In:
Chemische Berichte, Wiley, Vol. 122, No. 12 ( 1989-12), p. 2303-2309
Abstract:
η 1 ‐C 6 H 5 CH 2 Li · THF · TMEDA, Complex with a Pyramidal Benzylic C Atom In addition to the X‐ray structure determination of C 6 H 5 CH 2 Li · N(CH 2 CH 2 ) 3 N] ∞ by Patterman, Karle, and Stucky 37 and that of [C 6 H 5 CH 2 Li ·OEt 2 ] ∞; by Beno, Hope, Olmstead, and Power 42 we present yet another benzyllithium structure: η 1 ‐C 6 H 5 CH 2 Li · THF · TMEDA ( 1 ). In contrast to the earlier ones, a monomer is observed in the case of 1 . Furthermore, in 1 lithium is only coordinated to the benzylic carbon atom whose pyramidal configuration has been determined for the first time. The molecular‐weight determination of C 6 H 5 CH 2 Li in THF giving a monomer 61 , and NMR investigations in THF indicating a pyramidal benzylic C atom in 1 (and C 6 H 5 CH 2 Li 53,54 ) correspond to the solid‐state structure of 1 . The different coordinations of lithium observed in the three solid‐state structures and the pyramidal configuration of the benzylic C atom in 1 are in agreement with theoretical studies (also of other authors 45–50 ). The pyramidal configuration of the benzylic C atom of 1 suggests that a similar stereochemical situation contributes to the high retention observed recently in Haller‐Bauer cleavage reactions of optically active benzylic ketones 62e–g .
Type of Medium:
Online Resource
ISSN:
0009-2940
DOI:
10.1002/cber.v122:12
DOI:
10.1002/cber.19891221217
Language:
English
Publisher:
Wiley
Publication Date:
1989
detail.hit.zdb_id:
779-1
