- Stereoselective addition of organomanganese reagents to chiral acylsilanes and aldehydes
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Organomanganese halides and organomanganates prepared by transmetalation of organolithium and Grignard reagents add smoothly to the carbonyl moiety of acylsilanes and of substituted aldehydes bearing a chiral center at the α-position affording the desired
- Boucley, Céline,Cahiez, Gérard,Carini, Silvia,Cerè, Vanda,Comes-Franchini, Mauro,Knochel, Paul,Pollicino, Salvatore,Ricci, Alfredo
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- Allylation reactions of acylsilanes as synthetic equivalents of aldehydes. Application of a stereocontrolled synthesis of (1S,2S,5S)-(10S)- and-(10R)-allyl myrtanol
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The allylation of acylsilanes with tetraallyltin in the presence of catalytic amounts of Sc(OTf)3 proceeded smoothly to afford the silylated homoallylic alcohols in good yields. Subsequent protiodesilylation gave the formal adducts of the corre
- Bonini, Bianca Flavia,Comes-Franchini, Mauro,Fochi, Mariafrancesca,Mazzanti, Germana,Nanni, Cristiano,Ricci, Alfredo
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p. 6737 - 6740
(2007/10/03)
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- Reductions, reductive alkylations, and intramolecular cyclizations of acyl silanes with samarium diiodide or tributyltin hydride
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A series of acyl silanes including aliphatic-, aromatic-, and bis-acyl silanes, as well as the acyl silanes bearing other substituents such as a bromine atom and alkenyl, succinimide, and carbonyl groups, were prepared, and their reactions with samarium diiodide or tributylstannane were studied. The reactions of acyl silanes occurred in various manners such as reductions, reductive alkylations, intramolecular radical cyclizations, pinacol couplings, aldol reactions, and Tishchenko reactions, depending on the nature of substrates and reaction conditions. Acyl silanes were generally reduced to give the corresponding α-silyl alcohols without transfer of silyl groups. Intramolecular radical cyclizations of 5-hexenoyl silanes and 1-silyl-1,5-pentanedione were realized to give α-silyl cyclopentanols and 1,2-cyclopentanediol derivatives, respectively. On treatment with samarium diiodide in tetrahydrofuran, 1-(trimethylsilyl)-1,6-hexanedione underwent a pinacol coupling reaction in the presence of t-BuOH, whereas it underwent a Tishchenko reaction in the presence of MeOH. The Tishchenko reaction of 1-silyl-1,5-pentanedione gave a δ-silyl-δ-lactone. On treating with samarium diiodide, 1-(trimethylsilyl)-1,5-hexanedione and 1,5-bis(trimethylsilyl)-1,6-hexanedione, underwent, respectively, intramolecular aldol reactions.
- Chuang, Tsung-Hsun,Fang, Jim-Min,Jiaang, Weir-Torn,Tsai, Yeun-Min
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p. 1794 - 1805
(2007/10/03)
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