- Direct α-Acylation of Alkenes via N-Heterocyclic Carbene, Sulfinate, and Photoredox Cooperative Triple Catalysis
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N-Heterocyclic carbene (NHC) catalysis has emerged as a versatile tool in modern synthetic chemistry. Further increasing the complexity, several processes have been introduced that proceed via dual catalysis, where the NHC organocatalyst operates in concert with a second catalytic moiety, significantly enlarging the reaction scope. In biological transformations, multiple catalysis is generally used to access complex natural products. Guided by that strategy, triple catalysis has been studied recently, where three different catalytic modes are merged in a single process. In this Communication, direct α-C-H acylation of various alkenes with aroyl fluorides using NHC, sulfinate, and photoredox cooperative triple catalysis is reported. The method allows the preparation of α-substituted vinyl ketones in moderate to high yields with excellent functional group tolerance. Mechanistic studies reveal that these cascades proceed through a sequential radical addition/coupling/elimination process. In contrast to known triple catalysis processes that operate via two sets of interwoven catalysis cycles, in the introduced process, all three cycles are interwoven.
- Liu, Kun,Studer, Armido
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supporting information
p. 4903 - 4909
(2021/05/04)
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- 11a-N-tosyl-5-carbapterocarpans: Synthesis, antineoplastic evaluation and in silico prediction of ADMETox properties
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11a-N-tosyl-5-carbapterocarpans (5a–c and 6a–c), 9-N-tosyl-4,4a,9,9a-tetrahydro-3H-carbazole (7), 11a-N-tosyl-5-carbapterocarpen (8) analogues of LQB-223 (4a), were synthesized through palladium catalyzed azaarylation of substituted dihydronaphtalenes (14a–c) and cyclohexadiene (15), respectively, with N-tosyl-o-iodoaniline (11). In order to understand the role of the N-tosyl moiety for the pharmacological activity, the azacarbapterocarpen (9) was also synthesized by Fischer indol reaction. The structural requirements at the A and D-rings for the antineoplastic activity toward human leukemias and breast cancer cells were evaluated as well. Substitutions on the A-ring of 4a and analogues alter the effect on different breast cancer subtypes. On the other hand, A-ring is not essential for antileukemic activity since compound 7, which does not contain the A-ring, showed efficacy with high selectivity indices for drug-resistant leukemias. On the other hand, substitutions on the D-ring of 4a for fluorine or iodine did not improve the antileukemic activity. In silico studies concerning Lipinskís rule of five, ADMET properties and drug scores of those compounds were performed, indicating good physicochemical properties for all compounds, in special for compound 7.
- Mendes, Joseane A.,Salustiano, Eduardo J.,Pires, Carulini de S.,Oliveira, Thaís,Barcellos, Julio C.F.,Cifuentes, Jhonny M.C.,Costa, Paulo R.R.,Rennó, Magdalena N.,Buarque, Camilla D.
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p. 585 - 590
(2018/07/29)
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- Deoxygenation of carbonyl compounds using an alcohol as an efficient reducing agent catalyzed by oxo-rhenium complexes
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This work describes the first methodology for the deoxygenation of carbonyl compounds using an alcohol as a green solvent/reducing agent catalyzed by oxo-rhenium complexes. The system 3-pentanol/ReOCl3(SMe2)(OPPh3) was successfully employed in the deoxygenation of several aryl ketones to the corresponding alkenes and also in the deoxygenation of aryl aldehydes to alkanes with moderate to excellent yields. The catalyst ReOCl3(SMe2)(OPPh3) can also be used in several catalytic cycles with good activity.
- Bernardo, Joana R.,Fernandes, Ana C.
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supporting information
p. 2675 - 2681
(2016/05/24)
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- Synthesis of 11a- N -Arylsulfonyl-5-carbapterocarpans (Tetrahydro-5 H -benzo[ a ]carbazoles) by Azaarylation of Dihydronaphthalenes with o -Iodo- N -(Arylsulfonyl)anilines in Poly(ethylene glycol)
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11a-N-Arylsulfonyl-5-carbapterocarpans (tetrahydro-5H-benzo[a]carbazoles) were synthesized by palladium-catalyzed azaarylation of dihydronaphthalenes with o-iodo-N-(arylsulfonyl)anilines in poly(ethylene glycol) (PEG-400). Better chemical yields (moderate
- Barcellos, Julio C. F.,Borges, Beatriz H. F.,Mendes, Joseane A.,Ceron, Mauricio C.,Buarque, Camilla D.,Dias, Ayres G.,Costa, Paulo R. R.
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supporting information
p. 3013 - 3019
(2015/09/28)
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- Dioxomolybdenum Complexes as Excellent Catalysts for the Deoxygenation of Aryl Ketones to Aryl Alkenes
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This work describes a new methodology for the selective deoxygenation of aryl ketones to the corresponding aryl alkenes catalyzed by dioxomolybdenum complexes using silanes as reducing agents. The best results were obtained with the system PhSiH3/MoO2Cl2(H2O)2 (5-10 mol %), which was very efficient for the deoxygenation of a large variety of aryl ketones to alkenes in excellent yields. This new methodology has the advantages of using an inexpensive, environmentally friendly, easily prepared, and air-stable catalyst in ether solution.
- Fernandes, Tiago A.,Fernandes, Ana C.
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p. 3503 - 3507
(2015/11/10)
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- Acid catalysed reaction of indanones, tetralones and benzosuberone with neopentyl glycol and other alkanediols under forced conditions
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Upon reaction with an excess of 2,2-dimethylpropane-1,3-diol (neopentyl glycol, NPG) under acid catalysis, indanones and tetralones yield indenes and dihydronaphthalenes, respectively. The reaction can also be carried out with butane-1,3-diol.
- Imai, Masao,Morais, Goreti Ribeiro,Al-Hindawi, Bassam,Al-Sulaibi, Mazen A.M.,Meetani, Mohammad,Thiemann, Thies
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experimental part
p. 325 - 329
(2010/10/19)
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- Tandem Friedel-Crafts annulation to novel perylene analogues
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(Chemical Equation Presented) Novel dialkyloxy- and dihydroxyoctahydroperylenes are regioselectively available via a new tandem Friedel-Crafts alkylation of tetrahydronaphthalene precursors followed by oxidative aromatization. Heating of 5-alkyloxy-1-tetralol with p-toluenesulfonic acid in sulfolane gave the corresponding octahydroperylenes in moderate yields. Studies with Lewis acids and tetralin-1,5-diol in acetonitrile at room temperature provided the 4,10-dihydroxy analogue cleanly, albeit in reduced yields. Examples of these new series of perylene analogues were partially oxidized to the corresponding contiguously aromatic, anthracene core products or fully aromatized to 3,9-dialkyloxyperylenes in good yields.
- Penick, Mark A.,Mahindaratne, Mathew P. D.,Gutierrez, Robert D.,Smith, Terrill D.,Tiekink, Edward R. T.,Negrete, George R.
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p. 6378 - 6381
(2008/12/22)
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- Intramolecular electrophilic aromatic substitution reactions with methyl vinyl ethers for the synthesis of dihydronaphthalenes
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A simple and inexpensive method to effect the conversion of 4-arylalk-1-en-1-yl methyl ethers to dihydronaphthalenes has been developed. Cyclisation is accomplished by warming a toluene solution of the substrate with 1,2-ethanediol and para-toluenesulfonic acid and proceeds via in situ formation of a 1,3-dioxolane. Reactions generally give good yields and have been successful with electron rich, unsubstituted and halogenated arenes. They display excellent regioselectivity; appearing to follow the course of lowest steric demand.
- Harrowven, David C,Tyte, Melloney J
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p. 5971 - 5972
(2007/10/03)
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- Cross coupling of vinyl triflates and alkyl Grignard reagents catalyzed by niekel(0)-complexes
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The scope and limitations of the Nickel(0)-catalyzed cross coupling of vinyl triflates with alkyl Grignard reagents have been studied. The effect of triflate substitution, solvent, and especially ligands have been examined. Ligands which are successful for sp2 and sp Grignard reagents fail for sp3 Grignard reagents.
- Busacca, Carl A.,Eriksson, Magnus C.,Fiaschi, Rita
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p. 3101 - 3104
(2007/10/03)
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- Synthesis and dopamine receptor affinities of 1-aminoethylhetero-tetralines
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A series of 1-aminoethylhetero-tetralines 3-6, which can be considered as opened-structure analogues of previously studied dopaminergic compounds 2, were synthesized.In the binding studies, to evaluate D-1 and D-2 activity, no significant affinity was observed towards both dopaminergic receptors.D-1 receptors / D-2 receptors / dopamine / binding / tetralines
- Perrone, R,Berardi, F,Tortorella, V,Govoni, S,Lograno, MD,Daniele, E
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p. 869 - 874
(2007/10/02)
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- Benoz-fused cycloalkane trans-1,2-diamine derivatives
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Benzo-fused cycloalkane and oxa- and thia-cycloalkane trans-1,2-diamine compounds of the formula: STR1 wherein A, B, C, D, n, X, Y, R, R1, R2 and R3 are as defined in the specification, e.g., trans-3,4-dichloro-N-methyl-N-
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- Synthesis and Dopaminergic Activity of 2-Substituted Octahydrobenzoquinolines
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A series of 2-substituted octahydrobenzoquinolines has been synthesized and assayed for dopamine agonist activity.Only the compounds corresponding to the β-rotameric conformation of dopamine showed biphasic activity in competition binding studies with the radioligand spiroperidol.These findings suggest that the congeners possessing the β-rotamer conformation show receptor-binding characteristics that resemble those of the ergolines more closely than do those of the corresponding α-rotamer congeners.
- Craig, J. Cymerman,Torkelson, Steven M.,Findell, Paul R.,Weiner, Richard I.
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p. 961 - 968
(2007/10/02)
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- Automerization of Propella-2,4,7,9-tetraene. Intermediacy of a Cyclobutadiene Derivative and Its Trapping by Methanol
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Automerization of propella-2,4,7,9-tetraene system proceeds via a cyclobutadiene intermediate, which is trapped by methanol
- Tsuji, Takashi,Nishida, Shinya
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p. 1389 - 1392
(2007/10/02)
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- Simple Preparation of β-Tetralones and β-Indanones by a 1,2-Carbonyl Group Transposition
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By a four-step procedure, the ketones 3 are converted into the β-tetralones 7a-d and the β-indanones 7e, f via the intermediates 4, 5, and 6.
- Braun, Manfred,Bernhard, Carlo
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p. 435 - 437
(2007/10/02)
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