- One-Pot Deoxygenation and Substitution of Alcohols Mediated by Sulfuryl Fluoride
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Sulfuryl fluoride is a valuable reagent for the one-pot activation and derivatization of aliphatic alcohols, but the highly reactive alkyl fluorosulfate intermediates limit both the types of reactions that can be accessed as well as the scope. Herein, we report the SO2F2-mediated alcohol substitution and deoxygenation method that relies on the conversion of fluorosulfates to alkyl halide intermediates. This strategy allows the expansion of SO2F2-mediated one-pot processes to include radical reactions, where the alkyl halides can also be exploited in the one-pot deoxygenation of primary alcohols under mild conditions (52-95% yield). This strategy can also enhance the scope of substitutions to nucleophiles that are previously incompatible with one-pot SO2F2-mediated alcohol activation and enables substitution of primary and secondary alcohols in 54-95% yield. Chiral secondary alcohols undergo a highly stereospecific (90-98% ee) double nucleophilic displacement with an overall retention of configuration.
- Epifanov, Maxim,Mo, Jia Yi,Dubois, Rudy,Yu, Hao,Sammis, Glenn M.
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p. 3768 - 3777
(2021/03/01)
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- Conversion of Aryl Aldehydes to Benzyl Iodides and Diarylmethanes by H3PO3/I2
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For the first time, H3PO3 was used as both the reducing reagent and the promotor in the reductive benzylation reactions with aryl aldehydes. By using a H3PO3/I2 combination, various aromatic aldehydes underwent iodination reactions and Friedel-Crafts type reactions with arenes via benzyl iodide intermediates, readily producing benzyl iodides and diarylmethanes in good yields. Intramolecular cyclization reactions also took place, giving the corresponding cyclic compounds. This new strategy features easy-handling, low-cost, and metal-free conditions.
- Lv, Fang,Xiao, Jing,Xiang, Junchun,Guo, Fengzhe,Tang, Zi-Long,Han, Li-Biao
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p. 3081 - 3088
(2021/02/01)
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- Preparation method of benzyl iodide and derivatives thereof
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The invention discloses a preparation method of benzyl iodide and derivatives thereof, which comprises the following steps: in a protective atmosphere, carrying out heating reaction on aryl aldehyde and iodine elementary substance in the presence of a solvent and phosphorous acid to obtain benzyl iodide and derivatives thereof. According to the method, cheap and green solid phosphorous acid is selected as a reduction reagent for reaction, elemental iodine is selected as an iodine source, the benzyl iodide and the derivatives thereof are efficiently prepared from the aryl aldehyde compounds which are simple and easy to obtain by a one-pot one-step method under mild conditions, and the method has the advantages of simplicity in operation, cheap and easily available reagents, environmental friendliness and the like; and the use of expensive silicon-hydrogen compounds and transition metal catalysts is avoided, and the yield can reach 94% at most, so that the method is beneficial to industrial production.
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Paragraph 0069-0072
(2021/05/01)
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- Taming Ambident Triazole Anions: Regioselective Ion Pairing Catalyzes Direct N-Alkylation with Atypical Regioselectivity
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Controlling the regioselectivity of ambident nucleophiles toward alkylating agents is a fundamental problem in heterocyclic chemistry. Unsubstituted triazoles are particularly challenging, often requiring inefficient stepwise protection-deprotection strategies and prefunctionalization protocols. Herein we report on the alkylation of archetypal ambident 1,2,4-triazole, 1,2,3-triazole, and their anions, analyzed by in situ 1H/19F NMR, kinetic modeling, diffusion-ordered NMR spectroscopy, X-ray crystallography, highly correlated coupled-cluster computations [CCSD(T)-F12, DF-LCCSD(T)-F12, DLPNO-CCSD(T)], and Marcus theory. The resulting mechanistic insights allow design of an organocatalytic methodology for ambident control in the direct N-alkylation of unsubstituted triazole anions. Amidinium and guanidinium receptors are shown to act as strongly coordinating phase-transfer organocatalysts, shuttling triazolate anions into solution. The intimate ion pairs formed in solution retain the reactivity of liberated triazole anions but, by virtue of highly regioselective ion pairing, exhibit alkylation selectivities that are completely inverted (1,2,4-triazole) or substantially enhanced (1,2,3-triazole) compared to the parent anions. The methodology allows direct access to 4-alkyl-1,2,4-triazoles (rr up to 94:6) and 1-alkyl-1,2,3-triazoles (rr up to 99:1) in one step. Regioselective ion pairing acts in effect as a noncovalent in situ protection mechanism, a concept that may have broader application in the control of ambident systems.
- Dale, Harvey J.A.,Hodges, George R.,Lloyd-Jones, Guy C.
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supporting information
p. 7181 - 7193
(2019/05/10)
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- Rhodium-Catalyzed Generation of Anhydrous Hydrogen Iodide: An Effective Method for the Preparation of Iodoalkanes
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The preparation of anhydrous hydrogen iodide directly from molecular hydrogen and iodine using a rhodium catalyst is reported for the first time. The anhydrous hydrogen iodide generated was proven to be highly active in the transformations of alkenes, phenyl aldehydes, alcohols, and cyclic ethers to the corresponding iodoalkanes. Therefore, the present methodology not only has provided convenient access to anhydrous hydrogen iodide but also offers a practical preparation method for various iodoalkanes in excellent atom economy.
- Zeng, Chaoyuan,Shen, Guoli,Yang, Fan,Chen, Jingchao,Zhang, Xuexin,Gu, Cuiping,Zhou, Yongyun,Fan, Baomin
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supporting information
p. 6859 - 6862
(2018/10/25)
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- N-Hydroxyphthalimide-Mediated Electrochemical Iodination of Methylarenes and Comparison to Electron-Transfer-Initiated C-H Functionalization
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An electrochemical method has been developed for selective benzylic iodination of methylarenes. The reactions feature the first use of N-hydroxyphthalimide as an electrochemical mediator for C-H oxidation to nonoxygenated products. The method provides the basis for direct (in situ) or sequential benzylation of diverse nucleophiles using methylarenes as the alkylating agent. The hydrogen-atom transfer mechanism for C-H iodination allows C-H oxidation to proceed with minimal dependence on the substrate electronic properties and at electrode potentials 0.5-1.2 V lower than that of direct electrochemical C-H oxidation.
- Rafiee, Mohammad,Wang, Fei,Hruszkewycz, Damian P.,Stahl, Shannon S.
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supporting information
p. 22 - 25
(2018/01/17)
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- Catalytic Halogen Bond Activation in the Benzylic C-H Bond Iodination with Iodohydantoins
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This letter presents the side-chain iodination of electron-deficient benzylic hydrocarbons at rt using N-hydroxyphthalimide (NHPI) as radical initiator and 1,3-diiodo-5,5-dimethylhydantoin and 3-iodo-1,5,5-trimethylhydantoin (3-ITMH) as iodine source. Addition of a carboxylic acid increased the reactivity due to complex formation with and activation of 3-ITMH by proton transfer and halogen bond formation. No SEAr reactions were observed under the employed reaction conditions. Our method enables convenient product isolation and gives 50-72% yields of isolated products.
- Combe, Sascha H.,Hosseini, Abolfazl,Song, Lijuan,Hausmann, Heike,Schreiner, Peter R.
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supporting information
p. 6156 - 6159
(2017/11/24)
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- Aliphatic C-H Bond Iodination by a N-Iodoamide and Isolation of an Elusive N-Amidyl Radical
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Contrary to C-H chlorination and bromination, the direct iodination of alkanes represents a great challenge. We reveal a new N-iodoamide that is capable of a direct and efficient C-H bond iodination of various cyclic and acyclic alkanes providing iodoalkanes in good yields. This is the first use of N-iodoamide for C-H bond iodination. The method also works well for benzylic C-H bonds, thereby constituting the missing version of the Wohl-Ziegler iodination reaction. Mechanistic details were elucidated by DFT computations, and the N-centered radical derived from the used N-iodoamide, which is the key intermediate in this process, was matrix-isolated in a solid argon matrix and characterized by UV-vis as well as IR spectroscopy.
- Artaryan, Alexander,Mardyukov, Artur,Kulbitski, Kseniya,Avigdori, Idan,Nisnevich, Gennady A.,Schreiner, Peter R.,Gandelman, Mark
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p. 7093 - 7100
(2017/07/26)
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- PROCESS FOR THE PREPARATION OF N-IODOAMIDES
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The present invention provides new stable crystalline N-iodoamides - 1-iodo- 3,5,5-trimethylhydantoin (1-ITMH) and 3-iodo-4,4-dimethyl-2-oxazolidinone (IDMO). The present invention further provides a process for the preparation of organic iodides using N-iodoamides of this invention and recovery of the amide co-products from waste water.
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Paragraph 00282-00283
(2015/05/26)
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- Design, synthesis and anticancer activities of novel otobain derivatives
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A series of novel racemic otobain derivatives was designed and synthesised using 2-piperonyl-1,3-dithianes in the conjugate addition-alkylation to 5H-furan-2-one, followed by cationic cyclisation. All the synthesised compounds were consequently evaluated for their anticancer activity against several human cancers in vitro. The efficacy of the most active compound 27g was comparable with etoposide, with IC50 values ranging from 1.06 μM to 4.16 μM in different cancer cell lines. Notably, compound 27g strongly induced cell cycle arrest and increased the expression of mitosis-specific markers MPM-2 and phosphorylated histone H3, but it did not trigger cell apoptosis. Further a colony formation assay showed that compound 27g effectively inhibited the anchor growth of lung cancer cells in a dose-dependent manner. More importantly, compound 27g at 40 mg kg-1 significantly suppressed tumour volume (P 0.01) and tumour weight (P 0.05) in a human lung cancer cell xenograft mouse model without causing systematic toxicity in mice. Our findings indicated that compound 27g has significant potential for further drug development.
- Li, Zhongzhou,Su, Hui,Yu, Weiwei,Li, Xinjun,Cheng, Hao,Liu, Mingyao,Pang, Xiufeng,Zou, Xinzhuo
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p. 277 - 287
(2015/12/30)
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- Palladium-mediated carboxylation of aryl halides (triflates) or benzyl halides using [13C]/[11C]carbon monoxide with tetrabutylammonium hydroxide or trimethylphenylammonium hydroxide
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[Carbonyl-11C]carboxylic acids were synthesised using palladium-mediated reaction of [11C]carbon monoxide with aryl halides/triflates and benzyl halides in combination with either tetrabutylammonium hydroxide or trimethylphenylammoni
- Karimi, Farhad,Langstroem, Bengt
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p. 2256 - 2259
(2007/10/03)
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- Selective iodination of benzylic alcohols with KI/H2SO4 supported on natural kaolinitic clay under microwave irradiation
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Benzylic alcohols are selectively converted into their corresponding iodides using KI/H2SO4 supported on natural kaolinitic clay and microwaves.
- Bandgar, Babasaheb P.,Sadavarte, Vibhav S.,Bettigeri, Sampada V.
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p. 345 - 348
(2007/10/03)
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- A general, convenient and highly efficient synthesis of diarylmethanes by copper-catalyzed reaction
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Copper-catalyzed reactions of arylmagnesium derivatives with benzyliodides have been developed for the large scale preparation of diarylmethanes. Various diarylmethanes have been prepared in high yield by this reaction, the amount of homocoupled dimers be
- Ku, Yi-Yin,Patel, Ramesh R.,Sawick, David P.
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p. 1949 - 1952
(2007/10/03)
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- Benzylation via Tandem Grignard Reaction - Iodotrimethylsilane (TMSI) Mediated Reduction
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A method has been developed which allows for the large scale preparation of biarylmethanes.This method involves the initial formation of biarylmethanols via reaction of aryl Grignards with carbonyl compounds followed by a subsequent reduction with iodotrimethylsilane (TMSI).A number of improvements over existing literature procedures are reported as well as previously unobserved dimerizations.Studies reveal that as few as 3 equiv of TMSI will give complete reduction in most cases where either of the substituents are not heteroaromatic.Mono-substituted alkanols react with TMSI to afford the corresponding iodides.A mechanistic study of the TMSI reduction is also reported.
- Stoner, Eric J.,Cothron, Darlene A.,Balmer, Mary K.,Roden, Brian A.
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p. 11043 - 11062
(2007/10/02)
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- Antitumor agents. 120. New 4-substituted benzylamine and benzyl ether derivatives of 4'-O-demethylepipodophyollotoxin as potent inhibitors of human DNA topoisomerase II
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A number of new 4'-O-demethylepipodophyllotoxin derivatives possessing various 4β-N- or 4β-O-benzyl groups have been synthesized and evaluated for their inhibitory activity against the human DNA topoisomerase II as well as for their activity in causing cellular protein-linked DNA breakage. The 4β-N-benzyl derivatives 9-22 are, in general, as active or more active than etoposide (1). The most active compounds are 14, 16, and 17, which are more than 2-fold more potent than 1. The results indicated that a basic unsubstituted 4β-benzylamino moiety is structurally required for the enhanced activity. Replacement of the benzyl nitrogen with oxygen gave compounds (23 and 24) which are inactive. The ability of these compounds to inhibit human DNA topoisomerase II and to cause protein-linked DNA breakage appears to have no direct correlation with cytotoxicity in KB cells.
- Zhou,Wang,Chang,Chen,Cheng,Lee
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p. 3346 - 3350
(2007/10/02)
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