anchimericadj.
/aŋkᵻˈmɛrɪk/, /aŋkʌɪˈmɛrɪk/, U.S. /ˌænkaɪˈmɛrɪk/, /ˌænkəˈmɛrɪk/ Chemistry.
anchimeric assistance n. the participation of electrons from a functional group or bond within a molecule in a reaction at an adjacent site within the same molecule, producing an increase in reaction rate; also called neighbouring group participation.
ΘΚΠ
the world > matter > chemistry > chemical reactions or processes > [noun] > chemical reactions (general) > participation of a functional group of a molecule in
anchimeric assistance1953
1953 S. Winstein et al. in Jrnl. Amer. Chem. Soc. 75 148/1 kc is the estimated rate constant of ionization with neither anchimeric assistance nor nucleophilic assistance from solvent. [Note] This adjective (from the Greek ‘anchi’ and ‘meros’), meaning pertaining to the neighboring or adjacent part..has been suggested to us by Dr. A. P. McKinlay..for use in connection with neighboring group participation.
1964 Q. Rev. Chem. Soc. 18 45 If the transition state of a rate-determining step is stabilised in this way, an increased reaction rate results and the neighbouring group is then said to provide anchimeric assistance.
2014 M. S. Singh Reactive Intermediates Org. Chem. (e-book ed.) ii. (caption) Compound 8 reacts 1014 times faster than 7 owing to anchimeric assistance.
Derivatives
anchiˈmerically adv. by the participation of a neighbouring functional group or bond in the same molecule.
ΘΚΠ
the world > matter > chemistry > chemical structure or stereochemistry > [adverb] > characterized by functional groups
trifunctionally1941
anchimerically1953
1953 Jrnl. Amer. Chem. Soc. 75 148/1 The rate constant of solvolysis with nucleophilic solvent participation exceeds kc more than does the anchimerically assisted ionization rate.
2007 Tetrahedron Lett. 48 4072/2 The mechanism through which this product was formed must presumably proceed via the formation of the expected anchimerically stabilized cation at the bridging carbon atom.
This entry has been updated (OED Third Edition, September 2019; most recently modified version published online December 2021).
<
adj.1953