- Palladium-catalyzed coupling reaction of -diazocarbonyl compounds with aromatic boronic acids or halides
-
Efficient palladium-catalyzed cross-coupling reactions of -diazocarbonyl compounds and arylboronic acids or aryl halides have been developed. The reaction proceeds smoothly for a range of diazo compounds, boronic acids, and halides. The coupling reaction conditions tolerate various substituents on the aromatic rings of the substrates, such as chloro, fluoro, acyl, oxo, ester, and nitro groups. This coupling reaction constitutes a novel access to -aryl-substituted ,-unsaturated carbonyl compounds. Mechanistically, palladium-carbene is supposed to be the key intermediate; its formation is followed by migratory insertion of an aryl group to the carbenic carbon of the palladium-carbene complex and subsequent -hydride elimination. Kinetic isotope effect (KIE) data measured for intra- and intermolecular competition experiments suggest that -hydride elimination is not involved in the rate-determining step
- Peng, Cheng,Yan, Guobin,Wang, Yan,Jiang, Yubo,Zhang, Yan,Wang, Jianbo
-
experimental part
p. 4154 - 4168
(2011/02/25)
-
- Palladium-catalyzed cross-coupling of α-diazocarbonyl compounds with arylboronic acids
-
Pd(PPh3)4-catalyzed reaction between α-diazocarbonyl compounds and arylboronic acids leads to the formation of cross-coupling products in good yields. Copyright
- Peng, Cheng,Wang, Yan,Wang, Jianbo
-
p. 1566 - 1567
(2008/09/17)
-
- Photochemical Wittig Reaction of Quasi-phosphonium Ylides
-
α-(Methoxycarbonyl)benzylidene quasi-phosphonium ylides, which are unreactive towards most carbonyl compounds, are found to undergo the Wittig reaction upon irradiation; irradiation with acyclic carbonyl compounds, e.g. benzaldehydes and acetophenones, af
- Tomioka, Hideo,Ichikawa, Naoki,Murata, Hideki
-
p. 193 - 195
(2007/10/02)
-
- SYNTHESIS OF α,β-EPOXY DIAZOMETHYL KETONES
-
The preparation of eighteen epoxy diazomethyl ketones 1 is described.Two general methods were developed.Firstly, treatment of the mixed anhydrides of glycidic acids and carbonic acid ester with diazomethane led to the title compounds in yields ranging from 17-74 percent.Secondly, glycidyl chlorides which were obtained from sodium glycidates and oxalyl chloride, gave the desired products upon treatment with diazomethane ( yields 60-74 percent).The required α,β-epoxy carboxylic esters were prepared by Darzens condensation and epoxidation of α,β-unsaturated esters, but in some cases also by reaction of α-oxo carboxylic esters with diazomethane.
- Thijs, L.,Smeets, F. L. M.,Cillissen, P. J. M.,Harmsen, J.,Zwanenburg, B.
-
p. 2141 - 2144
(2007/10/02)
-