三乙胺三(氟化氢)在有机合成中的应用

氟化反应在有机合成中有着广泛的应用, 三乙胺三(氟化氢)作为氟化试剂有着其它氟化试剂所无法比拟的优越性. 对近年来三乙胺三(氟化氢)在有机合成中的应用进行了总结和概述, 重点介绍了亲核取代、环氧开环反应、亲电加成反应和脱硅保护基等反应.     

有机化合物氟化反应的研究进展

有机氟化物具有独特的物理、化学性质及生理活性，在医学、农业化学、材料科学等领域引起了广泛关注。本文综述了氟气直接氟化、Balz-Schiemann反应、亲核氟化、亲电氟化和自由基氟化等氟化反应的优缺点，旨在为相关有机氟化物的化学合成提供新思路。     

离子液体在氟化反应中的应用进展

离子液体作为一类新型绿色溶剂,具有制备简单、稳定性好、溶解能力强、挥发性小、安全性强等优点,因此在有机单元反应包括酯化、氧化、还原、重排反应等中的应用相当广泛,有着十分诱人的应用前景.虽然其在氟化反应中的应用研究开始得较晚,但发展很快,目前在重氮化氟化、亲核氟化、亲电氟化以及电化学氟化等方面都取得了较大的进展.本文综述了近年来离子液体在氟化反应中应用的最新进展情况,并对其未来发展方向和应用前景进行了展望.     

电化学部分氟化芳基研究进展

含氟芳香化合物具有生物活性好、稳定性高、易被生物体代谢等优点,在医药和农药领域有着广泛的用途.目前芳基部分氟化的方法主要分为依赖于氟化试剂的亲电氟化方法以及反应条件苛刻甚至需要过渡金属催化的亲核氟化方法,这些方法操作繁琐并且污染环境.电化学氟化将"电能"作为一种"强氧化剂"来实现氟化反应,是一种直接、绿色且温和的氟化手...     

对映选择性亲电氟化反应研究进展

含氟有机化合物, 特别是手性氟化物在医药、农药及功能性材料等相关领域的作用备受注目. 尽管在分子中有立体选择性地引入一个氟原子一直是有机化学家面临的一个挑战性问题, 近年来在化学家们的不断努力下, 对映选择性氟化反应研究取得重要进展. 高光学活性的手性氟化物可通过手性亲电氟化试剂诱导的立体选择性氟化反应, 基于底物的手性氟化反应以及手性催化剂诱导的不对称催化氟化反应等来制备. 特别是, 手性金属配合物和有机催化剂诱导的不对称催化氟化反应被广泛应用于各类手性氟化物的合成, 已成为不对称氟化反应研究的热点. 全面介绍对映选择性亲电氟化反应研究概况和最新进展, 讨论各种不对称氟化反应的特点及应用范围.     

高价碘试剂介导的8-氨基喹啉C(5)位碳-氢键亲核氟化反应

8-氨基喹啉的C(5)位碳-氢键氟化反应近年来受到广泛关注,但大多需要使用过渡金属催化剂和亲电氟化试剂来实现.在高价碘试剂的介导下实现了无过渡金属催化条件下的8-氨基喹啉C(5)位碳-氢键亲核氟化反应.使用廉价易得且安全稳定的氟化银作为亲核氟化试剂,反应无需惰性气体保护,条件简单,操作方便,区域选择性好,底物范围较广,为喹啉类化合物的氟化提供了一种有潜在应用价值的新方法.     

不同氨基保护下的α-羟基-γ-氨基磷酸酯的氟化反应

比较了不同氨基保护基对α-羟基-γ-氨基磷酸酯亲核氟化反应的影响,以 Boc, Ts和Bz保护氨基时未得到预期的氟化产物;以Phth, Fmo和CH3OCO-保护氨基时可得到氟化产物,其中Phth保护氨基的效果最好,氟化产物的收率42%     

亲核性氟源在碳碳不饱和键选择性氟化官能化反应中的应用

含氟化合物表现出的特殊理化和生物活性使得其在药物、农用化学品和材料科学等领域有着广泛而重要的应用,因此,含氟化合物的高效制备不仅成为了合成化学的研究热点之一,而且极大地推动了相关领域的蓬勃发展.其中,在有机分子内直接引入氟原子的方法主要有亲电氟化和亲核氟化.相较于亲电氟化,亲核氟化反应所用的氟化试剂通常廉价易得,所需的反应条件也比较温和.作者课题组借助过渡金属催化、可见光氧化还原催化和可见光促进策略,拓展了亲核性氟源在碳碳不饱和键选择性氟化官能化反应中的应用,合成了一系列结构新颖的含氟化合物.在该研究评论中将对此做出小结,并对该领域值得关注的研究方向进行简要的展望.     

有机分子中引入二氟亚甲基方法的最新进展

本综述从直接氟化法和间接氟化法两个方面就近些年来在有机化合物中引入二氟亚甲基的方法进行了概括。直接氟化法中，主要介绍了利用亲核和亲电两类氟化试剂在分子中导入-CF~2-的一些最新进展；间接氟化法则主要介绍了一些新的含-CF~2-的合成砌块在合成二氟亚甲基化合物中的应用。     

微波辅助离子液体合成法在亲核氟化中的应用

采用微波辅助合成法快捷、高效地制备了系列咪唑类和吡啶类离子液体,并对其在亲核氟化中的应用进行了研究.结果表明,N-苄基吡啶四氟硼酸盐([bepy]BF4)是一种稳定性高、使用效果好的离子液体.在微波作用下,以N-苄基吡啶四氟硼酸盐和乙腈为共溶剂,以氟化铯为氟化试剂,高效合成了系列含氟化合物.在优化反应条件下,其收率为54.1%～76.3%,反应时间较常规油浴加热最好时可缩短50%以上.     

Selectfluor: Mechanistic Insight and Applications

The replacement of hydrogen atoms with fluorine substituents in organic substrates is of great interest in synthetic chemistry because of the strong electronegativity of fluorine and relatively small steric footprint of fluorine atoms. Many sources of nucleophilic fluorine are available for the derivatization of organic molecules under acidic, basic, and neutral conditions. However, electrophilic fluorination has historically required molecular fluorine, whose notorious toxicity and explosive tendencies limit its application in research. The necessity for an electrophilic fluorination reagent that is safe, stable, highly reactive, and amenable to industrial production as an alternative to very hazardous molecular fluorine was the inspiration for the discovery of selectfluor. This reagent is not only one of the most reactive electrophilic fluorinating reagents available, but it is also safe, nontoxic, and easy to handle. In this Review we document the many applications of selectfluor and discuss possible mechanistic pathways for its reaction.     

A convenient method for the synthesis of fluorinated α-cyanoacetates via phase-transfer catalysis

A simple and convenient method for the synthesis of fluorinated α-cyanoacetate derivatives has been developed by using electrophilic fluorination of allyl and benzyl substituted α-cyanoacetates with N-fluorobenzensulfonimide (NFSI) as electrophilic fluorinating agent via phase transfer catalysis. The reaction is transition metal free and carried out in aqueous and mild reaction conditions in the presence of readily available tetra-N-butylammonium iodide (TBAI) as phase-transfer catalyst.     

Retracted: A Facile Synthetic Route to New Fluorinated Building‐Blocks of 1‐Fluoroalkynes and 1‐Fluorodiynes

A facile and direct fluorination process of alkynes and diynes was developed. In the presence of n‐butyllithium, the reaction of a series of terminal alkynes and diynes with the electrophilic fluorinating reagent (NFSI) proceeded to afford various 1‐fluoroalkynes and 1‐fluoro‐1,3‐diynes in moderate to high yields.     

Ultrafast Click Chemistry with Fluorosydnones

We report the synthesis and reactivity of 4‐fluorosydnones, a unique class of mesoionic dipoles displaying exquisite reactivity towards both copper‐catalyzed and strain‐promoted cycloaddition reactions with alkynes. Synthetic access to these new mesoionic compounds was granted by electrophilic fluorination of σ‐sydnone Pd^II precursors in the presence of Selectfluor. Their reactions with terminal and cyclic alkynes were found to proceed very rapidly and selectively, affording 5‐fluoro‐1,4‐pyrazoles with bimolecular rate constants up to 10⁴ m ^?1 s^?1, surpassing those documented in the literature with cycloalkynes. Kinetic studies were carried out to unravel the mechanism of the reaction, and the value of 4‐fluorosydnones was further highlighted by successful radiolabeling with [¹⁸F]Selectfluor.     

Screening of chiral catalysts for enantioselective electrophilic fluorination of β-ketoesters

A variety of oxygen- and nitrogen-containing chiral ligands in combination with various metals have been screened in the enantioselective electrophilic fluorination of β-ketoesters. This study involved the use of readily available substrates, chiral ligands and electrophilic fluorinating agents. In particular, heterobimetallic Al-Li-BINOL complex allowed to obtain enantiomerically enriched α-fluoro-β-ketoesters in high yields and moderate enantioselectivities; up to 67% ee. A comparison with previously reported chiral ligands is provided.     

One-step Oxidative Monofluorination of Electron-Deficient Sulfoxides to Access Highly Lewis Acidic Sulfur(VI) Cations

The strongly oxidizing, powerful electrophilic fluorination reagent [FXe][OTf] is shown to effect direct oxidative monofluorination of sulfoxides. This one-step, chloride promoter-free methodology provides access to so far inaccessible, yet highly desirable strongly Lewis acidic fluorosulfoxonium cations from electron-deficient and/or sterically demanding sulfoxides that are shown to be practically unreactive towards the previously reported XeF₂/NEt₄Cl system. Experimental and density functional theory studies have been conducted to assess the Lewis acidities of the prepared sulfur(VI) cations. Preliminary results obtained with chiral sulfoxides provide early insights into the mechanism of these fluorination reactions.     

Reaction of Nitrosonium （NO^＋） with Schiff Bases

The reaction of nitrosonium (NO^ ) with Schiff bases produced diazonium salts and aldehydes in good yield. The reaction is assumed to be an electrophilic reaction of nitrosonium with imines via a four-member ring intermediate.     

Phenyltetrafluorotelluromethoxide — a new fluorinating reagent for olefins

Phenyltetrafluorotelluromethoxide fluorinates olefins to form 1,2-difluorides. The reaction with styrene afforded 1-fluoro-4-phenyl-1,2-dihydronaphthalene as the main product. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 742–744, April, 1998     

Selective direct fluorination of quinoline derivatives

Direct fluorination of various quinoline derivatives in acidic reaction media gives fluorinated quinoline products arising from selective, efficient electrophilic substitution processes.