53395-25-8Relevant academic research and scientific papers
Heterogeneous gold(I)-catalyzed three-component reaction of aldehydes, alkynes, and orthoformates toward propargyl ethers
Zeng, Jiajun,Yi, Feiyan,Cai, Mingzhong
supporting information, p. 1936 - 1945 (2020/06/01)
A novel and efficient heterogeneous gold(I)-catalyzed three-component reaction of aldehydes, alkynes, and orthoformates has been developed that proceeds smoothly in dichloroethane (DCE) at 83 °C in the presence of 5 mol% magnetic nanoparticles-anchored phosphine gold(I) complex (Fe3O4@SiO2-P-AuOTf) and offers a general and practical approach for the preparation of a variety of propargyl ethers with good yields. This heterogeneous gold(I) catalyst can be facilely recovered by simply applying an external magnetic field and recycled at least eight times without any apparent decrease in the catalytic efficiency.
Synthesis of propargylic ethers by gold-mediated reaction of terminal alkynes with acetals
Furuta, Miyu,Sugiyama, Kyoko,Yamaguchi, Minami,Ueda, Hirofumi,Tokuyama, Hidetoshi
, p. 872 - 876 (2019/08/20)
A gold-catalyzed introduction of various terminal alkynes to acetals was investigated. Extensive optimization of the reaction conditions revealed that thermally stable cationic gold catalysts bearing bulky ligands such as 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene 3-1H-benzo[d][1,2,3]triazolyl gold trifluoromethanesulfonate (IPrAu(BTZ-H)OTf) were particularly suitable for the reaction. Additionally, significant solvent effects were observed. Ether solvents such as tetrahydrofuran (THF), cyclo pentyl methyl ether (CPME), and 1,4-dioxane were effective for the reaction. Studies on the scope of substrates and alkynes indicated that various alkynes and acetals were feasible to provide a wide range of propargylic ethers.
Catalytic Alkynylation of Cyclic Acetals and Ketals Enabled by Synergistic Gold(I)/Trimethylsilyl Catalysis
Berthet, Mathéo,Songis, Olivier,Taillier, Catherine,Dalla, Vincent
, p. 9916 - 9922 (2017/09/23)
A completely regioselective and challenging gold(I)-catalyzed ring-opening of cyclic 1,3-dioxolanes and dioxanes by trimethylsilyl alkynes to set diol-derived propargyl trimethylsilyl bis-ethers is reported. This unprecedented and not trivial transformation does not operate with the catalytic methodologies recently reported for catalytic alkynylation of acyclic acetals/ketals, and is uniquely enabled by the application of a recently introduced synergistic gold(I)-silicon catalysis concept capable of producing simultaneously catalytic amounts of two key players, a silicon-based Lewis superacid and a nucleophilic gold acetylide.
TRACELESS DIRECTING GROUPS IN RADICAL CASCADES: FROM OLIGOALKYNES TO FUSED HELICENES WITHOUT TETHERED INITATORS
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Paragraph 0279-0281, (2016/06/13)
The present disclosure is directed to a traceless directing group in a radical cascade. The chemo- and regioselectivity of the initial attack in skipped oligoalkynes is controlled by a propargyl alkoxy moiety. Radical translocations lead to the boomerang return of radical center to the site of initial attack where it assists to the elimination of the directing functionality via β-scission in the last step of the cascade. In some aspects, the reaction of the present invention is catalyzed by a stannane moiety, which allows further via facile reactions with electrophiles as well as Stille and Suzuki cross-coupling reactions. This selective radical transformation opens a new approach for the controlled transformation of skipped oligoalkynes into polycyclic ribbons of tunable dimensions.
Traceless directing groups in radical cascades: From oligoalkynes to fused helicenes without tethered initiators
Pati, Kamalkishore,Gomes, Gabriel Dos Passos,Harris, Trevor,Hughes, Audrey,Phan, Hoa,Banerjee, Tanmay,Hanson, Kenneth,Alabugin, Igor V.
supporting information, p. 1165 - 1180 (2015/02/05)
We report the first example of a traceless directing group in a radical cascade. The chemo- and regioselectivity of the initial attack in skipped oligoalkynes is controlled by propargyl OR moiety. Radical translocations lead to the boomerang return of the radical center to the site of initial attack where it assists the elimination of the directing functionality via β-scission in the last step of the cascade. The Bu3Sn moiety continues further via facile reactions with electrophiles as well as Stille and Suzuki cross-coupling reactions. This selective radical transformation opens a new approach for the controlled transformation of skipped oligoalkynes into polycyclic ribbons of tunable dimensions. (Chemical Equation Presented).
A General Access to Propargylic Ethers through Br?nsted Acid Catalyzed Alkynylation of Acetals and Ketals with Trifluoroborates
Baxter, Matthew,Bolshan, Yuri
, p. 13535 - 13538 (2015/09/22)
A general Br?nsted acid catalyzed methodology for the alkynylation of acetals and ketals with alkynyltrifluoroborate salts has been developed. The reaction proceeds rapidly to afford valuable synthetic building block propargylic ethers in good to excellent yields. Unlike Lewis acid catalyzed transformations of trifluoroborates, this approach does not proceed via unstable organodifluoroborane intermediate. As a result, the developed methodology features excellent functional group tolerance and good atom economy. Br?nsted acid catalyzed alkynylation of acetals and ketals is described. Alkynyltrifluoroborate salts react rapidly to afford propargylic ethers. Organodifluoroborane, which is a common intermediate in Lewis acid catalyzed reactions of trifluoroborates, has not been observed. The reaction exhibits generally high yields and excellent functional group tolerance.
Silver hexafluoroantimonate-catalyzed direct α-alkylation of unactivated ketones
Naveen, Naganaboina,Koppolu, Srinivasa Rao,Balamurugan, Rengarajan
, p. 1463 - 1473 (2015/05/26)
A practically simple and direct α-alkylation of unactivated ketones using benzylic alcohols has been achieved. The in situ formed acetals are the key for the success of the reaction. The catalyst, silver hexafluoroantimonate(V) (AgSbF6) provide
Gold(I)-catalyzed decarboxylation of propargyl carbonates: Reactivity reversal of the gold catalyst from π-Lewis acidity to σ-Lewis acidity
Shen, Ruwei,Yang, Jianjun,Zhu, Shugao,Chen, Chao,Wu, Luling
, p. 1259 - 1269 (2015/04/22)
A cationic gold(I)-catalyzed decarboxylative etherification of propargyl carbonates to selectively produce propargyl ethers is reported. In the reaction the gold(I) catalyst shows a distinct σ-Lewis acidity rather than the commonly observed π-Lewis acidity, and thus catalyzes the decarboxylation of a variety of propargyl carbonates to give the corresponding propargyl ethers with high selectivity. This reaction represents a rare example of the tunable reactivity of cationic gold(I) complexes between σ-Lewis acidity and π-Lewis acidity.
Enantioselective copper-catalyzed alkynylation of benzopyranyl oxocarbenium ions
Srinivas, Harathi D.,Maity, Prantik,Yap, Glenn P. A.,Watson, Mary P.
, p. 4003 - 4016 (2015/09/07)
We have developed highly enantioselective, copper-catalyzed alkynylations of benzopyranyl acetals. By using a copper(I) catalyst equipped with a chiral bis(oxazoline) ligand, high yields and enantioselectivities are achieved in the alkynylation of widely
Nucleophilic substitution of propargyl alcohols with aliphatic alcohols, aliphatic amines and heterocycles catalyzed by 4-nitrobenzenesulfonic acid: A scalable and metal-free process
Antony Savarimuthu,Leo Prakash,Augustine Thomas
supporting information, p. 3213 - 3217 (2014/06/09)
It is aimed to provide a cost effective p-NBSA catalyzed nucleophilic substitution of propargyl alcohols with alcohols, amines and heterocycles, without employing corrosive and costly metal catalysts, toxic solvents and column chromatography for purification. A systematic study of CC, CN and CO bond formation and efficacy of the scalability have also been confirmed.
