125345-29-1Relevant academic research and scientific papers
On the trapping of vinylgold intermediates
Hashmi, A. Stephen K.,Ramamurthi, Tanuja Dondeti,Rominger, Frank
, p. 971 - 975 (2010)
An internal aryl-substituted ortho-alkynylphenol and a similar aniline with stoichiometric amounts of N,N'-bis(2,6-diisopropylphenyl)imidazol-2-ylidene- gold tosylate [(IPr)AuOTs] and triethylamine gave the aurated heterocycles as stable intermediates of
Copper-catalyzed (4+1) and (3+2) cyclizations of iodonium ylides with alkynes
Liang, Hao,He, Xiaobo,Zhang, Yaqi,Chen, Bin,Ouyang, Jia-Sheng,Li, Yongsu,Pan, Bendu,Subba Reddy, Chitreddy V.,Chan, Wesley Ting Kwok,Qiu, Liqin
supporting information, p. 11429 - 11432 (2020/10/12)
The copper(ii)-catalyzed (4+1) cyclizations and copper(i)-catalyzed (3+2) cycloadditions of iodonium ylides and alkynes were successfully developed by employing efficient and safe iodonium ylides instead of traditional diazo compounds. Highly functionaliz
Enantioselective intramolecular cyclization of alkynyl esters catalyzed by a chiral Br?nsted base
Kondoh, Azusa,Tran, Hoa Thi Quynh,Kimura, Kyoko,Terada, Masahiro
supporting information, p. 5726 - 5729 (2016/05/19)
An enantioselective intramolecular cyclization reaction of alkynyl esters was developed, which employs a Br?nsted base catalyst generated in situ from a chiral Schiff base and t-BuOK. This reaction is a rare example of the enantioselective intramolecular addition of simple ester enolates to alkynes under Br?nsted base catalysis.
Dual Photoredox/Gold Catalysis Arylative Cyclization of o-Alkynylphenols with Aryldiazonium Salts: A Flexible Synthesis of Benzofurans
Xia, Zhonghua,Khaled, Omar,Mouriès-Mansuy, Virginie,Ollivier, Cyril,Fensterbank, Louis
, p. 7182 - 7190 (2016/08/30)
A new method for the arylative cyclization of o-alkynylphenols with aryldiazonium salts via dual photoredox/gold catalysis is described. The reaction proceeds smoothly at room temperature in the absence of base and/or additives and offers an efficient app
Gold-Catalyzed Domino Synthesis of Functionalized Benzofurans and Tetracyclic Isochromans via Formal Carboalkoxylation
Obata, Tomoyuki,Suzuki, Sho,Nakagawa, Asuka,Kajihara, Ryota,Noguchi, Keiichi,Saito, Akio
supporting information, p. 4136 - 4139 (2016/08/30)
A domino synthesis of benzofurans with the modification of side chains from α-alkoxyalkyl o-alkynylaryl ethers (n = 0) and electron-rich arenes has been developed. In the present domino reaction, which would proceed via the α-alkoxyalkylation of arenes with an intermediate in the migratory cycloisomerization of o-alkynylaryl ethers followed by the nucleophilic addition of benzofurans to benzyl ethers, a cationic Au(III) catalyst activates the C-C π bond and the C-O σ bond. The present method could be extended to Au(I)-catalyzed domino synthesis of tetracyclic isochromans from α-alkoxyalkyl (o-alkynylaryl)methyl ethers (n = 1) and aryl methoxymethyl ethers.
Highly efficient heterogeneous synthesis of benzofurans under aqueous condition
Sun, Shi-Xin,Wang, Jun-Jie,Xu, Zi-Jun,Cao, Lu-Ya,Shi, Zi-Fa,Zhang, Hao-Li
supporting information, p. 3798 - 3806 (2014/05/20)
Highly efficient organic reactions in water are important for designing environmental-friendly and low cost synthetic processes. Herein, we demonstrate an intermediate-in-water strategy for the heterogeneous synthesis of benzofurans in aqueous media. The cyclization reaction of 2-(phenylethynyl)phenol to 2-phenylbenzofuran cannot proceed in pure water. However, this reaction can be efficiently promoted by the formation of sparingly soluble intermediate in the presence of alkaline. Quantitative conversion of a variety of substrates to benzofuran derivatives has been achieved in the absence of noble metal catalyst. Other remarkable features including easy-isolation and purification of product, along with wide range of functional group tolerance render the methodology promising in the realm of green-synthesis.
Rhodium-catalyzed olefin isomerization/enantioselective intramolecular alder-ene reaction cascade
Okamoto, Ryuichi,Okazaki, Eri,Noguchi, Keiichi,Tanaka, Ken
supporting information; experimental part, p. 4894 - 4897 (2011/11/29)
The olefin isomerization/enantioselective intramolecular Alder-ene reaction cascade was achieved by using a cationic rhodium(I)/(R)-BINAP complex as a catalyst. A variety of substituted dihydrobenzofurans and dihydronaphthofurans were obtained from phenol
Iodocyclization of ethoxyethyl ethers to alkynes: A broadly applicable synthesis of 3-iodobenzo[b]furans
Okitsu, Takashi,Nakazawa, Daisuke,Taniguchi, Rie,Wada, Akimori
supporting information; experimental part, p. 4967 - 4970 (2009/05/31)
(Chemical Equation Presented) A wide variety of 3-iodobenzo[b]furans were readily prepared by iodocyclization of 2-alkynyl-1-(1-ethoxyethoxy)benzenes with the I(coll)2PF6-BF3-OEt2 combination. Aryl-, vinyiic-, a
Synthesis of 2,3-disubstituted benzofurans and indoles by π-Lewis acidic transition metal-catalyzed cyclization of ortho-alkynylphenyl O,O- and N,O-acetals
Nakamura, Itaru,Mizushima, Yuya,Yamagishi, Uichiro,Yamamoto, Yoshinori
, p. 8670 - 8676 (2008/02/08)
The PtCl2-catalyzed cyclization reaction of ortho-alkynylphenyl acetals 1 in the presence of COD (1,5-cyclooctadiene) produces 3-(α-alkoxyalkyl)benzofurans 2 in good to high yields. For example, the reaction of acetaldehyde ethyl 2-(1-octynyl)phenyl acetal (1a), acetaldehyde ethyl 2-(cyclohexylethynyl)phenyl acetal (1c), and acetaldehyde ethyl 2-(phenylethynyl)phenyl acetal (1f) in the presence of 2 mol % of platinum(II) chloride and 8 mol % of 1,5-cycloocatadiene in toluene at 30 °C gave the corresponding 2,3-disubstituted benzofurans 2a, 2c, and 2f in 91, 94, and 88% yields, respectively. Moreover, the reaction of N-methoxymethyl-2-alkynylanilines 3 was catalyzed by PdBr2, affording the corresponding 2,3-disubstituted indoles 4 in moderate yields. For example, the reaction of N-methoxymethyl-2-(1-pentynyl)-N-tosylaniline (3a) and N-methoxymethyl-2-(phenylethynyl)-N-tosylaniline (3b) in the presence of 10 mol % of PdBr2 in toluene at 80 °C gave 3-methoxymethyl-2-propyl-1-tosylindole (4a) and 3-methoxymethyl-2-phenyl-1-tosylindole (4b) in 33 and 33% yields, respectively.
Heterocycles by PtCl2-catalyzed intramolecular carboalkoxylation or carboamination of alkynes
Fuerstner, Alois,Davies, Paul W.
, p. 15024 - 15025 (2007/10/03)
PtCl2 constitutes a convenient catalyst for intramolecular hydroalkoxylation, carboalkoxylation, hydroamination, and carboamination reactions of alkynes, effecting the formation of substituted benzo[b]furan, indole-, and isochromene-1-one derivatives, respectively. This procedure allows for the transfer of (substituted) allyl, methoxymethyl (MOM), benzyloxymethyl (BOM), and (trimethylsilyl)ethoxymethyl (SEM) groups from oxygen to carbon and is compatible with functional groups that are susceptible to oxidative insertion of low valent metal species previously used for similar purposes. Although some of the reactions can even be carried out in air, the rates are significantly increased when conducted under an atmosphere of CO. A mechanistic rationale is proposed, implying activation of the alkyne by the carbophilic Pt(2+) template as the primary step of the catalytic cycle. Copyright
