Preparation of New Sulfonated Triarylphosphanes: Control of the Selectivity by Structural Assistance

A synthetic approach for the selective preparation of tri‐, di‐, and monosulfonated triarylphosphanes is presented. PPh n Ar 3− n parent phosphanes ( 1a − 8a ) having aryl rings (Ar) activated by simple electron donating groups (CH 3 , CH 3 O) were prepared by the standard Grignard method. The activated rings could be sulfonated selectively under mild conditions and with short reaction times (0.8−3 h). Using a very simple workup procedure, the corresponding tri‐, di‐, and monosulfonated phosphanes ( 1b − 8b ) were isolated in outstanding yields (88−99%) and found to contain negligible amount of phosphane oxides (0−4%). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)