22145-09-1Relevant articles and documents
Pd-catalyzed oxidative homo-coupling of acrylates and aromatic alkenes for the conjugated diene synthesis
Zhu, Ting,Li, Zhen,Xiao, Fanhua,Duan, Wei-Liang
supporting information, p. 3238 - 3241 (2018/07/21)
We developed a bidentate monoanionic nitrogen ligand that was effective in the Pd-catalyzed oxidative homo-coupling reaction of acrylates and aromatic alkenes. In the presence of Pd(OAc)2/ligand several conjugated dienes were obtained in good yields with high stereoselectivities.
Synthesis of Unsymmetric Monosubstituted and Disubstituted Dinaphthothiophenes
Throgmorton, John C.,Chintala, Satyanarayana M.,McCulla, Ryan D.
supporting information, p. 3682 - 3688 (2017/10/09)
Dinaphthothiophenes (DNTs) are a class of compounds with potential uses in organic semiconductors and the synthesis of unsymmetric catalysts. Symmetrical or asymmetrical addition of functional groups to the DNT structure may be desired for steric bulk in binaphthyl catalyst synthesis or tuning the electronic properties of semiconductors. Thus, versatility of functional group addition is a great asset in DNT synthesis. Until now, no versatile and concise methods for the synthesis of unsymmetrically substituted DNTs have been reported. Herein, we report three synthetic routes for the creation of three different classes of DNTs. Each route involves the successive addition of two functionalized styryl groups to a thiophene ring, followed by a photocyclization to form the desired asymmetric DNT. Various novel unsymmetrically monosubstituted and disubstituted dinaphtho[2,1-b:1′,2′-d]thiophenes, dinaphtho[1,2-b:1′,2′-d]thiophenes, and dinaphtho[1,2-b:2′,1′-d]thiophenes were synthesized from 2-bromothiophene,2,4-dibromothiophene, and 3,4-dibromothiophene in three or four steps. These methods can be used to synthesize a wide variety of unsymmetrically functionalized DNTs.
Catalytic Dehydrogenative C-C Coupling by a Pincer-Ligated Iridium Complex
Wilklow-Marnell, Miles,Li, Bo,Zhou, Tian,Krogh-Jespersen, Karsten,Brennessel, William W.,Emge, Thomas J.,Goldman, Alan S.,Jones, William D.
supporting information, p. 8977 - 8989 (2017/07/12)
The pincer-iridium fragment (iPrPCP)Ir (RPCP = ?3-2,6-C6H3(CH2PR2)2) has been found to catalyze the dehydrogenative coupling of vinyl arenes to afford predominantly (E,E)-1,4-diaryl-1,3-butadienes. The eliminated hydrogen can undergo addition to another molecule of vinyl arene, resulting in an overall disproportionation reaction with 1 equiv of ethyl arene formed for each equivalent of diarylbutadiene produced. Alternatively, sacrificial hydrogen acceptors (e.g., tert-butylethylene) can be added to the solution for this purpose. Diarylbutadienes are isolated in moderate to good yields, up to ca. 90% based on the disproportionation reaction. The results of DFT calculations and experiments with substituted styrenes indicate that the coupling proceeds via double C-H addition of a styrene molecule, at β-vinyl and ortho-aryl positions, to give an iridium(III) metalloindene intermediate; this intermediate then adds a β-vinyl C-H bond of a second styrene molecule before reductively eliminating product. Several metalloindene complexes have been isolated and crystallographically characterized. In accord with the proposed mechanism, substitution at the ortho-aryl positions of the styrene precludes dehydrogenative homocoupling. In the case of 2,4,6-trimethylstyrene, dehydrogenative coupling of β-vinyl and ortho-methyl C-H bonds affords dimethylindene, demonstrating that the dehydrogenative coupling is not limited to C(sp2)-H bonds.
Oxidative cross-coupling of vinylsilanes in water
Cicco, Stefania R.,Martinelli, Carmela,Pinto, Vita,Naso, Francesco,Farinola, Gianluca M.
, p. 15 - 20 (2013/06/27)
Palladium-promoted cross-dimerization reaction of alkenylsilanes is reported for the first time, which is also one of the very first studies on oxidative cross-coupling between vinylic organometallic reagents. The reaction occurs at room temperature in aqueous micelles and represents a convenient access to all-trans push-pull butadienes.
Selective dimerization of aryl-substituted terminal alkynes on bis(indenyl)zirconocene derivatives
Ren, Shenyong,Seki, Takashi,Necas, David,Shimizu, Hiroyuki,Nakajima, Kiyohiko,Kanno, Ken-Ichiro,Song, Zhiying,Takahashi, Tamotsu
supporting information, p. 1443 - 1444 (2013/05/21)
Dimerization of aryl-substituted terminal alkynes on indenyl zirconium complexes occurred in a selective way. 1,4-Aryl-1,3-diene derivatives were formed exclusively after hydrolysis. It is in sharp contrast to the reaction on [Cp2Zr] complexes.
A direct synthesis of symmetrical (E,E)-1,4-diaryl-1,3-butadienes by Wenkert arylation of thiophene
Hintermann, Lukas,Schmitz, Marco,Chen, Yun
supporting information; experimental part, p. 2411 - 2415 (2010/12/25)
The nickel-catalyzed coupling of thiophene with aryl Grignard reagents (Wenkert reaction) is accelerated by N-heterocyclic carbene or trialkylphosphane ligands, providing a general, scalable direct synthesis of symmetrical 1,4-diarylbutadienes.
Palladium-catalyzed oxidative homocoupling of potassium alkenyltrifluoroborates: synthesis of symmetrical 1,3-dienes
Weber, Minéia,Singh, Fateh V.,Vieira, Adriano S.,Stefani, Hélio A.,Paix?o, Marcio W.
experimental part, p. 4324 - 4327 (2009/10/26)
Herein, we describe a convenient method for the synthesis of symmetrical 1,3-dienes employing an oxidative palladium-catalyzed homocoupling of potassium alkenyltrifluoroborates providing products in good yields relative to existing methodologies. This is the first report of a cross-dimerization of potassium alkenyltrifluoroborates.
Regioselective heck vinylation of electron-rich olefins with vinyl halides: Is the neutral pathway in operation?
McConville, Matthew,Saidi, Ourida,Blacker, John,Xiao, Jianliang
supporting information; experimental part, p. 2692 - 2698 (2009/08/15)
Highly regioselective vinylation of electron-rich olefins by bromo- as well as chlorostyrenes is effected by palladium catalysis with either mono- or bidentate phosphines in a molecular solvent, with no need for halide scavengers, ionic liquids, or ionic additives. The use of the hemilabile 1,3-bis(diphenylphosphino)propane monoxide (dpppO) as a ligand led to faster reactions of more challenging 2-substituted vinyl ethers and reduced Pd loadings. In contrast to the related arylation reaction, evidence suggests that the vinylation may proceed via the neutral Heck mechanism.
Homocoupling of arylboronic acids with a catalyst system consisting of a palladium(II) N-heterocyclic carbene complex and p-benzoquinone
Yamamoto, Yoshihiko
, p. 1913 - 1916 (2008/03/13)
In the presence of 1-3 mol% SIPr-ligated Pd(OAc)2 and 0.6 equivalent of p-benzoquinone, various arylboronic acids underwent homocoupling in MeOH at ambient temperature to produce symmetrical biaryls in 38-96% yields. Georg Thieme Verlag Stuttgart.
Sequential cross-coupling of 1,4-bissilylbutadienes: Synthesis of unsymmetrical 1,4-disubstituted 1,3-butadienes
Denmark, Scott E.,Tymonko, Steven A.
, p. 8004 - 8005 (2007/10/03)
A mild and general and stereospecific cross-coupling reaction of unsymmetrical 1,4-bissilyl-1,3-butadienes has been accomplished. By the use of either a benzyldimethylsilyl or 2-thienyldimethylsilyl unit at one end of the dienylsilanol, a selective cross-
