60166-84-9Relevant academic research and scientific papers
Tandem versus single C-C bond forming reaction under palladium-copper catalysis: regioselective synthesis of α-pyrones fused with thiophene
Raju, Sirisilla,Batchu, Venkateswara Rao,Swamy, Nalivela Kumara,Dev, R. Vasu,Sreekanth, Bukkapattanam R.,Babu, J. Moses,Vyas,Kumar, P. Rajender,Mukkanti,Annamalai, Pazhanimuthu,Pal, Manojit
, p. 9554 - 9570 (2006)
We herein report a highly convenient protocol for rapid construction of α-pyrone fused with thiophene. This includes one-pot and regioselective synthesis of 4,5-disubstituted and 5-substituted thieno[2,3-c]pyran-7-ones, 6,7-disubstituted and 6-substituted thieno[3,2-c]pyran-4-ones. The synthesis of thieno[2,3-c]pyran-7-ones involves palladium mediated cross coupling of 3-iodothiophene-2-carboxylic acid with terminal alkynes in a simple synthetic operation. The coupling-cyclization reaction was initially studied in the presence of Pd(PPh3)2Cl2 and CuI in a variety of solvents. 5-Substituted 4-alkynylthieno[2,3-c]pyran-7-ones were isolated in good yields when the reaction was performed in DMF. Similarly, 6-substituted 7-alkynylthieno[3,2-c]pyran-4-ones were synthesized via palladium-catalyzed cross coupling of 2-bromothiophene-3-carboxylic acid with terminal alkynes. A tandem C-C bond forming reaction in the presence of palladium catalyst rationalizes the formation of coupled product in this apparently three-component reaction. The cyclization step of this coupling-cyclization-coupling process occurs in a regioselective fashion to furnish products containing six-membered ring only. This sequential C-C bond forming reaction however, can be restricted to the formation of single C-C bond by using 10% Pd/C-Et3N-CuI-PPh3 as catalyst system in the cross coupling reaction. 5-Substituted thieno[2,3-c]pyran-7-ones were obtained in good yields when the coupling reaction was performed under this condition. Some of the compounds synthesized were tested in vitro for their anticancer activities.
Direct Vicinal Difunctionalization of Thiophenes Enabled by the Palladium/Norbornene Cooperative Catalysis
Li, Renhe,Zhou, Yun,Xu, Xiaolong,Dong, Guangbin
supporting information, p. 18958 - 18963 (2019/12/04)
Herein we report a direct vicinal difunctionalization of thiophenes via the palladium/norbornene (Pd/NBE) cooperative catalysis. A series of mono- and disubstituted thiophenes can be difunctionalized site-selectively and regioselectively at the C4 and C5 positions in good yields, enabled by an arsine ligand and a unique amide-based NBE. The synthetic utility has been shown in derivatizations of complex bioactive compounds and an open-flask gram-scale preparation. Preliminary results have been obtained in the difunctionalization of furans and a direct C4-selective arylation of 2-substituted thiophenes.
N-SULFONYLHETEROCYCLOPYRROLYLALKYLAMINE COMPOUNDS AS 5-HYDROXYTRYPTAMINE-6 LIGANDS
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Page/Page column 22, (2010/02/10)
The present invention provides a compound of formula I and the use thereof for the therapeutic treatment of a CNS disorder relating to or affected by the 5-HT6 receptor.
A new route to the synthesis of bicyclo [3.3.2] nonene by radical cyclisation
Duffault, Jean-Marc,Tellier, Frederique
, p. 2467 - 2481 (2007/10/03)
Radical-induced cyclisation to form 7-membered ring with bicyclic framework was achieved by tributyltin hydride (TBTH) and α, α'-azobis- (isobutyronitrile) (AIBN).
Strategy for a seven-membered ring closure with bicyclic framework
Duffault, Jean-Marc
, p. 33 - 34 (2007/10/03)
Radical-induced cyclisations to form 7-membered rings with bicyclic framework were achieved by tributyltin hydride (TBTH) and α,α′-azobis(isobutyronitrile) (AIBN).
THE BEHAVIOUR OF VICINAL ALKYL AMINOTHIOPHENECARBOXYLATES IN THE SANDMEYER AND SCHIEMANN REACTIONS
Corral, Carlos,Lasso, Ana,Lissavetzky, Jaime,Alvarez-Insua, Alberto Sanchez,Valdeolmillos, Ana M.
, p. 1431 - 1435 (2007/10/02)
The diazotization of vicinal alkyl aminothiophenecarboxylates has been studied. 3-Amino compounds gave clear diazonium salts which yielded the expected halo derivatives in the Sandmeyer and Schiemann conditions.However, 2-amino compounds yielded self-coupling products.
Regioselective α-and β-Metallations of Thiophene Derivatives Bearing the 4,4-Dimethyloxazolin-2-yl Group. Application of the Method to Syntheses of 2,3- and 2,5-Disubstituted Thiophene Derivatives
Carpenter, Andrew J.,Chadwick, Derek J.
, p. 173 - 182 (2007/10/02)
The effects of change of solvent, metallating agent, reaction time and temperature, and of the presence or absence of agents capable of complex formation with either the lithium cation or the oxazoline moiety, on the lithiation of 4,4-dimethyl-2-(2-thienyl)oxazoline are explored.Conditions are thereby established for high-yielding syntheses of the 3- and 5-lithio-intermediates and for control of regioselectivity of metallation.The nucleophilicity of 3-lithio-intermediate is profoundly solvent dependent, and appropriate conditions for reaction of both 3- and 5-lithiated species with a wide variety of electrophiles are presented.Syntheses of a range of 2,3- and 2,5-disubstituted thiophene derivatives have thereby been achieved, utilising, in addition, a new method for the transformation of oxazolino into carboxy functionality.The balance between basicity and nucleophilicity of the 3-lithio-intermediate in its reaction with - and -acetone is shown to be sensitive to isotope effects.
The Scope and Limitations of Carboxamide-Induced β-Directed Metalation of 2-Substituted Furan, Thiophene, and 1-Methylpyrrole Derivatives Application of the Method of Syntheses of 2,3-Disubstituted Thiophenes and Furans
Carpenter, Andrew J.,Chadwick, Derek J.
, p. 4362 - 4368 (2007/10/02)
The effects of change of solvent, metalating agent, reaction time, and reaction temperature on the lithiation of N,N-diethylthiophene-2-carboxamide and of the N-tert-butyl-2-carboxamide derivatives of furan, thiophene, and 1-methylpyrrole are explored, and optimum conditions are established for ring β-directed metalation.The tertiary carboxamido group is less effective in this context than the secondary amide function and appears to be of limited value in these heteroaromatic systems.The high metalation levels achievable with the furan and thiophene secondary amides allow high-yielding syntheses (through reaction of the lithiated intermediates with a wide range of electrophiles) of otherwise inaccessible 2,3-disubstituted derivatives.The synthetical value of the methodology appears to be limited only by the forcing conditions required for amide hydrolysis.
HIGH-YIELD SYNTHESES OF 2,3-DISUBSTITUTED FURANS AND THIOPHENES
Carpenter, Andrew J.,Chadwick, Derek J
, p. 1777 - 1780 (2007/10/02)
The course of lithiation of furan- and thiophene-2-carboxylic acids is critically dependent on the identity of the lithium base allowing high-yielding syntheses of 2,3- and 2,5-disubstituted thiophenenes: the proposed use of a trimethylsilyl blocking group to control metallation in the furan acid provides a useful route to 2,3-disubstituted furans.
