ketone catalyst, allowing the kinetic resolution of QUINAPOs to give both the unreacted substrates and their corresponding N-oxides with excellent enantioselectivity. Importantly, the enantioenriched products can be readily converted into the QUINAP targets without any loss of stereochemical integrity. Mechanistic investigations indicate that a dioxirane, generated through the oxidation of the ketone with oxone, acts as the active catalytic species. Furthermore, we have successfully extended this catalytic system to the kinetic resolution of QUINOLs and the dynamic kinetic transformation of pyridine analogues of QUINAPO possessing a labile stereogenic axis. The practicality of the developed protocol is further demonstrated by the successful application of QUINAPO N-oxide as a Lewis base catalyst in a series of enantioselective transformations.     

Organocatalytic Desymmetrization Reactions for the Synthesis of Axially Chiral Compounds

The enantioselective synthesis of atropisomers is an emerging field, that in recent years reached fundamental results and put the bases for innovative applications. Organocatalysis is playing a central role in the realization of original synthesis for novel atropisomeric scaffolds.^[1] In this short review, we would like to highlight the results obtained by our group and others in the field of axially enantioselective desymmetrization reactions using organocatalysis as main strategy.     

Isothiourea-Catalysed Regioselective Acylative Kinetic Resolution of Axially Chiral Biaryl Diols

An operationally simple isothiourea-catalysed acylative kinetic resolution of unprotected 1,1′-biaryl-2,2′-diol derivatives has been developed to allow access to axially chiral compounds in highly enantioenriched form (s values up to 190). Investigation of the reaction scope and limitations provided three key observations: i) the diol motif of the substrate was essential for good conversion and high s values; ii) the use of an α,α-disubstituted mixed anhydride (2,2-diphenylacetic pivalic anhydride) was critical to minimize diacylation and give high selectivity; iii) the presence of substituents in the 3,3′-positions of the diol hindered effective acylation. This final observation was exploited for the highly regioselective acylative kinetic resolution of unsymmetrical biaryl diol substrates bearing a single 3-substituent. Based on the key observations identified, acylation transition state models have been proposed to explain the atropselectivity of this kinetic resolution.     

新的手性配体促进的二芳基二酸和联萘酚的不对称合成

由手性配体α-D-葡萄糖衍生物5，6，7以及薄荷醇（8）和葑醇（9），经 Ulmann偶联反应得到光学活性的（R）－和（S）－6，6′－二硝基联苯－2，2′－ 二甲酸（4a),(R)-6,6′-二甲基联苯－2，2′-二甲酸（4b),(R)-1,1′－联萘－2 ，2′－二甲酸（13）。以三个手性膦酰胺16，17，18和CuCl组成的手性络合物为 催化剂，通过2－萘酚直接氧化偶联得到（S）－2，2′－联萘酚（15）。产物4， 13，15具有中等ee值的光学活性。     

多组分反应合成吡喃衍生物的研究进展

综述了近几年来利用多组分反应合成吡喃衍生物的研究进展,详细地介绍了不同底物参与的反应所需的条件,产率和机理研究,并对其发展方向加以展望.     

Biaryl and Aryl Ketone Synthesis via Pd‐Catalyzed Decarboxylative Coupling of Carboxylate Salts with Aryl Triflates

A bimetallic catalyst system has been developed that for the first time allows the decarboxylative cross‐coupling of aryl and acyl carboxylates with aryl triflates. In contrast to aryl halides, these electrophiles give rise to non‐coordinating anions as byproducts, which do not interfere with the decarboxylation step that leads to the generation of the carbon nucleophilic cross‐coupling partner. As a result, the scope of carboxylate substrates usable in this transformation was extended from ortho‐substituted or otherwise activated derivatives to a broad range of ortho‐, meta‐, and para‐substituted aromatic carboxylates. Two alternative protocols have been optimized, one involving heating the substrates in the presence of Cu^I/1,10‐phenanthroline (10–15 mol %) and PdI₂/phosphine (2–3 mol %) in NMP for 1–24 h, the other involving Cu^I/1,10‐phenanthroline (6–15 mol %) and PdBr₂/Tol‐BINAP (2 mol %) in NMP using microwave heating for 5–10 min. While most products are accessible using standard heating, the use of microwave irradiation was found to be beneficial especially for the conversion of non‐activated carboxylates with functionalized aryl triflates. The synthetic utility of the transformation is demonstrated with 48 examples showing the scope and limitations of both protocols. In mechanistic studies, the special role of microwave irradiation is elucidated, and further perspectives of decarboxylative cross‐couplings are discussed.