22591-15-7Relevant academic research and scientific papers
Enantioselective Protonation of Silyl Enol Ethers Catalyzed by a Chiral Pentacarboxycyclopentadiene-Based Bronsted Acid
An, Shaoyu,Li, Jun,Li, Pingfan,Yuan, Chao
supporting information, p. 1317 - 1320 (2019/06/19)
The enantioselective protonation of silyl enol ethers was realized in the presence of a pentacarboxycyclopenta-1,3-diene-based chiral Bronsted acid catalyst with water as an achiral proton source to give the corresponding α-aryl ketones in good yields and up to 75percent ee.
Direct Asymmetric α-Hydroxylation of Cyclic α-Branched Ketones through Enol Catalysis
Shevchenko, Grigory A.,Pupo, Gabriele,List, Benjamin
supporting information, p. 49 - 53 (2019/01/04)
Enantiopure α-hydroxy carbonyl compounds are common scaffolds in natural products and pharmaceuticals. Although indirect approaches towards their synthesis are known, direct asymmetric methodologies are scarce. Herein, we report the first direct asymmetric α-hydroxylation of α-branched ketones through enol catalysis, enabling a facile access to valuable α-keto tertiary alcohols. The transformation, characterized by the use of nitrosobenzene as the oxidant and a new chiral phosphoric acid as the catalyst, delivers a good scope and excellent enantioselectivities.
A three-step process to facilitate the annulation of polycyclic aromatic hydrocarbons
Martin, Sara E.,Streeter, Matthew D.,Jones, Laurel L.,Klepfer, Matthew S.,Atmatzidis, Kyriakos,Wille, Kristen D.,Harrison, Sean A.,Hoegg, Edward D.,Sheridan, Heather M.,Kramer, Stephanie,Parrish, Damon A.,Amick, Aaron W.
, p. 8324 - 8330 (2015/03/18)
A new efficient three-step process to annulate polycyclic aromatic hydrocarbons (PAHs) has been developed, providing access to PAHs with saturated rings that under current chemical methods would be difficult to produce in an efficient manner. This method relies on a palladium-catalyzed cross-coupling reaction of various brominated PAHs with cyclohexanone to yield α-arylated ketones, which are converted to regiospecific vinyl triflates and cyclized by a palladium-catalyzed intramolecular arene-vinyl triflate coupling to produce PAHs with incorporated saturated rings or "tetrahydroindeno-annulated" PAHs.
Development of a new Lewis base-tolerant chiral LBA and its application to catalytic asymmetric protonation reaction
Cheon, Cheol Hong,Imahori, Tatsushi,Yamamoto, Hisashi
supporting information; experimental part, p. 6980 - 6982 (2010/11/02)
A new Lewis base-tolerant LBA (Lewis Acid Assisted Bronsted Acid) derived from La(OTf)3 and (S)-HOP has been developed as a new chiral Bronsted acid. This acid has been successfully applied as a catalyst to asymmetric protonation reactions of silyl enol ethers of 2-substituted cyclic ketones.
A convenient synthesis of 2-naphthylcyclopentanones and 2-naphthylcyclohexanones from 1-naphthylcycloalkenes
Gora, Maciej,Luczynski, Michal K.,Sepiol, Janusz J.
, p. 1625 - 1630 (2007/10/03)
The oxidation of naphthylcycloalkenes with hydrogen peroxide or MCPBA followed by acid catalyzed rearrangement of diol (epoxide), afforded a series of naphthylcycloalkanones in a very simple manner. The conditions allow preparation of naphthylcycloalkanones on a multigram scale. Georg Thieme Verlag Stuttgart.
Palladium-catalyzed intramolecular hydroalkylation of alkenyl- β-keto esters, α-aryl ketones, and alkyl ketones in the presence of Me 3SiCl or HCI
Han, Xiaoqing,Wang, Xiang,Pei, Tao,Widenhoefer, Ross A.
, p. 6333 - 6342 (2007/10/03)
Reaction of 3-butenyl β-keto esters or 3-butenyl α-aryl ketones with a catalytic amount of [PdCl2(CH3CN)2] (2) and a stoichiometric amount of Me3SiCl or Me3SiCl/ CuCl2 in dioxane at 25-70°C formed 2-substituted cyclohexanones in good yield with high regioselectivity. This protocol tolerated a number of ester and aryl groups and tolerated substitution at the allylic, enolic, and cis and trans terminal olefinic positions. In situ NMR experiments indicated that the chlorosilane was not directly involved in palladium-catalyzed hydroalkylation, but rather served as a source of HCl, which presumably catalyzes enolization of the ketone. Identification of HCl as the active promoter of palladium-catalyzed hydroalkylation led to the development of an effective protocol for the hydroalkylation of alkyl 3-butenyl ketones that employed sub-stoichiometric amounts of 2, HCl, and CuCl2 in a sealed tube at 70°C.
Palladium-catalyzed intramolecular hydroalkylation of unactivated olefins with dialkyl ketones
Wang, Xiang,Pei, Tao,Han, Xiaoqing,Widenhoefer, Ross A.
, p. 2699 - 2701 (2007/10/03)
(Matrix presented) Treatment of 3-butenyl heptyl ketone with substoichiometric amounts of PdCl2(CH3CN)2 (10 mol%), HCl (0.1 equiv), and CuCl2 (0.3 equiv) in dioxane at 70°C for 12 h in a sealed tube formed 2-hexylcyclohexanone in 77% isolated yield. A number of alkyl 3-butenyl ketones underwent hydroalkylation under these conditions to form 2-substituted cyclohexanones in moderate to good yield.
New method for the preparation of 2-aryl-and 2-heteroarylcyclohexanones. Synthesis of 6,7,8,9-tetrahydro-5H-1,3-dioxolo[4,5-b]carbazole
Santos, Roberto P.,Lopes, Rosangela S. C.,Lopes, Claudio C.
, p. 845 - 848 (2007/10/03)
2-Aryl- and 2-heteroarylcyclohexanones were prepared through 1,4-addition of lithiated species to 1-nitro-1-cyclohexene followed by Nef reaction in good yields. As a synthetic application of this method, 6,7,8,9-tetrahydro-5H-1,3-dioxolo[4,5-b]carbazole was synthesized.
