- Carbanions as intermediates in the formation of Grignard reagents
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The formation of reactive carbanions in Grignard reagents was discussed. Inter- and/or intramolecular migrations of organotin and organosilicon groups were also studied. Results showed that the high percentage of rearrangement reactions proves that the anionic species are not located on a minor pathway.
- Van Klink, Gerard P.M.,De Boer, Henricus J.R.,Schat, Gerrit,Akkerman, Otto S.,Bickelhaupt, Friedrich,Spek, Anthony L.
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p. 2119 - 2135
(2008/10/08)
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- Selective lithiation of 1-bromo-2-((trimethylstannyl)methyl)benzene: Synthesis of 1-bromo-2-(lithiomethyl)benzene, 1-lithio-2-((trimethylstannyl)methyl)benzene, and α,2-dilithiotoluene
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Reactions of 1-bromo-2-((trimethylstannyl)methyl)benzene (1) with n-butyllithium and tert-butyllithium have been investigated. With n-butyllithium in tetrahydrofuran (THF) at -70°C, the only observed process was lithium-tin exchange, yielding 1-bromo-2-(lithiomethyl)benzene (2). In contrast, lithium-halogen exchange occurred when 1 was treated with tert-butyllithium in diethyl ether at -80°C to give 1-lithio-2-((trimethylstannyl)methyl)benzene (3). α,2-Dilithiotoluene could be prepared in high yield from 3 and tert-butyllithium in either diethyl ether (room temperature) or THF (-80°C).
- De Boer, Henricus J. R.,Akkerman, Otto S.,Bickelhaupt, Friedrich
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p. 2898 - 2903
(2008/10/08)
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- An Investigation of the Di-Grignard Approach to Metallabenzocyclobutenes of Group 14
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The reactions of 1,2-dihydro-1-magnesabenzocyclobutane (5) with dichlorodimethylsilane (12a), dichloromethylgermane (12b) and dichloromethylstannane (12C) are reported; 1,2-dihydro-1,1-dimethyl-1-silabenzocyclobutene (14a) and 1,2-dihydro-1,1-dimethyl-1-germabenzocyclobutene (14b) were formed in high yields, but the tin analogue was not obtained.Eight-membered ring species, the dimers 17 and 18, were isolated for all three metals.Other products gave useful indications of the probable course of these interesting and complex reactions.
- Boer, H. J. R. De,Akkerman, O. S.,Bickelhaupt, F.
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p. 291 - 306
(2007/10/02)
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