- Flexible stereoselective functionalizations of ketones through umpolung with hypervalent iodine reagents
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The functionalization of carbonyl compounds in the α-position has gathered much attention as a synthetic route because of the wide biological importance of such products. Through polarity reversal, or "umpolung", we show here that typical nucleophiles, such as oxygen, nitrogen, and even carbon nucleophiles, can be used for addition reactions after tethering them to enol ethers. Our findings allow novel retrosynthetic planning and rapid assembly of structures previously accessible only by multistep sequences. A Nu approach: An efficient α-functionalization of ketones with a range of simple and useful nucleophiles is possible by using hypervalent iodine reagents (see scheme; Nu′ can be the Nu itself or a protected form of this nucleophile group).
- Mizar, Pushpak,Wirth, Thomas
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supporting information
p. 5993 - 5997
(2014/06/10)
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- Preparation of low loss optical material from difunctional silyl enol ethers and difunctional silanols
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Certain compounds within the general formula (I) wherein: Ra and Ra′ are independently alkyl, aryl or aralkyl; Rb and Rb′ are independently CH2, CH-alkyl, CH-aryl or CH-aralkyl; R1 and R2, are independently selected from s
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- Synthesis of silicon-functionalized dimethylsilyl enol ethers from ketones
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Symmetrical dimethylsilyl bis-enol ethers are obtained in good yield by reaction of ketones with dichlorodimethylsilane in the presence of triethylamine and sodium iodide. Reaction of ketones with N,N-diethylaminodimethylchlorosilane in the presence of tr
- Rathke,Weipert
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p. 1337 - 1351
(2007/10/02)
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- PREPARATION OF DIMETHYLSILYL BIS-ENOL ETHERS
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Dichlorodimethylsilane is reacted with two equivalents of ketone enolates to give dimethylsilyl bis-enol ethers in good yields.Lithium tetramethylpiperidide (LiTMP) as well as triethylamine (TEA) are used in deprotonation of ketones.An intramolecular aldo
- Fataftah, Zacharia A.,Ibrahim, Mustafa R.,Abu-Agil, Mahmoud S.
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p. 4067 - 4070
(2007/10/02)
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- O-SILYLATED KETENE ACETAL CHEMISTRY; DIVINYLOXYSILANE DERIVATIVES AS NOVEL AND USEFUL BIFUNCTIONAL PROTECTING AGENTS FOR H-ACIDIC MATERIALS
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Novel reagents, bis(1-methoxy-2-methyl-1-propenyloxy)silanes (2a-d) have been shown to be very useful bifunctional protecting agents for various types of H-acidic materials, such as diols, dithiols, diacids and their combined materials.The reaction proceeds rapidly under mild conditions to give the corresponding silylene derivatives in almost quantitative yields.
- Kita, Yasuyuki,Yasuda, Hitoshi,Sugiyama, Yoshie,Fukata, Fumio,Haruta, Jun-ichi,Yasumitsu, Tamura
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p. 1273 - 1276
(2007/10/02)
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