89374-88-9Relevant academic research and scientific papers
ALKENYL-COPPER DERIVATIVES 24 STEREOSPECIFIC SYNTHESIS OF ENONES BY PALLADIUM CATALYSED ACYLATION OF ALKENYL-COPPER REAGENTS
Jabri, N.,Alexakis, A.,Normant, J. F.
, p. 5081 - 5084 (1983)
α,β-ethylenic ketones and α,α',β,β'diethylenic ketones with a stereodefined substitution pattern are easily prepared by coupling of alkenyl copper and cuprate reagents, directly obtained by carbocupration of alkynes, with acid chlorides and anhydrides in the presence of a catalytic amount of Pd(0) complex.
Mechanism of Mukaiyama-Michael reaction of ketene silyl acetal: Electron transfer or nucleophilic addition?
Otera, Junzo,Fujita, Yukihiro,Sakuta, Nobuyuki,Fujita, Morifumi,Fukuzumi, Shunichi
, p. 2951 - 2962 (2007/10/03)
Mechanism of Mukaiyama-Michael reaction of ketene silyl acetal has been discussed. The competition reaction employing various types of ketene silyl acetals reveals that those bearing more substituents at the β-position react preferentially over less substituted ones. However, when ketene silyl acetals involve bulky siloxy and/or alkoxy group(s), less substituted compounds react preferentially. The Lewis acids play an important role in these reactions. Enhanced preference for the more sterically demanding Michael adducts is obtained with Bu2Sn(OTf)2, SnCl4, and Et3-SiClO4 in the former reaction while TiCl4 gives the highest selectivity for the less sterically demanding products in the latter case. These results are interpreted in terms of alternative reaction mechanisms. The reaction of less bulky ketene silyl acetals are initiated by electron transfer from these compounds to a Lewis acid. On the other hand, bulkier ketene silyl acetals undergo a ubiquitous nucleophilic reaction. Such a mechanistic change is discussed based on a variety of experimental results as well as the semiempirical PM3 MO calculations.
SOME ASPECTS OF THE REACTIONS OF SILYL ENOL ETHERS WITH 1,3-DIOXACYCLOALKANES
Amerkhanov, R. R.,Gal'chenko, E. P.,Musavirov, R. S.,Rakhmankulov, D. L.
, p. 468 - 470 (2007/10/02)
1,3-Dioxacycloalkanes react with silyl enol ethers like linear acetals. The yield of the unsaturated ketone is influenced by the type and size of the substituent in the second position of the ring. Formals do not undergo the above-mentioned reaction.
PALLADIUM MEDIATED SYNTHESIS OF CONJUGATED E or Z ENONES AND UNSYMMETRICAL DIVINYL KETONES. ONE-POT PREPARATION OF ISOEGOMAKETONE
Jabri, N.,Alexakis, A.,Normant, J. F.
, p. 1369 - 1380 (2007/10/02)
The palladium (o) catalyzed coupling of acyl halides or anhydrides with alkenyl copper reagents furnishes α,β ethylenic ketones and α,β-α',β' diethylenic ketones in high yield.The substitution pattern of the alkenyl copper reagent, directly obtained by carbocupration of alkynes, is fully retained.Anhydrides of Z-ethylenic acids also retain their Z stereochemistry. β-halogeno-vinyl ketones react under the above conditions to afford α,β-γ,δ dienones.An efficient one-pot synthesis of Z or E isoegomaketone is reported.
