202391-28-4Relevant 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.
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.
Stereo- and regioselective palladium-catalysed hydroarylation and hydrovinylation of functionalised alkynes: A route to substituted Z-2-cinnamyl esters, 3-chromen-2-ols, and coumarins
Cacchi, Sandro,Fabrizi, Giancarlo,Moro, Leonardo,Pace, Paola
, p. 1367 - 1370 (2007/10/03)
The palladium-catalysed hydroarylation and hydrovinylation of methyl 3-phenylpropynoate and 3,3-diethoxy-1-(o-tetrahydropyranyloxy)phenyl-1-propyne with aryl and vinyl halides or inflates in the presence of Pd(OAc)2 and KOOCH has been studied. The reaction affords stereoselectively syn addition products. The regiochemical outcome appears to be controlled by steric effects and the new carbon-carbon bond is generated preferentially on the carbon far from the aromatic ring ligated to the acetylenic carbon. The reaction can be applied to the synthesis of 3-substituted-3-chromen-2-ols and 3-substituted coumarins.
