17679-93-5Relevant articles and documents
Acetylenic silyl ketone as polysynthetic equivalent of useful building blocks in organic synthesis
Capperucci, Antonella,Degl'Innocenti, Alessandro,Dondoli, Paolo,Nocentini, Tiziano,Reginato, Gianna,Ricci, Alfredo
, p. 6267 - 6276 (2007/10/03)
Ethynyl silyl ketone 1 proved to be a very efficient Michael acceptor in carbocupration and metallocupration reactions. In particular, when using carbocuprates, a smooth entry to polyenals can be obtained, while, when using metallocuprates, silyl- and stannylpropenoyl silanes may be obtained, very powerful intermediates in organic synthesis.
Newly designed acylsilanes as versatile tools in organic synthesis
Bonini, Bianca F.,Comes-Franchini, Mauro,Fochi, Mariafrancesca,Mazzanti, Germana,Ricci, Alfredo
, p. 181 - 189 (2007/10/03)
Structural variations in acylsilane molecules allow a number of new selective synthetic processes to be performed which lead to sulfur-containing heterocycles, highly functionalized and unsaturated polycarbonyl derivatives, polyenes, and β- and γ-aminoalcohols. The synthesis of these compounds, most of them not easily accessible through conventional routes, takes advantage of the site-selective reactions occurring at the C-Si bonds, of the increased stability of acylsilanes with respect to that of the corresponding aldehydes and of the high diastereofacial selectivity introduced by the SiR3 group. Herein we report the different synthetic strategies leading to the synthesis of several functionalized acylsilanes and their synthetic applications. The use of new selective polymetallic reagents for the nucleophilic silylation will be presented as well.
Complexations of 1,4-Dienes to Rhodium(I) Pentane-2,4-dionates; Thermal Rearrangements of the Complexes
Aneja, Rajindra,Golding, Bernard T.,Pierpoint, Colin
, p. 219 - 224 (2007/10/02)
As models for natural products containing a 'skipped' diene fragment (-CH=CHCH2CH=CH-), a series of hepta-2,5-dienes, hepta-2,5-dien-4-ols, and hepta-2,5-dien-4-ol acetates have been prepared.Some of these dienes react with either bis(ethylene)(pentane-2,4-dionato)rhodium(I) or bis(ethylene)(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)rhodium(I) to afford 1:1 complexes, e.g. (1,1,1,5,5,5-hexafluoropentane-2,4-dionato)rhodium(I).Other dienes, e.g. (Z,Z)-hepta-2,5-diene, form 2:1 complexes in which for each molecule of diene, one double bond is co-ordinated to rhodium, whereas the other is not.The (Z,Z)-dienes do not form 1:1 complexes because there would be a severe steric interaction between the terminal substituents of each double bond in such complexes.For the complexes of the dienols and certain allylic alcohols (e.g. prop-2-en-1-ol), evidence was obtained for the presence of a stabilizing intramolecular hydrogen bond between each OH and its nearest CO of the pentane-2,4-dionate.When heated in benzene with 5 mol percent of bis(ethylene)-(pentane-2,4-dionato)rhodium(I) each dienol rearranged to give an enone as the main product .Their acetates rearranged to isomeric conjugated dienes .The hepta-2,5-dienes were recovered unchanged.The mechanism of the rearrangements observed are explained in terms of intermediate (?-allyl)rhodium complexes.
Compounds formed by combining transition metal halides or oxyhalides, or aluminum chloride, with alkaline earth metal halides
-
, (2008/06/13)
Novel salt-like compounds adapted to be used as component of catalytic systems in the polymerization of ethylenically unsaturated monomers are disclosed: these compounds are obtained by reacting halides of transition metals or of aluminium with halides of alkaline earth metals, in the presence of phosphorous oxide derivatives which have the function of solvating agents. Also oxyhalides of transition metals lie within the scope of the invention.
