Regioselective Formation of Enol Esters from the Ruthenium-Catalyzed Markovnikov Addition of Carboxylic Acids to Alkynes
作者:Janine Jeschke、Christian Gäbler、Heinrich Lang
DOI:10.1021/acs.joc.5b02293
日期:2016.1.15
selectivities with up to 99% of the Markovnikov product were achieved. The electronic influence of the substrates on the reaction rate was quantified by Hammett plots. By the use of electron-rich alkynes or highly acidic carboxylic acids, the reaction rate could be increased. Hence, the addition of highly acidic pentafluorobenzoic acid to electron-rich 4-methoxyphenylacetylene can even be carried out
The crossed aldol reaction of enol esters, which are weak carbon nucleophiles, with aldehydes was effectively carried out under mild conditions by using a catalytic amount of several cationic species paired with tetrakis(pentafluorophenyl)borate.
Control over C–O and C–C bond formation: ruthenium catalyzed regiospecific addition of carboxylic acid to alkyne and stereoselective dimerization of alkyne
作者:Jyotsna Tripathy、Manish Bhattacharjee
DOI:10.1016/j.tetlet.2009.06.039
日期:2009.8
A cationic ruthenium(II) complex, [Ru(PPh3)2(CH3CN)3Cl][BPh4] (1), has been found to be an effective catalyst for stereoselective dimerization of alkynes in the presence of a base, and for regiospecificaddition of carboxylic acids to alkynes in presence of the Lewis acid, BF3·Et2O.
Benzoic Acid Ester Compounds, Compositions, Uses and Methods Related Thereto
申请人:Miralles Ricardo
公开号:US20080206158A1
公开(公告)日:2008-08-28
Benzoic acid ester compounds of formula (I):
wherein R and R
1
-R
5
have the meanings explained in the description, methods for producing them and use thereof in cosmetic, pharmaceutical, personal care and industrial preparations as sunscreens based on photochemical precursor properties of ultraviolet absorbers.
Ligand and Substrate Effects on Regio‐ and Stereoselective Ru(II)‐Catalyzed Hydroacyloxylations to Vinylic Esters
作者:Paul A. Beasley、Frank E. McDonald
DOI:10.1002/adsc.202301222
日期:2024.2.20
Two Ru(II)-catalytic systems were developed for anti-Markovnikov regioselective hydroacyloxylations of terminal alkynes to vinylic esters. [Ru(NCCH3)6][(BF4)2] favors (E)-vinylic ester products with arylacetylenes and select carboxylic acids, whereas a Ru scorpionate complex with two electron-withdrawing ligands favors (Z)-vinylic ester isomers.