62358-88-7Relevant academic research and scientific papers
Rhodium-Catalyzed 1,1-Hydroacylation of Thioacyl Carbenes with Alkynyl Aldehydes and Subsequent Cyclization
Zhou, Bingnan,Wu, Qiuyue,Dong, Ziyang,Xu, Jiaxi,Yang, Zhanhui
supporting information, p. 3594 - 3599 (2019/05/24)
A rhodium-catalyzed 1,1-hydroacylation of thioacyl carbenes with alkynyl and alkenyl aldehydes and subsequent 6-endo-trig/dig cyclization are realized, giving structurally diverse 4H-thiopyran-4-ones and 2,3-dihydro-4H-thiopyran-4-ones in moderate to good yields. The oxidative addition of Rh(I) to aldehydes is proposed to be the turnover-limiting step. Manipulations of estrones demonstrate the applications of our formal (3 + 3) transannulations in the structural modifications of natural products.
Blue light photoredox-catalysed acetalation of alkynyl bromides
Lyu, Xue-Li,Huang, Shi-Sheng,Song, Hong-Jian,Liu, Yu-Xiu,Wang, Qing-Min
, p. 36213 - 36216 (2019/11/20)
Herein, we report an organo-photoredox-based protocol using 2,2-diethoxyacetic acid as the acetal source to achieve acetalation of alkynyl bromides to afford various alkynyl acetal products. In addition to arylethynyl bromides, substrates bearing heteroaryl rings (thiophene, pyridine, and indole) smoothly gave the corresponding acetalation products. This mild protocol has potential utility for the synthesis of aldehydes by further protonization.
CsF-Mediated in Situ Desilylation of TMS-Alkynes for Sonogashira Reaction
Capani, Joseph S.,Cochran, John E.,Liang, Jianglin
, p. 9378 - 9384 (2019/07/08)
A practical and mild set of conditions for the Sonogashira reaction utilizing CsF-mediated in situ TMS-alkyne desilylation followed by Sonogashira coupling has been developed for the synthesis of a variety of alkynyl benzenes and heteroarenes in good to excellent yields. This methodology demonstrates excellent functional group tolerance and simple purification, which allows large-scale industrial applications. This one-pot protocol enables a high-yielding Sonogashira coupling with volatile alkynes by avoiding challenging isolation of free alkynes.
Consecutive three-component synthesis of 3-(hetero)aryl-1H-pyrazoles with propynal diethylacetal as a three-carbon building block
Levi, Lucilla,Boersch, Christina,Gers, Charlotte F.,Merkul, Eugen,Mueller, Thomas J. J.
experimental part, p. 9340 - 9356 (2012/01/04)
A novel consecutive three-component synthesis of 3-(hetero)aryl-1H- pyrazoles via room temperature Sonogashira arylation of propynal diethylacetal used as a propargyl aldehyde synthetic equivalent has been disclosed. The final acetal cleavage-cyclocondensation with hydrazine hydrochloride at 80 °C rapidly furnishes the title compounds in a one-pot fashion.
Sonogashira reaction of aryl halides with propiolaldehyde diethyl acetal catalyzed by a tetraphosphine/palladium complex
Lemhadri, Mhamed,Doucet, Henri,Santelli, Maurice
, p. 9839 - 9847 (2007/10/03)
All-cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/[PdCl(C 3H5)]2 efficiently catalyzes the Sonogashira reaction of propiolaldehyde diethyl acetal with a variety of aryl bromides and chlorides. A minor electronic effect of the substituents of the aryl bromide was observed. Similar reaction rates were observed in the presence of activated aryl bromides such as 4-trifluoromethylbromobenzene and deactivated aryl bromides such as bromoanisole. Turnover numbers up to 95,000 can be obtained for this reaction. Even aryl chlorides and heteroarylbromides or chlorides have been successfully alkynylated with this catalyst. Moreover, a wide variety of substituents on the aryl halide such as fluoro, trifluoromethyl, acetyl, benzoyl, formyl, nitro, dimethylamino or nitrile are tolerated.
