TERT-BUTYL-2,4,6-TRIMETHYLPHENYLPHOSPHINE - A CHIRAL SECONDARY PHOSPHINE WITH BULKY SUBSTITUENTS - SYNTHESIS AND NMR SPECTROSCOPIC STUDIES

摘要

The preparation and characterization of the secondary phosphine Bu(t)MesPH [Mes = 2,4,6-(CH3)(3)C6H2-], its precursor Bu(t)MesPCl, and its chalcogenides Bu(t)MesP(E)H (E = O, S, Se) are described. Their H-1, C-13 and P-31 NMR spectra are reported and show that rotation about the P-Mes bond is hindered with Delta G double dagger ranging from 56 to 88 kJ mol(-1). Two-dimensional proton ROESY spectra indicate a single preferred conformation in solution which is determined by the need to minimize the Bu(t)-Mes interaction in all cases. (C) 1997 Elsevier Science Ltd. [References: 24]