posted on 2006-02-27, 00:00authored byChangsheng Cao, Tongen Wang, Brian O. Patrick, Jennifer A. Love
In the course of our studies of the catalytic reactivity
of Tp*Rh(PPh3)2 (1), we noted considerable decomposition of
1 in reactions conducted in 1,2-dicholoroethane (DCE) requiring extended reaction times (>12 h). Because this decomposition
could have significant implications for the catalytic utility of 1,
we have undertaken a study of the decomposition process. We
herein report that 1 undergoes facile, irreversible orthometalation of a PPh3 ligand at room temperature in slightly polar
solvents, such as THF and 1,2-dichloroethane. In comparison,
orthometalation is virtually undetectable in PhCH3 at room
temperature. Fortunately, 1 shows catalytic activity for hydrothiolation and hydrophosphinylation in low-polarity solvents.
Accordingly, reactions using 1 (and potentially related complexes) should be conducted in nonpolar solvents or solvent
mixtures whenever possible.