- Pseudocyclic bis-N-heterocycle-stabilized iodanes - synthesis, characterization and applications
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Bis-N-heterocycle-stabilized λ3-iodanes (BNHIs) based on azoles are introduced as novel structural motifs in hypervalent iodine chemistry. A performance test in a variety of benchmark reactions including sulfoxidations and phenol dearomatizations revealed a bis-N-bound pyrazole substituted BNHI as the most reactive derivative. Its solid-state structure was characterizedviaX-ray analysis implying strong intramolecular interactions between the pyrazole nitrogen atoms and the hypervalent iodine centre.
- Boelke, Andreas,Lork, Enno,Nachtsheim, Boris J.,Sadat, Soleicha
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supporting information
p. 7434 - 7437
(2021/08/03)
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- Rapid Iododeboronation with and without Gold Catalysis: Application to Radiolabelling of Arenes
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Radiopharmaceuticals that incorporate radioactive iodine in combination with single-photon emission computed tomography imaging play a key role in nuclear medicine, with applications in drug development and disease diagnosis. Despite this importance, there are relatively few general methods for the incorporation of radioiodine into small molecules. This work reports a rapid air- and moisture-stable ipso-iododeboronation procedure that uses NIS in the non-toxic, green solvent dimethyl carbonate. The fast reaction and mild conditions of the gold-catalysed method led to the development of a highly efficient process for the radiolabelling of arenes, which constitutes the first example of an application of homogenous gold catalysis to selective radiosynthesis. This was exemplified by the efficient synthesis of radiolabelled meta-[125I]iodobenzylguanidine, a radiopharmaceutical that is used for the imaging and therapy of human norepinephrine transporter-expressing tumours.
- Webster, Stacey,O'Rourke, Kerry M.,Fletcher, Conor,Pimlott, Sally L.,Sutherland, Andrew,Lee, Ai-Lan
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supporting information
p. 937 - 943
(2017/12/26)
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- Room-Temperature Gold-Catalysed Arylation of Heteroarenes: Complementarity to Palladium Catalysis
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Tailoring of the pre-catalyst, the oxidant and the arylsilane enables the first room-temperature, gold-catalysed, innate C?H arylation of heteroarenes. Regioselectivity is consistently high and, in some cases, distinct from that reported with palladium ca
- Cresswell, Alexander J.,Lloyd-Jones, Guy C.
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supporting information
p. 12641 - 12645
(2016/08/30)
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- Cu(II)-catalyzed direct and site-selective arylation of indoles under mild conditions
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We have developed a new site-selective Cu(II)-catalyzed C-H bond functionalization process that can selectively arylate indoles at either the C3 or C2 position under mild conditions. The scope of the arylation process is broad and tolerates broad functionality on both the indole and aryl unit, which makes it amenable to further elaboration. The mechanism of the arylation reaction is proposed to proceed via a Cu(III)-aryl species that undergoes initial electrophilic addition at the C3 position of the indole motif. We speculate that site of indole arylation arises through a migration of the Cu(III)-aryl group from C3 to C2, and this can be controlled by the nature of the group on the nitrogen atom; free (NH)- and N-alkylindoles deliver the C3-arylated product, whereas N-acetylindoles afford the C2 isomer, both with excellent yield and selectivity. Copyright
- Phipps, Robert J.,Grimster, Neil P.,Gaunt, Matthew J.
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supporting information; experimental part
p. 8172 - 8174
(2009/02/02)
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- Progressive direct iodination of sterically hindered alkyl substituted benzenes
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Benzene derivatives bearing at least one bulky alkyl group (i-Pr or t-Bu) were selectively and effectively iodinated using elemental iodine activated, by 1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (Selectfluor, F-TED
- Stavber, Stojan,Kralj, Petra,Zupan, Marko
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p. 1513 - 1518
(2007/10/03)
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- Reactions of diaryliodonium trifluoromethanesulfonates with low-valent ytterbium and samarium reagents
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The reduction of diaryliodonium trifluoromethanesulfonates with low-valent ytterbium and samarium reagents has been studied. In the reaction of diphenyliodonium trifluoromethanesulfonate with two equimolar amounts of metallic ytterbium, benzene is formed
- Makioka, Yoshikazu,Fujiwara, Yuzo,Kitamura, Tsugio
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p. 509 - 513
(2007/10/03)
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- Synthetic use of poly[4-(diacetoxyiodo)styrene] for organic reactions
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Poly[4-(diacetoxyiodo)styrene] is sufficiently reactive for the iodination of aromatics, the oxidative 1,2-aryl migration of alkyl aryl ketones, the α-hydroxylation of ketones, and the oxidation of hydroquinones and sulfides similarly to (diacetoxyiodo)benzene. Here, those reactions with poly[4-(diacetoxyiodo)styrene] are very useful because of the simple operation; thus, filtration gives the crude products and recovered poly(4- iodostyrene), and then poly[4-(diacetoxyiodo)-styrene] can be regenerated by oxidation of the recovered poly(4-iodostyrene), which are reused for the same reactions.
- Togo, Hideo,Abe, Seiichiro,Nogami, Genki,Yokohama, Masataka
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p. 2351 - 2356
(2007/10/03)
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- Reactivity and synthetic utility of 1-(arenesulfonyloxy) benziodoxolones
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The reactivity and synthetic use of 1-(arenesulfonyloxy)benziodoxolones were studied. In the presence of iodine, 1-(arenesulfonyloxy)benziodoxolones iodinated various aromatics to give iodoarenes in moderate to good yields. In particular, 1-(p-chlorobenzenesulfonyloxy)benziodoxolone showed the best reactivity. Using a halide salt such as lithium bromide or lithium chloride instead of iodine, the corresponding aryl bromides and chlorides were also obtained in good yields. In the absence of aromatics, 1- (arenesulfonyloxy)benziodoxolones gave rise to desulfonyloxyiodination reactions to give the corresponding aryl iodides via electrophilic ipso substitution on the aromatic rings. Furthermore, the l-(p- toluenesulfonyloxy)benziodoxolone/iodine system iodotosyloxylated alkynes in good yields. These reactions proceeded via the formation of arenesulfonyl hypoiodites.
- Muraki, Takahito,Togo, Hideo,Yokoyama, Masataka
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p. 2883 - 2889
(2007/10/03)
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- Synthetic application of poly[styrene(iodoso diacetate)]
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Poly[styrene(iodoso diacetate)] is sufficiently reactive to effect the iodination of aromatics and oxidative 1,2-aryl migration of alkyl aryl ketones as (diacetoxyiodo)benzene, and can be regenerated and reused for the same reactions.
- Togo, Hideo,Nogami, Genki,Yokoyama, Masataka
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p. 534 - 536
(2007/10/03)
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- Synthetic use of 1-(p-toluenesulfonyloxy)-1,2-benziodoxol-3(1H)-one: Iodination of aromatic rings
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Treatment of various aromatic compounds with 1-(p-toluenesulfonyloxy)-1,2-benziodoxol-3(1H)-one 1A and iodine gave the corresponding iodinated compounds in good yields. Similarly, chlorination and bromination proceeded effectively. As compared with other trivalent iodine compounds, the iodinane 1A showed the best reactivity as a halogenation reagent.
- Muraki, Takahito,Togo, Hideo,Yokoyama, Masataka
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p. 286 - 288
(2007/10/03)
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