890098-06-3Relevant academic research and scientific papers
Carbonylative Suzuki-Miyaura couplings of sterically hindered aryl halides: Synthesis of 2-aroylbenzoate derivatives
Bayer, Annette,Ismael, Aya,Skrydstrup, Troels
supporting information, p. 1754 - 1759 (2020/03/17)
We have developed a carbonylative approach to the synthesis of diversely substituted 2-aroylbenzoate esters featuring a new protocol for the carbonylative coupling of aryl bromides with boronic acids and a new strategy to favour carbonylative over non-carbonylative reactions. Two different synthetic pathways-(i) the alkoxycarbonylation of 2-bromo benzophenones and (ii) the carbonylative Suzuki-Miyaura coupling of 2-bromobenzoate esters-were evaluated. The latter approach provided a broader substrate tolerance, and thus was the preferred pathway. We observed that 2-substituted aryl bromides were challenging substrates for carbonylative chemistry favouring the non-carbonylative pathway. However, we found that carbonylative Suzuki-Miyaura couplings can be improved by slow addition of the boronic acid, suppressing the unwanted direct Suzuki coupling and, thus increasing the yield of the carbonylative reaction.
Substitution controlled functionalization of ortho -bromobenzylic alcohols via palladium catalysis: Synthesis of chromenes and indenols
Mahendar, Lodi,Satyanarayana, Gedu
, p. 2059 - 2074 (2014/04/03)
An efficient domino Pd-catalyzed transformation of simple ortho-bromobenzyl tertiary alcohols to chromenes is presented. Their formation is believed to proceed via the formation of a five-membered palladacycle, which, in turn, involves in an intermolecular homocoupling with the second ortho- bromobenzyltertiary alcohol to yield the homo-biaryl bond followed by intramolecular C-O bond formation. Interestingly, when there is an allylic substituent on the benzylic carbon atom, a chemoselective switch was observed, which preferred intramolecular Heck coupling and gave indenols. Further, it has been confirmed that the tertiary alcohol functionality is indispensible to give the coupled products, whereas the use of primary/secondary benzylic alcohols furnished the simple carbonyl products via a possible reductive debromination followed by oxidation due to the availability of β-hydrogen(s).
CuII-catalyzed asymmetric hydrosilylation of diaryl- and aryl heteroaryl ketones: Application in the enantioselective synthesis of orphenadrine and neobenodine
Sui, Yao-Zong,Zhang, Xi-Chang,Wu, Jun-Wen,Li, Shijun,Zhou, Ji-Ning,Li, Min,Fang, Wenjun,Chan, Albert S. C.,Wu, Jing
supporting information; experimental part, p. 7486 - 7492 (2012/07/27)
With certain amounts of sodium tert-butoxide and tert-butanol as additives, catalytic amounts of an inexpensive and easy-to-handle copper source Cu(OAc)2·H2O, a commercially available and air-stable non-racemic dipyridylphosphine ligand, as well as the stoichiometric desirable hydride donor polymethylhydrosiloxane (PMHS), formed a versatile in situ catalyst system for the enantioselective reduction of a broad spectrum of prochiral diaryl and aryl heteroarylketones in air, in high yields and with good to excellent enantioselectivities (up to 96 %). In particular, the practical viability of this process was evinced by its successful applications in the asymmetric synthesis of optically enriched potent antihistaminic drugs orphenadrine and neobenodine. Copyright
Trans-chelating ligands in palladium-catalyzed carbonylative coupling and methoxycarbonylation of aryl halides
Kaganovsky, Luba,Gelman, Dmitri,Rueck-Braun, Karola
experimental part, p. 260 - 266 (2010/03/26)
The manuscript describes the use of a trans-chelated palladium complex derived from 1,8-bis-(4-(diphenylphosphino)phenyl)anthracene (1) and p-TolPdI(TMEDA) as a precatalyst in carbonylative Suzuki coupling and methoxycarbonylation of aryl iodides and bromides. The catalyst is active in 0.01-1 mol% loading and demonstrates highly selective transformations. The selectivity is attributed to the unique structural features of the trans-chelating ligands.
Synthesis of 1,3-Diaryl-2-methoxyindenes by hydriodic acid-catalyzed cyclization of Aryl[2-(1-aryl-2-methoxyvinyl)phenyl]methanols
Kobayashi, Kazuhiro,Shirai, Yuu,Nagaoka, Toshiyuki,Konishi, Hisatoshi
experimental part, p. 2866 - 2881 (2009/12/03)
An efficient two-step method for the synthesis of 1,3-diaryl-2- methoxyindenes from 1-(1-aryl-2-methoxyvinyl)-2-bromobenzenes has been developed. Thus, the reaction of 2-(1-aryl-2-methoxyvinyl)phenyllithiums, generated in situ by halogen-lithium exchange between 1-(1-aryl-2-methoxyvinyl)- 2-bromobenzenes and butyllithium, with aromatic aldehydes gives aryl[2-(1-aryl-2-methoxyvinyl)phenyl]methanols, which in turn are treated with a catalytic amount of concentrated hydriodic acid to afford the corresponding 1,3-diaryl-2-methoxyindenes in reasonable yields.
Photoinduced C-Br homolysis of 2-bromobenzophenones and Pschorr ring closure of 2-aroylaryl radicals to fluorenones
Moorthy, Jarugu Narasimha,Samanta, Subhas
, p. 9786 - 9789 (2008/03/17)
(Chemical Equation Presented) A variety of diversely substituted 2-aroylaryl radicals, generated by photoinduced homolysis of 2-bromoarylketones, is shown to undergo Pschorr cyclization to yield fluorenones in moderate to excellent yields. The photochemical results illustrate that the substituents in the two phenyl rings of the 2-bromobenzophenone skeleton exert a dramatic influence on the reactivity of the derived 2-aroylaryl radicals. The disubstitution by methoxy groups in the radical ring renders the aryl σ-radical highly electrophilic and unreactive for hydrogen abstraction and cyclization. On the other hand, the substituents in the non-radical ring that strongly stabilize the hydrofluorenyl π-radical, formed subsequent to the attack of the 2-aroylaryl radical on the non-radical ring, promote cyclization to furnish fluorenones in excellent isolated yields.
