Tosyl group
In organic chemistry, the tosyl group is the covalently bonded residue CH 3 −C 6 H 4 −SO 2 - of p -toluenesulfonic acid . This group can be found in p -toluenesulfonic acid, the p -toluenesulfonic acid halides (example: tosyl chloride ), the p -toluenesulfonic acid esters (tosylates), the p -toluenesulfonic acid amides (toluenesulfonamides) and the p -toluenesulfonic acid hydrazides. Its name is derived from its systematic name p - To luol s ulfon yl . The tosyl group is abbreviated with “Ts”, more rarely and contrary to the IUPAC recommendations with “Tos”. The nosyl group and the brosyl group are structurally related to the tosyl group.
The tosyl group must not be confused with the tosylates , which are esters or salts of p -toluenesulfonic acid.
According to IUPAC, the term tosyl ... only refers to the para -substituted compound. For this reason, p -Ts or p -Tos should not be used as formula abbreviations .
properties
The tosyl group has an electron-withdrawing effect, which is why the underlying p -toluenesulfonic acid is a strong acid and the tosylate group is a good leaving group . This can easily be cleaved from the molecule with substitution by suitable nucleophiles . For this reason, tosyl compounds are very reactive and have a limited lifespan. This can be increased by storage in the absence of nucleophiles, for example water or alcohols.
Individual evidence
- ↑ Otto-Albrecht Neumüller (Ed.): Römpps Chemie-Lexikon. Volume 6: T-Z. 8th revised and expanded edition. Franckh'sche Verlagshandlung, Stuttgart 1988, ISBN 3-440-04516-1 , p. 4303.
- ↑ MA Brimble, D. StC. Black, R. Hartshorn, AP Rauter, C.-K. Sha, LK Syndes, Pure Appl. Chem. 2013 , 85 , 307, doi: 10.1351 / PAC-REP-12-07-12 .
- ↑ entry to tosyl .... In: Römpp Online . Georg Thieme Verlag, accessed on September 29, 2014.