手性高价碘试剂诱导的烯烃不对称官能团化反应研究进展

手性高价碘试剂诱导的烯烃官能团化是获得对映体富集的手性分子和具有生物活性天然产物的基本方法,是不对称合成中一个崭新且富有成效的领域之一.纵观20年来该领域的发展,在手性高价碘诱导下,一方面通过分子间的官能团化实现了双键的双磺酰氧基化、双乙酰氧基化、双卤化、双胺化、羟基化-磺酰氧基化、卤化-烷基化及羰基化等,对映选择性地...     

有机五价碘氧化试剂

介绍了最近几年有关五价碘氧化试剂在有机合成中应用的研究进展,主要从合成、应用、机理方面进行了阐述。     

金刚烷负载高价碘试剂的合成及氧化反应活性

以1,3,5,7-四氨基金刚烷与4-碘苯基酰氯为原料,经酰化、氧化反应,制备了新型金刚烷负载的高价碘试剂(1a-1c)。 酰化反应以CH₂Cl₂为溶剂,首先,0 ℃,反应4 h,然后室温反应2 h,投料比n(1,3,5,7-四氨基金刚烷)∶n(4-碘苯基酰氯)∶n(三乙胺)=1∶4.4∶5.2。 氧化反应以CH₂Cl₂/醋酸(体积比1∶1)为溶剂,间氯过氧苯甲酸(m-CPBA)为氧化剂,室温反应12 h,投料比n(2)∶n(m-CPBA)=1∶12。 化合物1a,1b和1c的总收率分别为86.4%、85.4%和85.3%。 以化合物1a-1c为氧化剂,在四甲基哌啶氮氧化物(TEMPO)催化下各类醇被氧化成相应的醛或酮,产物收率87%~100%。 负载碘苯2a-2c可以被方便地分离和回收,平均回收率98%,可再经氧化,高收率转化成化合物1a-1c,循环利用。     

三价碘有机物在有机合成中的应用

单质碘可形成很多多价碘的化合物。其中三价碘及五价碘的有机或无机物,应用最多。这些化合物的性质,结构、制备方法,都有了详尽的报道及综述。然而,它们被大量应用于有机合成中,作为有用的有机合成中间体却是最近才有见报道。A.Varvoglis曾详细报道了一些多价碘物的合成方法,结构、性质及其在合成上的一些应用。本文将着重介绍下列五种三价碘化合物在有机合成中的一些应用:     

可再生高价碘试剂4-二氯碘苯甲酸的合成及其氧化性能

以对碘苯甲酸为原料,采用“一锅法”合成高价碘试剂4-二氯碘苯甲酸（1）,其结构经¹H NMR和IR确证。考察了其对取代苯甲醇的氧化性能。结果表明：1对4-(二甲氨基)苄醇的氧化性能最高,收率93%。     

可再生型高价碘试剂亚碘酰二内酯在高效醇氧化中的应用研究

利用商品化的高价碘试剂亚碘酰二内酯(Iodosodilactone)作为最终氧化剂, 配合催化量的氮氧自由基2,2,6,6-四甲基哌啶-1-氧自由基(TEMPO)和当量的4-二甲氨基吡啶(DMAP)所组成的反应体系可以将含有不同官能团的伯醇快速高效地氧化为相应的醛且不会发生过度氧化; 将反应体系中的催化剂换为空间位阻较小的氮氧自由基1-甲基-2-金刚烷氮氧自由基(1-Me-AZADO)则可以将仲醇高效地氧化为相应的酮. 值得指出的是, 反应结束后Iodosodilactone的还原态2-碘-间苯二甲酸和DMAP可以通过简单的过滤及酸碱中和处理进行回收, Iodosodilactone的再生可通过用次氯酸钠/盐酸体系氧化2-碘-间苯二甲酸来高效实现.     

高价碘氧化醇的研究进展

概括了几种常用的三价和五价碘试剂作为氧化剂氧化醇的研究进展, 并对相应的氧化机制进行了探讨.     

原位生成的高价碘试剂在有机合成中的应用进展

原位生成的高价碘试剂具有原子经济性、性能温和和绿色环保等优点,在诸多合成和不对称催化等反应中表现活跃.详细介绍了原位生成高价碘的概念以及反应机理,根据不同的反应类型分别对原位生成的三价碘、五价碘以及手性高价碘试剂在有机合成反应中的应用进行了归纳总结,分析了原位生成的高价碘试剂目前面临的问题,并对今后的发展趋势作了展望.     

烯胺酮α-官能团化反应的研究进展

烯胺酮是一类非常重要的有机合成砌块,具有易获得、储存方便、反应多样性等优点.更重要的是,烯胺酮是许多杂环化合物的重要前体.最近,通过C—H活化对烯胺酮进行过渡金属催化或无过渡金属的α-官能团化反应已成为构建官能化烯胺酮或杂环化合物的一种更为原子和步骤经济的策略,并引起了许多有机化学家的关注.根据成键类型,该综述分为五个部分:C—C键的形成、C—O键的形成、C—N键的形成和C—X键的形成以及C—S/C—Se键的形成.主要对烯胺酮α位官能团化反应进行了综述,从反应机理、反应体系、底物范围等角度系统地综述了烯胺酮α位官能团化反应的进展.     

Palladium-Catalyzed Organic Reactions Involving Hypervalent Iodine Reagents

The chemistry of polyvalent iodine compounds has piqued the interest of researchers due to their role as important and flexible reagents in synthetic organic chemistry, resulting in a broad variety of useful organic molecules. These chemicals have potential uses in various functionalization procedures due to their non-toxic and environmentally friendly properties. As they are also strong electrophiles and potent oxidizing agents, the use of hypervalent iodine reagents in palladium-catalyzed transformations has received a lot of attention in recent years. Extensive research has been conducted on the subject of C—H bond functionalization by Pd catalysis with hypervalent iodine reagents as oxidants. Furthermore, the iodine(III) reagent is now often used as an arylating agent in Pd-catalyzed C—H arylation or Heck-type cross-coupling processes. In this article, the recent advances in palladium-catalyzed oxidative cross-coupling reactions employing hypervalent iodine reagents are reviewed in detail.     

Oxidation of BINOLs by Hypervalent Iodine Reagents: Facile Synthesis of Xanthenes and Lactones

Xanthene derivatives have broad applications in medicines, fluorescent probes, dyes, food additives, etc. Therefore, much attention was focused on developing the synthetic methods to prepare these compounds. Binaphthyl-based xanthene derivatives were prepared through the oxidation of BINOLs promoted by the hypervalent iodine reagent iodosylbenzene (PhIO). Nine-membered lactones were obtained through a similar oxidative reaction when iodoxybenzene (PhIO₂) was used. Additionally, one-pot reactions of BINOLs, PhIO and nucleophiles such as alcohols and amines were also investigated to provide alkoxylated products and amides in good to excellent yields.     

Late-Stage Dehydroxyazidation of Alcohols Promoted by Trifunctional Hypervalent Azido-Iodine(III) Reagents

The development of convenient new methods for the synthesis of organic azides is highly desirable. Herein, we report a practical method for dehydroxyazidation of alcohols via an S_N2 pathway involving PPh₃ and trifunctional benziodazolone-based hypervalent azido-iodine(III) reagents, which function as an electrophilic center, an azido source, and a base. This mild, chemoselective method was used for late-stage azidation of structurally complex alcohols, as well as for a new synthetic route to the antiepileptic drug rufinamide. The reaction mechanism was also investigated both experimentally and computationally.     

分子碘催化的有机反应研究进展

综述了近几年来分子碘作为催化剂在有机合成中的应用研究. 碘催化的有机反应主要涉及引入保护基团的反应、去保护基团的反应、碳-碳键的形成反应以及杂环化合物的反应等.     

Synthesis and Structure of Hypervalent Iodine(III) Reagents Containing Phthalimidate and Application to Oxidative Amination Reactions

A new class of hypervalent iodine reagents containing phthalimidate was synthesized, and structurally characterized by X‐ray analysis. The benziodoxole‐based reagent displays satisfactory solubility in common organic solvents and is reasonably stable in solution as well as in the solid state. The reagent was used for the oxidative amination of the C(sp³)? H bond of N,N‐dimethylanilines. In addition, the reagent was also applicable to oxidative amination with rearrangement of trialkylamines as well as enamines that were prepared in situ from secondary amines and aldehydes.     

Asymmetric Syntheses Promoted by Organoselenium Reagents

Using chiral nonracemic electrophilic-organoselenium-reagents-asymmetric alkoxy-, hydroxy-, azido- and amido-selenenylation of alkenes were effected with high diastereoselectivity. These reagents have also been employed in catalytic amounts to promote one-pot selenenylation-deselenenylation processes. The asymmetric cyclization of properly substituted alkenes diastereoselectively afforded lactons, tetrahydrofurans oxazolines, thiazolines, pyrrolidines, isoxazolidines, 1,2-oxazines, and cyclic nitrones. Enantiopure dioxane, morpholine, tetrahydrofuran, oxazolidin-2-one and aziridine derivatives were prepared from alkenes, PhSeX, and optically active nucleophiles or substrates.     

Continuous‐Flow Electrochemical Generator of Hypervalent Iodine Reagents: Synthetic Applications

An efficient and reliable electrochemical generator of hypervalent iodine reagents has been developed. In the anodic oxidation of iodoarenes to hypervalent iodine reagents under flow conditions, the use of electricity replaces hazardous and costly chemical oxidants. Unstable hypervalent iodine reagents can be prepared easily and coupled with different substrates to achieve oxidative transformations in high yields. The unstable, electrochemically generated reagents can also easily be transformed into classic bench‐stable hypervalent iodine reagents through ligand exchange. The combination of electrochemical and flow‐chemistry advantages largely improves the ecological footprint of the overall process compared to conventional approaches.     

Cyclic Hypervalent Iodine Reagents for Atom‐Transfer Reactions: Beyond Trifluoromethylation

Hypervalent iodine compounds are privileged reagents in organic synthesis because of their exceptional reactivity. Among these compounds, cyclic derivatives stand apart because of their enhanced stability. They have been widely used as oxidants, but their potential for functional‐group transfer has only begun to be investigated recently. The use of benziodoxol(on)es for trifluoromethylation (Togni's reagents) is already widely recognized, but other transformations have also attracted strong interest recently. In this Review, the development in the area since 2011 will be presented. After a short summary of synthetic methods to prepare benziodoxol(on)e reagents, their use to construct carbon–heteroatom and carbon–carbon bonds will be presented. In particular, the introduction of alkynes by using ethynylbenziodoxol(on)e (EBX) reagents has been highly successful. Breakthroughs in the introduction of alkoxy, azido, difluoromethyl, and cyano groups will also be described.     

烷基锌与亚胺不对称加成反应的研究进展

综述了烷基锌与亚胺不对称加成反应的最新进展。参考文献31篇。