17257-10-2Relevant articles and documents
A straightforward alkynylation of Li and Mg metalated heterocycles with sulfonylacetylenes
Marzo, Leyre,Prez, Ignacio,Yuste, Francisco,Alemn, Jos,Garca Ruano, Jos Luis
supporting information, p. 346 - 349 (2015/02/05)
Coupling of alkynyl moieties to heterocyclic rings, without using transition metals, can be easily performed by the reaction of aryl or heteroaryl sulfonylacetylenes with heteroaryl-Li compounds or their corresponding less reactive magnesium derivatives.
Palladium-catalyzed regioselective allylation of five-membered heteroarenes with allyltributylstannane
Zhang, Sheng,Yu, Xiaoqiang,Feng, Xiujuan,Yamamoto, Yoshinori,Bao, Ming
supporting information, p. 3842 - 3845 (2015/03/30)
Palladium-catalyzed allylation reactions of 2-(chloromethyl)thiophenes, 2-(chloromethyl)furans, and N-protected 2-(chloromethyl)-1H-pyrroles with allyltributylstannane were described in this study. This type of allylation reaction regioselectively occurred on the heteroarene rings to produce allylated dearomatization products or allylated heteroarenes with satisfactory yields.
Palladium-catalyzed oxidative cross-coupling between heterocycles and terminal alkynes with low catalyst loading
Jie, Xiaoming,Shang, Yaping,Hu, Peng,Su, Weiping
supporting information, p. 3630 - 3633 (2013/04/23)
Direct: With [Pd2(dba)3] as a catalyst, the direct alkynylation of thiophenes bearing a variety of substituents has been accomplished by using terminal alkynes as alkynylating reagents. This protocol is also applicable to other electron-rich aromatic heterocycles. dba=dibenzylidenacetone. Copyright
Double elimination protocol for the synthesis of arylene ethynylenes containing heteroaromatic rings
Orita, Akihiro,Ye, Fangguo,Babu, Govindarajulu,Ikemoto, Tomohiro,Otera, Junzo
, p. 716 - 727 (2007/10/03)
The double elimination reaction of β-substituted sulfones offers a versatile strategy for synthesis of arylene ethynylene kits containing heteroaromatic rings. A sequence of aldol reaction between α-sulfonyl carbanion and aldehyde, trapping the resulting aldolate to give β-substituted sulfone, and double elimination of this intermediate can be integrated in one pot. This protocol allows thiophene, pyridine, and ferrocene units to be accommodated in phenylene ethynylene arrays.
Facile one-pot coupling - Aminovinylation approach to push - Pull chromophores: Alkyne activation by sonogashira coupling
Karpov, Alexei S.,Rominger, Frank,Mueller, Thomas J. J.
, p. 1503 - 1511 (2007/10/03)
A straightforward coupling - aminovinylation sequence of terminal alkynes 1, electron-deficient heteroaryl halides 2, and secondary amines 4 furnishes highly solvochromic push-pull chromophores 5 in good yields. Semiempirical calculations (PM3) suggest that the aminovinylation proceeds in a stepwise fashion through a zwitterionic intermediate with a final rate-determining intramolecular protonation. Crucial parameters for the success of the amine addition are the relative LUMO energies and the charge distribution at the Β-alkynyl carbon atom.
Palladium-Catalyzed Arylation of Polar Organometallics Mediated by 9-Methoxy-9-Borabicyclononane: Suzuki Reactions of Extended Scope
Fuerstner, Alois,Seidel, Guenter
, p. 11165 - 11176 (2007/10/02)
An alternative way for performing Suzuki reactions is presented.The necessary borate is the actual nucleophile in these palladium catalyzed C-C-bond formations is prepared from 9-methoxy-9-borabicyclononane (9-OMe-9-BBN) and a polar organometallic reagent RM, and not as usually from a borane and a base.This approach allows cross couplings of aryl halides with e.g. alkynyl-, methyl-, or TMSCH2-groups, which were beyond the scope of the conventional Suzuki reaction.The method is highly chemoselective and turned out to be compatible with aldehyde-, amide-, ketone-, ester- and cyano functions as well as with basic nitrogen atoms in the substrates.It was applied to the synthesis of the acetylenic natural products junipal (9a) and eutypine methyl ether (10).Since 11B NMR studies revealed that the 9-OMe-9-BBN only serves as a shuttle for delivering the RM reagent but remains unchanged during the course of the reaction, it has been possible to device the first Suzuki-type reaction sub-stoichiometric in boron.This "catalytic" protocol was used to prepare compound 8 which is highly valuable for its chemoluminescence properties.
Photochemical Reactivity of Halofuran and Halothiophene Derivatives in the Presence of Arylalkenes and Arylalkynes
D'Auria, Maurizio,Piancatelli, Giovanni,Ferri, Tommaso
, p. 4019 - 4025 (2007/10/02)
The photochemical reactions of 5-iodothiophene-2-carbaldehyde (4a), 2-acetyl-5-iodothiophene (4b), 5-bromofuran-2-carbaldehyde (3b) with arylalkenes 5 (styrene), 7 (2-vinylthiophene), 10 (2-vinylfuran), 12 (4-methyl-5-vinylthiazole), and 16 (benzofuran) are reported.All of the reactions give the corresponding substitution products as a cis-trans mixture.The photochemical reaction of 4a and 4c (methyl 5-iodothiophene-2-carboxylate) with arylalkynes is also reported: in this case the reaction of 4a and 4c with phenylacetylene (18) furnishes the substitution products (19 and 26, respectively) deriving from an attack on the alkyne moiety, while the reaction with 2-ethynylthiophene (20) and 2-ethynylfuran (23) furnishes a mixture deriving from the attack both on the alkyne and on the heterocyclic ring.The ratio between these two products can be modified by changing the concentrations of the reagents.The mechanism of these reactions is discussed on the basis of photochemical and electrochemical properties of the reagents in terms of an electron-transfer process.The experimental results are explained in terms of ΔG values, and they are in agreement with the formation of both a solvent-separated pair and a contact radical ion pair.
