- The Scope and Limitations of Intramolecular Radical Cyclizations of Acylsilanes with Alkyl, Aryl, and Vinyl Radicals
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5-Exo cyclizations of primary and secondary radicals with acylsilanes successfully give cyclopentyl silyl ethers. The corresponding 6-exo cyclizations are sensitive to changes of the size of silyl groups. Secondary radicals undergo 6-exo cyclizations with
- Chang, Sheng-Yueh,Jiaang, Weir-Torn,Cherng, Chaur-Donp,Tang, Kuo-Hsiang,Huang, Chih-Hao,Tsai, Yeun-Min
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p. 9089 - 9098
(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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- Regioselectivity in and Annulation Reactions of Bis(trimethylsilyl) Enol Ethers with Acylsilane Dicarbonyl Dielectrophiles
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A number of 1,4- and 1,5-acylsilane dicarbonyl compounds were synthesized using Corey-Brook dithiane methods.These dicarbonyl substrates were annulated with the bis(trimethylsilyl) enol ether of methyl acetoacetate in the presence of TMSOTf, affording bic
- Molander, Gary A.,Siedem, Christopher S.
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p. 130 - 138
(2007/10/02)
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