Auration of the sulfones MeSO2 CH2CN and CH2(CH2SO2)2CH2

MeSO2CH2CN shows considerable C-H acidity at its methylene group. Through lithiation followed by reaction with (Ph3P)AuCl it can therefore be readily converted into the dinuclear, geminally substituted product MeSO2C[Au(PPh3)](2)CN. With an excess of aurating reagents, a third [(Ph3P)Au] group becomes N-bonded to the nitrile unit to give an ionic trinuclear compound {MeSO2C[Au(PPh3)](2)CNAu(PPh3)}+BF4-. The same product is obtained by direct reaction of MeSO2CH2CN with [(Ph3P)Au]BF4. The crystal structures of the two products have been determined. The diaurated sulfone parts of the molecule and the cation are virtually superimposible. Small Au-C-Au angles and short Au-Au contacts suggest significant aurophilic interactions ("A-frame" structures). The small -C N-Au angle of 165.6(5)degrees in the cation indicates that the strong [(Ph3P)Au](+) acceptor causes substantial changes in the bonding of the nitrile group. Dilithiation of 1,3-dithiane-S,S'-tetroxide followed by reaction with 2 equivalents of (Ph3P)AuCl affords the geminally diaurated compound CH2(CH2SO2)(2)C[Au(PPh3)](2).