28748-41-6Relevant academic research and scientific papers
Copper-catalyzed direct alkylation of heteroarenes
Theunissen, Cédric,Wang, Jianjun,Evano, Gwilherm
, p. 3465 - 3470 (2017/07/11)
An efficient and broadly applicable process is reported for the direct alkylation of C-H bonds in heteroarenes, privileged scaffolds in many areas of science. This reaction is based on the copper-catalyzed addition of alkyl radicals generated from activated secondary and tertiary alkyl bromides to a wide range of arenes, including furans, thiophenes, pyrroles, and their benzo-fused derivatives, as well as coumarins and quinolinones.
The Selective Cross-Coupling of Secondary Alkyl Zinc Reagents to Five-Membered-Ring Heterocycles Using Pd-PEPPSI-IHeptCl
Atwater, Bruce,Chandrasoma, Nalin,Mitchell, David,Rodriguez, Michael J.,Pompeo, Matthew,Froese, Robert D. J.,Organ, Michael G.
supporting information, p. 9502 - 9506 (2015/08/11)
The ability to cross-couple secondary alkyl centers is fraught with a number of problems, including difficult reductive elimination, which often leads to β-hydride elimination. Whereas catalysts have been reported that provide decent selectivity for the expected (non-rearranged) cross-coupled product with aryl or heteroaryl oxidative-addition partners, none have shown reliable selectivity with five-membered-ring heterocycles. In this report, a new, rationally designed catalyst, Pd-PEPPSI-IHeptCl, is demonstrated to be effective in selective cross-coupling reactions with secondary alkyl reagents across an impressive variety of furans, thiophenes, and benzo-fused derivatives (e.g., indoles, benzofurans), in most instances producing clean products with minimal, if any, migratory insertion for the first time. A wide variety of five-membered-ring heterocycles were successfully cross-coupled to secondary alkyl zinc reagents with the new precatalyst Pd-PEPPSI-IHeptCl, which features a bulky N-heterocyclic carbene ligand. This catalyst suppresses migratory-insertion (rearrangement) pathways, and the desired products are thus formed with high selectivity.
Cobalt-Catalyzed Negishi Cross-Coupling Reactions of (Hetero)Arylzinc Reagents with Primary and Secondary Alkyl Bromides and Iodides
Hammann, Jeffrey M.,Haas, Diana,Knochel, Paul
supporting information, p. 4478 - 4481 (2015/04/14)
We report a cobalt-catalyzed cross-coupling of di(hetero)arylzinc reagents with primary and secondary alkyl iodides or bromides using THF-soluble CoCl2·2 LiCl and TMEDA as a ligand, which leads to the corresponding alkylated products in up to 88% yield. A range of functional groups (e.g. COOR, CN, CF3, F) are tolerated in these substitution reactions. Remarkably, we do not observe rearrangement of secondary alkyl iodides to unbranched products. Additionally, the use of cyclic TBS-protected iodohydrins leads to trans-2-arylcyclohexanol derivatives in excellent diastereoselectivities (up to d.r.=99:1).
INDOLE DERIVATIVES USEFUL AS CCR2 ANTAGONISTS
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Page/Page column 41, (2012/10/07)
Disclosed are the CCR2 antagonists of Formula I: I or pharmaceutically acceptable salt thereof wherein R7, A, X, B, and n are defined herein. Also disclosed are pharmaceutical compositions containing the compounds, methods of treatment using the compounds
Ruthenium NHC catalyzed highly asymmetric hydrogenation of benzofurans
Ortega, Nuria,Urban, Slawomir,Beiring, Bernhard,Glorius, Frank
supporting information; experimental part, p. 1710 - 1713 (2012/04/05)
H2-O-T! Aromatic O-heterocycles are a challenging substrates for asymmetric hydrogenation (H2). An in situ formed chiral N-heterocyclic carbene (NHC) ruthenium complex allows the high yielding, completely regioselective, and highly asymmetric hydrogenation of substituted benzofurans at room Temperature, giving valuable 2,3-dihydrobenzofurans (see scheme). Copyright
Alkene isomerization/enamide-ene and diene metathesis for the construction of indoles, quinolines, benzofurans and chromenes with a chiral cyclopropane substituent
Kobayashi, Takaaki,Arisawa, Mitsuhiro,Shuto, Satoshi
, p. 1219 - 1224 (2011/04/15)
A synthetic method for bicyclic heterocycles, such as indole, benzofuran and chromene derivatives bearing a chiral cyclopropane at the 2-position, was established using isomerization of a terminal olefin and enamide-ene or diene metathesis. This route can also be applied to chiral 2-cyclopropylquinoline synthesis (both cis and trans).
4- [HETEROCYCLYL-METHYL] -8-FLUORO-QUINOLIN-2-ONES USEFUL AS NITRIC OXIDE SYNTHASE INHIBITORS
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Page/Page column 63, (2009/04/25)
Novel compounds of formulae (II, III) and pharmaceutical compositions have been found to inhibit inducible NOS synthase wherein: R4, R5, R6 and R7 are independently selected from the group consisting of hydrogen, lower alkyl, and halogen; and, R8 has the structure whrein X1, X2, X3, X4, X5, X6, R9, R13, R14 and n are as described herein.
Novel Routes to 1-Aryl-1,4-dihydro-3(2H)-isoquinolinones and 2-Substituted or 2,3-Disubstituted Benzofurans by Intramolecular Cyclizations
Katritzky, Alan R.,Lan, Xiangfu,Zhang, Zhongxing
, p. 381 - 387 (2007/10/02)
N-(α-Benzotriazolylalkyl)arylacetamides, readily available from an arylacetamide, an aldehyde and benzotriazole, undergo intramolecular cyclization under acidic conditions to give 1-aryl-1,4-dihydro-3(2H)-isoquinolinones in good to excellent yields.Similarly, 2-(benzotriazol-1-yl)-2-(o-hydroxyphenyl)ethanols, obtained by lithiation of 2-(benzotriazol-1-ylmethyl)phenols followed by quenching with aldehydes or ketones, eliminate a molecule of water and a molecule of benzotriazole yielding 2-substituted and 2,3-disubstituted benzofurans.
REARRANGEMENTS DE DIHYDRO-2,3 BENZO-b FURANNES α VINYLIQUES EN MILIEU ACIDE: ACCES A DES BENZO-b FURANNES ET 2H-BENZO-b PYRANNES
David, M.,Sauleau, J.,Sauleau, A.
, p. 3587 - 3594 (2007/10/02)
Neighbouring alkene group participation, resulting in isomerization, has been studied in reactions of some 2,3-dihydrobenzofurans with hydrobromic acid (in acetic acid) and with paratoluene sulfonic acid (in benzene).It was found that these 2-vinyl cyclic ethers afford benzo-b furans and Δ 3-chromenes; the ratio of five-to six membered ring products depending upon the rection conditions and upon the number of methyl groups at the double bond.
REDUCTION PAR LES SELS CHROMEUX DE BROMURES BENZYLIQUES ORTHO-O-ACYLES AVEC TRANSPOSITION DU GROUPEMENT ACYLE DE L'ESTER: ACCES AUX ORTHO-HYDROXYBENZYL CETONES NON MASQUEES ET UNE NOUVELLE PREPARATION DE BENZO(B)FURANNES SUBSTITUES EN POSITION-2
Ledoussal, B.,Gorgues, A.,Coq, A. Le
, p. 5841 - 5852 (2007/10/02)
The ?-bonded organochromium (III) complexes resulting from the reduction of ortho-O-acyl benzylic bromides 1 with CrCl2 undergo an 1,5-transposition of the ester acyl functional group which allows, through selected experimental conditions either a selective access to the unmasked ortho-hydroxybenzyl ketones 2 or a new preparation of the 2-substituted benzofurans 3.The scope and limitations of the method are presented.
