17554-55-1Relevant academic research and scientific papers
Site-Specific Oxidation of (sp3)C-C(sp3)/H Bonds by NaNO2/HCl
Zhao, Jianyou,Shen, Tong,Sun, Zhihui,Wang, Nengyong,Yang, Le,Wu, Jintao,You, Huichao,Liu, Zhong-Quan
supporting information, p. 4057 - 4061 (2021/05/26)
A site-specific oxidation of (sp3)C-C(sp3) and (sp3)C-H bonds in aryl alkanes by the use of NaNO2/HCl was explored. The method is chemical-oxidant-free, transition-metal-free, uses water as the solvent, and proceeds under mild conditions, making it valuable and attractive to synthetic organic chemistry.
Trialkylammonium salt degradation: Implications for methylation and cross-coupling
Assante, Michele,Baillie, Sharon E.,Juba, Vanessa,Leach, Andrew G.,McKinney, David,Reid, Marc,Washington, Jack B.,Yan, Chunhui
, p. 6949 - 6963 (2021/06/02)
Trialkylammonium (most notably N,N,N-trimethylanilinium) salts are known to display dual reactivity through both the aryl group and the N-methyl groups. These salts have thus been widely applied in cross-coupling, aryl etherification, fluorine radiolabelling, phase-transfer catalysis, supramolecular recognition, polymer design, and (more recently) methylation. However, their application as electrophilic methylating reagents remains somewhat underexplored, and an understanding of their arylation versus methylation reactivities is lacking. This study presents a mechanistic degradation analysis of N,N,N-trimethylanilinium salts and highlights the implications for synthetic applications of this important class of salts. Kinetic degradation studies, in both solid and solution phases, have delivered insights into the physical and chemical parameters affecting anilinium salt stability. 1H NMR kinetic analysis of salt degradation has evidenced thermal degradation to methyl iodide and the parent aniline, consistent with a closed-shell SN2-centred degradative pathway, and methyl iodide being the key reactive species in applied methylation procedures. Furthermore, the effect of halide and non-nucleophilic counterions on salt degradation has been investigated, along with deuterium isotope and solvent effects. New mechanistic insights have enabled the investigation of the use of trimethylanilinium salts in O-methylation and in improved cross-coupling strategies. Finally, detailed computational studies have helped highlight limitations in the current state-of-the-art of solvation modelling of reaction in which the bulk medium undergoes experimentally observable changes over the reaction timecourse. This journal is
Copper catalyzed Heck-like cyclizations of oxime esters
Faulkner, Adele,Race, Nicholas J.,Scott, James S.,Bower, John F.
, p. 2416 - 2421 (2014/05/20)
Copper catalyzed Heck-like cyclizations of oxime esters are described. Mechanistic studies indicate a reaction pathway that proceeds via the generation and cyclization of an intermediate that possesses iminyl radical character. To the best of our knowledge, this work encompasses the first examples of Cu-catalyzed aza-Heck reactions that proceed via oxidative initiation at nitrogen to generate products containing a new alkene. This new protocol is also an effective alternative to Pd-based systems and highlights the value of replacing precious metal catalysts with cheaper and more sustainable variants. This journal is the Partner Organisations 2014.
Formal total synthesis of (±)-estrone and zirconocene-promoted cyclization of 2-fluoro-1,7-octadienes and ru-catalyzed ring closing metathesis
Herrmann, Pavel,Budesinsky, Milos,Kotora, Martin
, p. 6202 - 6206 (2008/12/22)
(Chemical Equation Presented) A new and diastereoselective method for the synthesis of the estrone skeleton from a substituted styrene based on sequential 3-fold use of Cp2ZrBu2 (oxidative addition-alkylation and two cyclization-alkylation sequences) and a ruthenium complex catalyzed RC-metathesis of a sterically hindered diene was developed. The prepared estratetraene was obtained in 7 steps from a commercially available starting material and thus the overall synthesis of estrone could be accomplished in 9 steps. Moreover, we have also found that the course of the reaction of substrates bearing the 2-halo-1,7-diene moiety with Cp2ZrBu 2, i.e., cyclization or oxidative addition to the C-X bond, could be controlled by the nature of the halogen leaving group.
HELIX 12 DIRECTED STEROIDAL PHARMACEUTICAL PRODUCTS
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Page/Page column 62-63, (2010/02/12)
Compounds having the structure or their salts: are used to treat or reduce le likelihood of acquiring androgen-dependent diseases, such as prostate cancer, benign prostatic hyperplasia, polycystic ovarian syndrome, acne, hirsutism, seborrhea, androgenic alopecia and male baldness. They can be formulated together with pharmaceutically acceptable diluent or carrier or otherwise made into any pharmaceutical dosage form. Some of these compounds having tissue-specific antiandrogenic activity and tissue-specific androgenic activity can be used to treat or reduce the risk of developing diseases related to loss of androgenic stimulation. Combinations with other active pharmaceutical agents are also disclosed.
Total synthesis with a chirogenic opening move demonstrated on steroids with estrane or 18a-homoestrane skeleton
Quinkert,Del Grosso,Doring,Doring,Schenkel,Bauch,Dambacher,Bats,Zimmermann,Durner
, p. 1345 - 1391 (2007/10/02)
A concept of first choice for the synthesis of the title compounds had been proposed by Dane in the late 1930s. It was soon turned down, because the opening move - a chirogenic Diels-Alder reaction - did not work. With Lewis acids as mediators, however, a successful start has been achieved now. With Ti complexes of chelating ligands (Seebach's TADDOLs (= α,α,α',α'-tetraaryl-1,3-dioxolane-4,5-dimethanols)), enantioselective formation of the desired adducts does occur. Efficient total syntheses of 2 and 3a have been accomplished.
QUINALDYL ETHERS AS LATENT CARBONYL FUNCTIONS
Rukachaisirikul, Vatcharin,Koert, Ulrich,Hoffmann, Reinhard W.
, p. 4533 - 4544 (2007/10/02)
Ketones can be generated from secondary alcohols by converting the latter into quinaldine ethers followed by irradiation (>320 nm).The quinaldine ethers can therefore be utilized as latent carbonyl groups.The quinaldine group is chemically inert during transformations at other parts of the molecule involving hydroboration, Grignard reagents, LiAlH4, as well as bromine or ozone. Key Words: Ketone formation, photochemical; Protecting group
Anionic Fries Rearrangements of Esters of ortho-Iodobenzyl Alcohols: Rapid Routes to Oestrone Methyl Ether and Its 9β Epimer, and Aryl Naphthalide Lignans
Horne, Stephen,Rodrigo, Russell
, p. 164 - 166 (2007/10/02)
A fast, general, low-temperature rearrangement of ortho-iodobenzyl esters, triggered by lithium-iodine exchange, leads to isobenzofurans which are intercepted in situ by inter and intramolecular Diels-Alder (IMDA) reactions to produce a variety of carbocycles including natural lignans and steroids.
EFFICIENT APPROACH TO THE OPPOLZER-KAMETANI INTERMEDIATE FOR ESTRONE METHYL ETHER USING THE CONJUGATE ADDITION-ENOLATE METHYLATION OF THE CYCLOPENTENONE CONTAINING AN α-APPENDED BENZOCYCLOBUTANE MOIETY
Takahashi, Takashi,Shimizu, Katsuya,Doi, Takayuki,Tsuji, Jiro,Yamamoto, Keiji
, p. 4999 - 5002 (2007/10/02)
Simple synthesis of (+/-)-estrone methyl ether by the conjugate addition-enolate methylation of the 2-alkylcyclopentenone followed by the intramolecular Diels-Alder reaction of the o-quinodimethane, and discussions for the diastereoselectivity in the enolate-methylation based on the MM2 transition structure model are presented.
Dimethylcarbonat als Methylierungsmittel unter phasen-transfer-katalytischen Bedingungen
Lissel, Manfred,Schmidt, Stefan,Neumann, Beate
, p. 382 - 383 (2007/10/02)
Dimethyl carbonate (as well as diethyl, diallyl, dibenzyl carbonate and ethane-1,2-diyl carbonate) in the presence of potassium carbonate and 18-crown-6 (or Aliqual 336) is a versatile, cheap, and safer reagent for the methylation of a variety of organic substrates.
