THE ACTIVATION BARRIER TO AXIAL TORSION IN 2,2'-BIS(DIPHENYLPHOSPHINO)BIPHENYL

Authors
DESPONDS O SCHLOSSER M
Citation
O. Desponds et M. Schlosser, THE ACTIVATION BARRIER TO AXIAL TORSION IN 2,2'-BIS(DIPHENYLPHOSPHINO)BIPHENYL, Tetrahedron letters, 37(1), 1996, pp. 47-48
Citations number
8
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Tetrahedron letters → ACNP
ISSN journal
00404039
Volume
37
Issue
1
Year of publication
1996
Pages
47 - 48
Database
ISI
SICI code
0040-4039(1996)37:1<47:TABTAT>2.0.ZU;2-5
Abstract
After selective deuteriation of 2,2'-bis(diphenylphosphino)biphenyl, i t was possible to determine the nmr coalescence temperature of the dia stereotopic phenyl groups. On this basis, a torsional barrier of 22 kc al/mol was calculated. Thus, the bisphosphine, even if it could be res olved into pure cnantiomers, would rapidly reracemize at temperatures around or above 25 degrees C.