910-31-6Relevant articles and documents
Regioselective opening of a cyclopropane ring by mercury(II) and transmetalation of the product with molybdenum. A novel, stereoelectronically controlled, skeletal rearrangement ans Grob-type fragmentation of organomolybdenum intermediates
Srogl, Jiri,Kocovsky, Pavel
, p. 5991 - 5994 (1992)
Organomercurial 2, arising by a regioselective ring-opening of cyclopropane derivative 1, can be transmetalated with Mo-reagents to initially generate complexes 3 and 7. While 3 reacts further via a stereoelectronically controlled cascade rearrangement to afford 6, complex 7 favors a Grob-type fragmentation leading to 9.
Novel synthesis of 5-hydroxy-5α-cholesta-2,7-dien-6-one and its criegee hydroxylation
Kovganko,Sokolov
, p. 590 - 594 (2000)
Cholesterol (1) is used to synthesize again 5α-hydroxy-2,7-dien-6-one (5) through the intermediates 2-4. cis-Hydroxylation of 5 with OsO4 and subsequent acetylation give steroids 6-8. Dehydration of 5α-hydroxy-6-ketone 6 forms the unsaturated compounds 9-11.
A mild method for the replacement of a hydroxyl group by halogen: 2. unified procedure and stereochemical studies
Gati, Wafa,Munyemana, Fran?ois,Colens, Alain,Srour, Aladdin,Dufour, Mathilde,Vardhan Reddy, K. Harsha,Téchy, Brigitte,Rosse, Gérard,Schweiger, Ed,Qiao, Qi,Ghosez, Léon
, (2020/08/19)
N,N-Dimethyl- and N,N-diisopropyl-1-halo-2-methyl-l-propenylamines are readily available reagents for the mild deoxyhalogenation of alcohols and hydroxyacids. In this study we showed that the reactivity of the reagents can be tuned by varying the size of the alkyl groups on the reagents: the replacement of methyl by isopropyl groups led to a significant increase of reactivity. We then described a unified procedure for all deoxyhalogenations using the readily available α-chloroenamines as reagents with (bromination, iodination) or without (chlorination) an alkaline bromide or iodide. Finally, we showed that deoxyhalogenation reactions of secondary alcohols were highly stereospecific and generally occurred with inversion of configuration.
A General Catalytic Method for Highly Cost- and Atom-Efficient Nucleophilic Substitutions
Huy, Peter H.,Filbrich, Isabel
supporting information, p. 7410 - 7416 (2018/04/30)
A general formamide-catalyzed protocol for the efficient transformation of alcohols into alkyl chlorides, which is promoted by substoichiometric amounts (down to 34 mol %) of inexpensive trichlorotriazine (TCT), is introduced. This is the first example of a TCT-mediated dihydroxychlorination of an OH-containing substrate (e.g., alcohols and carboxylic acids) in which all three chlorine atoms of TCT are transferred to the starting material. The consequently enhanced atom economy facilitates a significantly improved waste balance (E-factors down to 4), cost efficiency, and scalability (>50 g). Furthermore, the current procedure is distinguished by high levels of functional-group compatibility and stereoselectivity, as only weakly acidic cyanuric acid is released as exclusive byproduct. Finally, a one-pot protocol for the preparation of amines, azides, ethers, and sulfides enabled the synthesis of the drug rivastigmine with twofold SN2 inversion, which demonstrates the high practical value of the presented method.
Ti-Catalyzed Radical Alkylation of Secondary and Tertiary Alkyl Chlorides Using Michael Acceptors
Wu, Xiangyu,Hao, Wei,Ye, Ke-Yin,Jiang, Binyang,Pombar, Gisselle,Song, Zhidong,Lin, Song
, p. 14836 - 14843 (2018/11/10)
Alkyl chlorides are common functional groups in synthetic organic chemistry. However, the engagement of unactivated alkyl chlorides, especially tertiary alkyl chlorides, in transition-metal-catalyzed C-C bond formation remains challenging. Herein, we describe the development of a TiIII-catalyzed radical addition of 2° and 3° alkyl chlorides to electron-deficient alkenes. Mechanistic data are consistent with inner-sphere activation of the C-Cl bond featuring TiIII-mediated Cl atom abstraction. Evidence suggests that the active TiIII catalyst is generated from the TiIV precursor in a Lewis-acid-assisted electron transfer process.
Dehalogenation of vicinal dihalo compounds by 1,1′-bis(trimethylsilyl)-1: H,1′ H-4,4′-bipyridinylidene for giving alkenes and alkynes in a salt-free manner
Rej, Supriya,Pramanik, Suman,Tsurugi, Hayato,Mashima, Kazushi
supporting information, p. 13157 - 13160 (2017/12/26)
We report a transition metal-free dehalogenation of vicinal dihalo compounds by 1,1′-bis(trimethylsilyl)-1H,1′H-4,4′-bipyridinylidene (1) under mild conditions, in which trimethylsilyl halide and 4,4′-bipyridine were generated as byproducts. The synthetic protocol for this dehalogenation reaction was effective for a wide scope of dibromo compounds as substrates while keeping the various functional groups intact. Furthermore, the reduction of vicinal dichloro alkanes and vicinal dibromo alkenes also proceeded in a salt-free manner to afford the corresponding alkenes and alkynes.
METHOD OF CONVERTING ALCOHOL TO HALIDE
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Page/Page column 51; 181, (2017/01/02)
The present invention relates to a method of converting an alcohol into a corresponding halide. This method comprises reacting the alcohol with an optionally substituted aromatic carboxylic acid halide in presence of an N-substituted formamide to replace a hydroxyl group of the alcohol by a halogen atom. The present invention also relates to a method of converting an alcohol into a corresponding substitution product. The second method comprises: (a) performing the method of the invention of converting an alcohol into the corresponding halide; and (b) reacting the corresponding halide with a nucleophile to convert the halide into the nucleophilic substitution product.
Formamides as Lewis Base Catalysts in SNReactions—Efficient Transformation of Alcohols into Chlorides, Amines, and Ethers
Huy, Peter H.,Motsch, Sebastian,Kappler, Sarah M.
supporting information, p. 10145 - 10149 (2016/08/16)
A simple formamide catalyst facilitates the efficient transformation of alcohols into alkyl chlorides with benzoyl chloride as the sole reagent. These nucleophilic substitutions proceed through iminium-activated alcohols as intermediates. The novel method, which can be even performed under solvent-free conditions, is distinguished by an excellent functional group tolerance, scalability (>100 g) and waste-balance (E-factor down to 2). Chiral substrates are converted with excellent levels of stereochemical inversion (99 %→≥95 % ee). In a practical one-pot procedure, the primary formed chlorides can be further transformed into amines, azides, ethers, sulfides, and nitriles. The value of the method was demonstrated in straightforward syntheses of the drugs rac-Clopidogrel and S-Fendiline.
Hantzsch Ester as a Photosensitizer for the Visible-Light-Induced Debromination of Vicinal Dibromo Compounds
Chen, Wenxin,Tao, Huachen,Huang, Wenhao,Wang, Guoqiang,Li, Shuhua,Cheng, Xu,Li, Guigen
supporting information, p. 9546 - 9550 (2016/07/14)
The debromination of vicinal dibromo compounds to generate alkenes usually requires harsh reaction conditions and the addition of catalysts. Just recently the visible-light-induced debromination of vicinal dibromo compounds emerged as a possible alternative to commonly used methods, but the substrate scope of this reaction is limited and a photocatalyst is necessary for the successful conversion of the starting compounds. A catalyst-free visible-light-induced debromination of vicinal dibromo compounds with a base-activated Hantzsch ester as photosensitizer is reported. The method has a wide substrate scope and a broad functional-group compatibility.
Synthesis and characterization of steroidal heterocyclic compounds, DNA condensation and molecular docking studies and their in vitro anticancer and acetylcholinesterase inhibition activities
Ali, Abad,Asif, Mohd,Khanam, Hena,Mashrai, Ashraf,Sherwani, Mohd Asif,Owais, Mohammad,Shamsuzzaman
, p. 75964 - 75984 (2015/09/28)
A facile, convenient and efficient approach for the synthesis of a new series of steroidal heterocyclic compounds (4-12) by reacting a mixture of compounds (1e-3e) with o-aminothiophenol/o-aminophenol/o-phenylenediamine is reported. The structural assignment of products is confirmed on the basis of IR, 1H NMR, 13C NMR, MS and analytical data. The compounds obey the Lipinski's 'Rule of Five' analysis based on computational prediction and pharmacokinetic properties. The anticancer activity has been tested in vitro against three cancer cell lines Hep3B (human hepatocellular carcinoma), MCF7 (human breast adenocarcinoma), HeLa (human cervical carcinoma) and one non-cancer normal cell i.e. PBMCs (peripheral blood mononuclear cell) by MTT assay. In addition, the synthesized compounds are also tested for their in vitro antioxidant activity by various reported methods in which compounds 10-12 exhibited good antioxidant activity. Nonenzymatic degradation of DNA has been investigated. The acetylcholinesterase (AChE) inhibitor activities of the steroidal derivatives are also evaluated using Ellman's method. Moreover, the application of compound 6 as a DNA gene transporter is evaluated by DNA condensation and ascertained by employing TEM and AFM, which illustrate that the compound 6 induces the condensation of CT-DNA. Molecular docking studies further characterize the interaction of the synthesized compounds with DNA. 2015
