Triphenylcarbenium, tropylium, and other carbenium salts

The synthes of triphenjdmeth perchlorate and triphenylmethyl tetrafluoroborate have been reported.57 These reagents are obtained reaction of triphen methanol with 71% Ha04 or 48% HBF4 in the presence of acetic or propionic anhydrides (introduced to remove water), Ecp. 8.16 and 8.17  

Yields are 76% and 92% for ttie perchlorate and the tetrafluoroborate, respectively. The tetrafluoroborate, Ph3CBp4, has advantages over the perchlorate, Ph3CQ04, because of its greater stability and lack of light sensitivity.57 

It has been shown 4 that Ph3CBp4 can function as a one-electron oxidant and is able to oxidize metallic copper with formation of the homoleptic solvento-complex, [Cu(MeCN)4][BF4]. Yamazaki S has reported that the phosphine and phosphite complexes of palladium(n), [Pd(PPh3)4]X2 (X = BF4, PF, and Pd P(OPh)3 4][PF6]2, have been synthesized in 60% and 

This organic by-product was isolated in good yields during the syntheses of [Pd(PPh3)4]X2 and [Pd P(OPh)3)4][PF6h. 

In addition to the triphenylmethyl salts, other sources of carbenium ions are availaHe for use in one-electron oxidation reactions. Thus, the complex, [W(NO)2(P(OMe)3K n5-Cp)l is oxidized to the corresponding 

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