有机高价碘化学的研究进展

近年来,有机高价碘试剂的反应性研究获得了迅猛的发展.有机高价碘试剂作为高效、多功能化的氧化剂,通常容易制备且操作简单.与已有的合成方法相比,该类试剂参与的反应表现出了许多独特的优点,并且具有与汞、铬、铅、铊等重金属试剂类似的反应性,但却没有这些试剂所带来的毒性和环境污染问题.藉于此,有机高价碘试剂引起了化学合成工作者们越来越多的关注.综述了我们研究小组在有机高价碘化学领域所取得的研究成果,重点介绍了本课题组开发的新试剂和新的试剂组合在若干转化中的优异表现和独特应用,其中包括下述三个方面:(1)可回收型三价碘试剂iodosodilactone在直接成酯、成酰胺及成肽反应中的首次应用以及由活性更高的iodosodilactone类试剂对-(3,5-双三氟甲基苯基)亚碘酰二内酯(FPID)所介导的高效寡肽液相合成方法;(2)新型水溶性五价碘试剂5-三甲铵基邻碘酰苯甲酸内盐(AIBX)的设计、合成及其反应性探索;(3)对三价碘试剂二氯亚碘酰苯反应性的系统性研究.     

有机三价碘试剂在杂环化合物合成中的应用进展

高价碘化学在过去的30年间经历了突飞猛进的发展.作为一类温和、高效、环境友好的非金属氧化试剂,高价碘化合物尤其是有机三价碘试剂被广泛应用于各种杂环化合物骨架的构建中.综述了有机三价碘试剂介导下不同环系杂环化合物合成的新策略及新方法.     

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.     

2-碘酰基苯甲酸在有机合成中的研究与应用

高价有机碘化合物的反应性质与过渡金属相似,其参与的反应具有反应条件较温和、选择性好、产率高及环境友好等优点,因而近年来关于高价有机碘试剂的研究受到广泛关注,在有机合成领域中获得了较多应用.综述了近年来高价有机碘试剂2-碘酰基苯基酸(IBX)在有机合成中的研究及应用,包括IBX在氧化羟基、含氮化合物和含硫化合物,在制备αβ-不饱和羰基化合物和α,β-不饱和酯,以及在不对称合成等方面的应用.最后介绍了近期对IBX的改进.     

手性高价碘试剂的发展及展望

在过去几十年中，高价碘化学已成为有机化学研究的重要领域.高价碘化合物在多种类型的化学转化中，展现与过渡金属相似的反应性质.而其温和的反应条件、低耗费、环境友好、低毒性等特点，使高价碘化学引起了广泛的研究兴趣，并取得了巨大的进展.手性的高价碘试剂或前体也得以发展并应用于一系列化学计量或催化的不对称反应.近年来，手性高价碘领域研究进展显著，但也存在诸多不足.在本综述中，根据其结构特点以及发展的时间线，对多种类型的手性高价碘试剂和前体做一个总结，这将有助于帮助本领域研究者更好地理解手性高价碘化学的发展以及不足之处.     

芳基碘鎓盐促进芳基化反应的应用

二芳基碘鎓盐属于有机高价碘化合物,具有无毒、反应条件温和以及良好的选择性等优点,在有机合成中具有重要地位,受到广大化学工作者的关注。近年来,利用二芳基碘鎓盐在金属催化下进行的芳基化反应为一些难以合成的杂环化合物的合成提供了简便、高效的方法;同时,二芳基碘鎓盐在无催化剂下进行的芳基化反应,为C—C偶联反应开辟了新的绿色合成路线。本文综述了近年来二芳基碘鎓盐在有机合成中促进芳基化反应的最新进展,着重介绍了利用二芳基碘鎓盐作为芳基化试剂与有机金属试剂、烯烃和炔烃类以及杂环化合物进行芳基化反应的研究;总结了二芳基碘鎓盐与杂环化合物反应中钯催化和铜催化下芳基化反应的机理,最后对二芳基碘鎓盐在今后有机合成中的应用作出了展望。     

有机高价碘化合物在合成中的应用

本文综述了有机高价碘化合物在合成中应用的进展, 介绍了有机高价碘化合物的制备, 阐述了有机高价碘化合物作为芳基, 烷基, 烯基, 炔基, 转移剂及芳基碘盐应用于复杂化合物的合成。     

高价碘试剂的有机电化学合成及应用研究进展

芳基碘化物的阳极氧化是一种绿色高效的用于合成高价碘试剂的方法,该方法用电流代替了化学试剂,避免了使用价格昂贵、反应后处理棘手的氧化剂,如m-CPBA, H_2O_2, Oxone, Selectfluor等.利用电化学合成的高价碘试剂,既可促进氟化、氧化环化等反应,也可成功地应用于天然产物的全合成.一价碘/三价碘氧化还原体系可用来高效地形成碳碳键、碳杂原子等化学键.此外,能回收循环再利用的芳基碘介质可用于间接阳极氟化,且容易和产物分离.总结近年来高价碘试剂的电化学合成方法及其介导的各种化学反应.     

芳基高价碘参与的高速[3,3]-σ重排反应

正Angew. Chem. Int. Ed. 2018, 57, 9078～9082芳基高价碘常被用作芳基亲电试剂、氧化剂或催化剂.反应后,碘原子通常被舍弃.与传统高价碘化学不同,芳基高价碘重排反应实现了芳基高价碘与亲核试剂的偶联.芳基碘官能团在产物中得以保留,为产物的进一步衍生创造了可能.然而,此类反应普遍存在底物范围窄、选择性差、产率低的问题.浙江师范大学化学与生命科学学院彭勃     

单质碘促进的有机反应研究进展

单质碘作为有机化学中结构最为简单的反应试剂之一,其促进的有机转化在最近几年越来越受到人们的关注.总结了单质碘的氧化性,酸性和亲电性3类基本化学性质,并针对3类性质所涉及的相关反应性报道进行了介绍.除此之外,还总结了近5年来单质碘作为催化剂在杂环合成,偶联反应,及C—H官能团转化等方面的应用.     

Hypervalent‐Iodine(III)‐Mediated Oxidative Methodology for the Synthesis of Fused Triazoles

The organic chemistry of hypervalent organoiodine compounds has been an area of unprecedented development. This surge in interest in the use of hypervalent iodine compounds has mainly been owing to their highly selective oxidizing properties, environmentally benign character and commercial availability. Hypervalent iodine reagents have also been used as an alternative to toxic heavy metals, owing to their low toxicity and ease of handling. Hypervalent organoiodine(III) reagents are versatile oxidants that have been successfully employed to extend the scope of selective oxidative transformations of complex organic molecules in synthetic chemistry. This Focus Review concerns the tandem in situ generation and 1,5‐electrocyclization of N‐heteroaryl nitrilimines into fused triazoles. We describe the importance of recently developed hypervalent‐organoiodine(III)‐catalyzed oxidative cyclization reactions, building towards the conclusion that hypervalent iodine chemistry is a promising frontier for oxidative cyclization, in particular of hydrazones, for the synthesis of fused triazoles.     

Iodine(III) mediators in electrochemical batch and flow reactions

The anodic oxidation of aryl iodides is a powerful method for synthesis of hypervalent iodine compounds, which have matured to frequently used reagents in organic synthesis. The electrochemical route eliminates the use of expensive or hazardous oxidants for their synthesis. Hypervalent iodine reagents generated at the anode are successfully used as either in-cell or ex-cell mediators for many valuable chemical transformations including fluorinations and oxidative cyclisations. The recent advances in the area of flow electrochemistry are providing additional benefits and allow new synthetic applications. Mechanistic insights and novel technologies enable the development of new concepts for sustainable chemistry.     

Hypervalent iodine chemistry in synthesis: scope and new directions

The impressive development of hypervalent iodine chemistry in recent years is reflected by the number of publications in this area. Although the synthesis of the first hypervalent iodine compound dates back more than 100 years, the investigation of the reactivities of these compounds and their efficient use as metal-free reagents in organic synthesis is still ongoing. This contribution summarizes recent achievements and highlights key findings and developments that will influence future research and lead to novel applications of hypervalent iodine reagents in synthesis.     

Cyclic Haloiodanes: Syntheses,Applications and Fundamental Studies

Hypervalent iodine reagents are powerful tools in contemporary organic synthesis. They have found numerous applications in modern oxidative transformations. The unique reactivity of hypervalent iodine allows access to unconventional electrophilic synthons. For example, electrophilic halogenation chemistry has been greatly expanded by the study of various haloiodanes. Cyclic λ³-haloiodanes are versatile reagents which can promote reactions such as halogenations, halocyclizations and oxidations. Their peculiar reactivity sets them apart from traditional sources of electrophilic halogens. Furthermore, they offer a broad range of reactivities which have been exploited in more diversified transformations. This review summarizes the different syntheses and derivatives of these cyclic haloiodanes, their applications and mechanistic insights as well as the relevant computational, structural and kinetic studies.     

Hypervalent Iodine‐Catalyzed Oxidative Functionalizations Including Stereoselective Reactions

Hypervalent iodine chemistry is now a well‐established area of organic chemistry. Novel hypervalent iodine reagents have been introduced in many different transformations owing to their mild reaction conditions and environmentally friendly nature. Recently, these reagents have received particular attention because of their applications in catalysis. Numerous hypervalent iodine‐catalyzed oxidative functionalizations such as oxidations of various alcohols and phenols, α‐functionalizations of carbonyl compounds, cyclizations, and rearrangements have been developed successfully. In these catalytic reactions stoichiometric oxidants such as mCPBA or oxone play a crucial role to generate the iodine(III) or iodine(V) species in situ. In this Focus Review, recent developments of hypervalent iodine‐catalyzed reactions are described including some asymmetric variants. Catalytic reactions using recyclable hypervalent iodine catalysts are also covered.     

Chiral Hypervalent Iodine Reagents: Synthesis and Reactivity

Chiral hypervalent iodine chemistry has been steadily increasing in importance in recent years. This review catalogues enantioselective transformations triggered by chiral hypervalent iodine(III/V) reagents, in stoichiometric or catalytic quantities, highlighting the different reactivities in terms of yield and enantioselectivity. Moreover, the synthesis of the most remarkable and successful catalysts has been illustrated in detail.     

Vicinal Difunctionalization of Alkenes with Iodine(III) Reagents and Catalysts

Hypervalent iodine(III) reagents have been known for over a century, and their reaction profile is still actively investigated. Recent years have seen impressive improvements in the area of alkene difunctionalization reactions, where new methodologies have become available. Especially chiral non‐racemic hypervalent iodine(III) reagents and catalysts have emerged as versatile tools for the realization of important enantioselective transformations.     

Highly stereoselective metal-free oxyaminations using chiral hypervalent iodine reagents

The ring and I: Hypervalent iodine compounds avoid the issues of toxicity or complicated ligands of many transition-metal-based systems. A highly enantioselective oxyamination of alkenes with N-sulfonyl ureas employing chiral, lactic acid-based hypervalent iodine reagents gives a facile synthesis of enantiomerically pure 2-arylproline derivatives for the first time.     

Reactivity of Hypervalent Iodine(III) Reagents Bearing Transferable N-Based Groups

Hypervalent iodine reagents have the ability of inverting the polarity of functional groups bound to iodine, a reactivity known as umpolung. This reactivity makes hypervalent iodine compounds highly attractive for the creation of electrophilic synthons of known nucleophiles, resulting in novel synthetic disconnections and the formation of new Nu(nucleophile)−N bond. Electrophilic sources of nitrogen-based groups have been known for many decades and are of great synthetic importance. Traditionally, these reagents are limited to few examples. With the use of hypervalent iodine, the transfer of a wide diversity of nitrogen sources became a possibility. This review compiles the latest reported examples of hypervalent iodine reagents capable of electrophilic transfer of nitrogen-based groups. It showcases the preparation of such reagents, their synthetic utility, and reaction mechanisms involving these group transfer reagents.     

The applications of hypervalent iodine(III) reagents in the constructions of heterocyclic compounds through oxidative coupling reactions

Hypervalent iodine(Ⅲ)reagents have been vastly used in many useful organic transformations.In this review article,we highlight the strategies that used the common hypervalent iodine(Ⅲ)reagents as oxidants to synthesize the heterocyclic compounds,based on the patterns of bond formation during the construction of the heterocyclic backbones.