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...

Full description

Saved in:
Bibliographic Details
Published inOrganic & biomolecular chemistry Vol. 4; no. 15; pp. 2842 - 2844
Main Author Harger, Martin J. P.
Format Journal Article
LanguageEnglish
Published CAMBRIDGE Royal Soc Chemistry 07.08.2006
Subjects
Chemistry
Chemistry, Organic
Physical Sciences
Science & Technology
CHLORIDES
MECHANISM
PHOSPHENE INTERMEDIATE
PHOSPHONAMIDIC-SULFONIC ANHYDRIDE
Online AccessGet more information

Cover

More Information
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.
ISSN:1477-0520
1477-0539
DOI:10.1039/b606871e