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Formation and Characterization of Zwitterionic Stereoisomers from the Reaction of B(C 6 F 5 ) 3 and NEt 2 Ph: ( E )‐ and ( Z )‐[EtPhN + =CHCH 2 ‐B − (C 6 F 5 ) 3 ]
Author(s) -
Millot Nicolas,
Santini Catherine C.,
Fenet Bernard,
Basset Jean Marie
Publication year - 2002
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/1099-0682(200212)2002:12<3328::aid-ejic3328>3.0.co;2-p
Subject(s) - chemistry , adduct , iminium , reagent , silanol , medicinal chemistry , nuclear magnetic resonance spectroscopy , stoichiometry , solvent , ionic bonding , stereochemistry , organic chemistry , ion , catalysis
The stoichiometric reaction of B(C 6 F 5 ) 3 and NEt 2 Ph I , at room temperature, in an aromatic solvent, has been investigated by 1D and 2D NMR spectroscopy ( 1 H, 11 B, 13 C, 15 N and 19 F). No Et 2 PhN·B(C 6 F 5 ) 3 adduct was observed. An equilibrium between free B(C 6 F 5 ) 3 , NEt 2 Ph, [HB(C 6 F 5 ) 3 ] − (HNEt 2 Ph) + and two zwitterionic stereoisomers ( E )‐ and ( Z )‐[EtPhN + =CH‐CH 2 ‐B − (C 6 F 5 ) 3 ] (30%) in an E / Z ratio of 3:2 was observed. Whatever the protic reagent Z‐OH [Z = H, SiPh 3 , ( c ‐C 5 H 9 ) 7 O 12 Si 8 , or silanol group of silica], all the equilibria involved in solutions of I are quantitatively displaced towards the ionic form [Z‐O ‐ B(C 6 F 5 ) 3 ] − (HNEt 2 Ph) + . In the case of dimethylaniline, besides free B(C 6 F 5 ) 3 and Me 2 NPh, the 1:1 adduct (C 6 F 5 ) 3 B·NMe 2 Ph and an iminium salt [PhCH 3 N=CH 2 ] + [HB(C 6 F 5 ) 3 ] − have been identified. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)