P-H Bond Formation and Reductions
Recent Literature
TMDS is an efficient hydride source for the reduction of tertiary and secondary
phosphine oxides using a catalytic amount of Ti(OiPr)4. All
classes of tertiary phosphine oxides, such as triaryl, trialkyl, and diphosphine
were effectively reduced.
M. Berthod, A. Favre-Réguillon, J. Mohamad, G. Mignani, G. Docherty, M. Lemaire, Synlett, 2007,
1545-1548.
Many tertiary phosphine oxides undergo considerable reduction at ambient
temperature with diisobutylaluminum hydride and then stall due to inhibition.
Source of this inhibition is tetraisobutyldialuminoxane (TIBAO), which builds up
as the reaction proceeds and selectively coordinates the TPO starting material.
Several strategies have been found to circumvent this inhibition.
C. A. Busacca, R. Raju, N. Grinberg, N. Haddad, P. James-Jones, H. Lee, J. C.
Lorenz, A. Saha, C. H. Senanayake, J. Org. Chem., 2008,
73, 1524-1531.
A new, mild protocol for deoxygenation of various phosphine
oxides with retention of configuration is described. Mechanistic studies
regarding the oxygen transfer between the starting phosphine
oxide and triphenylphosphine are also presented.
H.-C. Wu, J.-Q. Yu, J. B. Spencer, Org. Lett.,
2004, 6, 4675-4678.
