Scrambling of the label in a fluorenylphosphonamidic [O-18]-sulfonate during dissociative nucleophilic substitution (elimination-addition): a measure of the importance of preassociation
When R2CHP(O)(NEt2)(OSO2Ar)-O-18 (R2CH = 9-fluorenyl, Ar = p-tolyl) undergoes nucleophilic substitution (elimination-addition) with Et2NH (0.4 mol dm(-3) in CHCl3) the phosphene intermediate R2C=P(O)NEt2 recombines with the sulfonate leaving group (internal return), causing scrambling of the O-18 la...
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Published in | Organic & biomolecular chemistry Vol. 4; no. 15; pp. 2842 - 2844 |
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Main Author | |
Format | Journal Article |
Language | English |
Published |
CAMBRIDGE
Royal Soc Chemistry
07.08.2006
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Subjects | |
Online Access | Get more information |
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Summary: | When R2CHP(O)(NEt2)(OSO2Ar)-O-18 (R2CH = 9-fluorenyl, Ar = p-tolyl) undergoes nucleophilic substitution (elimination-addition) with Et2NH (0.4 mol dm(-3) in CHCl3) the phosphene intermediate R2C=P(O)NEt2 recombines with the sulfonate leaving group (internal return), causing scrambling of the O-18 label, more quickly than it diffuses away; efficient conversion into R2CHP(O)(NEt2)(2) therefore depends on preassociation between the substrate and the nucleophile. |
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ISSN: | 1477-0520 1477-0539 |
DOI: | 10.1039/b606871e |