79090-75-8Relevant academic research and scientific papers
Regio- and Stereochemistry on the Electrophilic Trapping of Allylic Samariums Generated by Reductive Cleavage of Allylic Ethers with (C5Me5)2Sm(thf)n
Takaki, Ken,Kusudo, Takeshi,Uebori, Shinya,Nishiyama, Tetsushi,Kamata, Tohru,Yokoyama, Masaki,Takehira, Katsuomi,Makioka, Yoshikazu,Fujiwara, Yuzo
, p. 4299 - 4304 (2007/10/03)
The C-O bond of allylic benzyl ethers was selectively cleaved with Cp*2Sm(thf)n to give allylic samarium complexes in good yields. Facility of their bond fission has been found to be comparable to that of the corresponding propargylic ethers intermolecularly, but lower intramolecularly. Regio-and stereochemistry on the electrophilic trapping of the allylic complexes thus generated remarkably depended on the nature of the electrophiles. They reacted with carbonyl compounds exclusively from the most substituted terminus of the allylic moieties to yield blanched homoallylic alcohols with anti diasteroselectivity. On the other hand, trapping with silyl chlorides produced linear allylic silanes. Here, a plausible mechanism to account for the difference is proposed.
SYNTHESE D'ALCOHOLS α-ALLENIQUES PAR REACTION D'ORGANOCHROMIQUES PROPARGYLIQUES SUR LES ALDEHYDES ET LES CETONES
Place, Pierre,Verniere, Catherine,Gore, Jacques
, p. 1359 - 1368 (2007/10/02)
Propargylic bromides can be condensed with aldehydes and ketones in the presence of Hiyama's reagent (2CrCl3+LiAlH4 in THF) leading to α-allenic alcohols, to homopropargylic alcohols or to the mixture of both of them.The selectivity (or specificity) of this reaction depends on the substitution of the propargylic bromide, on the structure of the ketone, and on the presence of HMPT in the reaction mixture.In many cases, α- allenic alcohol has been specifically or very selectively obtained.The mechanism of the reaction and the influence of the various parameters are discussed.
