30314-44-4Relevant academic research and scientific papers
Synthesis of 1,2,4-Trithiolanes from Thione S-Oxides and Lawesson Reagent at Room Temperature
Okuma, Kentaro,Shigetomi, Toshiyuki,Shibata, Shinji,Shioji, Kosei
, p. 187 - 188 (2004)
The reaction of 2,2,4,4-tetramethyl-3-thioxocyclobutanone S-oxide with Lawesson reagent (L. R.) afforded the corresponding 1,2,4-trithiolane. Thiopivalophenone and thiopivalophenone S-oxides reacted with L. R. at rt to give the corresponding S-sulfide, which further reacted with thiones to afford the corresponding cis-1,2,4-trithiolanes.
A Fast and General Route to Ketones from Amides and Organolithium Compounds under Aerobic Conditions: Synthetic and Mechanistic Aspects
Ghinato, Simone,Territo, Davide,Maranzana, Andrea,Capriati, Vito,Blangetti, Marco,Prandi, Cristina
, p. 2868 - 2874 (2021/01/21)
We report that the nucleophilic acyl substitution reaction of aliphatic and (hetero)aromatic amides by organolithium reagents proceeds quickly (20 s reaction time), efficiently, and chemoselectively with a broad substrate scope in the environmentally responsible cyclopentyl methyl ether, at ambient temperature and under air, to provide ketones in up to 93 % yield with an effective suppression of the notorious over-addition reaction. Detailed DFT calculations and NMR investigations support the experimental results. The described methodology was proven to be amenable to scale-up and recyclability protocols. Contrasting classical procedures carried out under inert atmospheres, this work lays the foundation for a profound paradigm shift of the reactivity of carboxylic acid amides with organolithiums, with ketones being straightforwardly obtained by simply combining the reagents under aerobic conditions and with no need of using previously modified or pre-activated amides, as recommended.
Light-DrivenN-Heterocyclic Carbene Catalysis Using Alkylborates
Sato, Yukiya,Goto, Yamato,Nakamura, Kei,Miyamoto, Yusuke,Sumida, Yuto,Ohmiya, Hirohisa
, p. 12886 - 12892 (2021/10/29)
Radical-radical coupling, the selective reaction between two different radical species, has contributed to the methodology for connecting bulky units. Light-drivenN-heterocyclic carbene (NHC) organocatalysis is recognized as a state-of-the-art methodology enabling radical-radical coupling. The catalytic process involves forming an acyl azolium intermediate from the NHC catalyst and an acyl donor, followed by single electron reduction of this key intermediate, which is largely dependent on the photoredox catalyst. We designed a radical NHC catalysis in which the direct photoexcitation of a borate to form a high reducing agent facilitated the single electron reduction event. The borate produces an alkyl radical for the single electron transfer process to accomplish the radical-radical coupling. This protocol enables cross-coupling between alkylborates and acyl imidazoles in addition to radical relay-type alkylacylations of alkenes with alkylborates and acyl imidazoles, affording ketones with a broad scope.
N-Heterocyclic Carbene-Catalyzed Decarboxylative Alkylation of Aldehydes
Ishii, Takuya,Kakeno, Yuki,Nagao, Kazunori,Ohmiya, Hirohisa
supporting information, p. 3854 - 3858 (2019/04/25)
We found that N-heterocyclic carbene catalysis promoted the unprecedented decarboxylative coupling of aryl aldehydes and tertiary or secondary alkyl carboxylic acid-derived redox-active esters to produce aryl alkyl ketones. The mild and transition-metal-free reaction conditions are attractive features of this method. The power of this protocol was demonstrated by the functionalization of pharmaceutical drugs and natural product. A reaction pathway involving single electron transfer from an enolate form of Breslow intermediate to a redox ester followed by recombination of the resultant radical pair to form a carbon-carbon bond is proposed.
Cp?Co(III)-Catalyzed C-H Alkylation with Maleimides Using Weakly Coordinating Carbonyl Directing Groups
Mandal, Rajib,Emayavaramban, Balakumar,Sundararaju, Basker
supporting information, p. 2835 - 2838 (2018/05/29)
A novel protocol for ortho-C-H alkylation of aromatic and heteroaromatic ketones and esters under Cp?Co(III) catalysis has been developed for the first time. The reaction proceeds through initial cyclometalation via weak chelation-assisted C-H bond activation, followed by coordination of activated alkene, insertion between Co-C, and protodemetalation.
Synthesis of ketones via organolithium addition to acid chlorides using continuous flow chemistry
Moon, Soo-Yeon,Jung, Seo-Hee,Bin Kim,Kim, Won-Suk
, p. 79385 - 79390 (2015/10/06)
An efficient method for the synthesis of ketones using organolithium and acid chlorides under continuous flow conditions has been developed. In contrast to standard batch chemistry, over-addition of the organolithium to the ketone for the formation of the undesired tertiary alcohol has been minimised representing a direct approach toward ketones.
Chemoselective oxidation by electronically tuned nitroxyl radical catalysts
Hamada, Shohei,Furuta, Takumi,Wada, Yoshiyuki,Kawabata, Takeo
supporting information, p. 8093 - 8097 (2013/08/23)
Electronic tuning: Nitroxyl radical 1 is shown to be an efficient catalyst for the oxidation of secondary alcohols, and promotes oxidation through an oxoammonium species which is highly reactive because of the adjacent electron-withdrawing ester groups. Chemoselective oxidation of benzylic alcohols in the presence of aliphatic alcohols is observed and is proposed to proceed by a rate-determining hydride transfer. Copyright
Synthesis of α-indanones via intramolecular direct arylation with cyclopropanol-derived homoenolates
Rosa, David,Orellana, Arturo
, p. 1922 - 1924 (2012/03/11)
A palladium-catalysed, tandem cyclopropanol rearrangement and direct arylation approach for the synthesis of 1-indanones is reported. The reaction is generally high yielding, uses oxygen as the terminal oxidant and tolerates a range of functional groups on the aryl ring.
Synthesis of sterically hindered ketones from aldehydes via O-silyl oximes
Kim, Joong-Gon,Mishra, Mithilesh Kumar,Jang, Doo Ok
experimental part, p. 3527 - 3529 (2012/08/29)
A mild and efficient method to synthesize sterically hindered ketones from aldehydes via O-silyl oximes was developed. Treatment of O-triphenylsilylated oximes with alkyl iodides in the presence of triethyl borane afforded the corresponding ketones.
Facile preparation of aromatic ketones from aromatic bromides and arenes with aldehydes
Ushijima, Sousuke,Dohi, Souya,Moriyama, Katsuhiko,Togo, Hideo
scheme or table, p. 1436 - 1442 (2012/03/09)
Aromatic ketones were efficiently prepared in good yields by the reactions of aryl bromides with n-BuLi, followed by the reactions with aromatic aldehydes or aliphatic aldehydes and the subsequent treatment with molecular iodine and K2CO3, in a one-pot method. The same treatment of arenes, instead of aromatic bromides, also provided the corresponding aromatic ketones in good yields. Using these methods, various diaryl ketones and alkyl aryl ketones bearing electron-rich aromatics and electron-deficient aromatics could be prepared efficiently by a simple, transition-metal-free, and therefore environmentally benign experimental procedure.
