Triethylammonium triflate

Reviews. Simchen et al.6 have reviewed use of trialkylsilyl triflates for silylation and as catalysts in Friedel-Crafts acylations (191 references). The review includes a method for recovery of triflic acid from the triethylammonium triflates formed in silylation in the presence of triethylamine. 

The phenolic OH group can be removed by Pd-catalysed hydrogenolysis of its triflate 522 with triethylammonium formate [261]. Naphthol can be converted to naphthalene by the hydrogenolysis of its triflate. The Ni-catalysed reduction of aryl mesylates 523 is possible using MeOH and Zn as the hydrogen donor [262]. Smooth removal of phenol groups as triflates and mesylates is not possible by any other means. 

The synthetic potential of reductions by formate has been extended considerably by the use of ammonium formate with transition metal catalysts like palladium and rhodium. This forms a safe alternative to use of hydrogen. In this fashion it is possible to reduce hydrazones to hydrazines, azides and nitro groups to amines, to dehalogenate chloro-substituted aromatics, and to carry out various reductive removals of functional groups. For example, phenol triflates are selectively deoxygenated to the aromatic derivatives using triethylammonium formate as reductant and a palladium catalyst. - These recent af li-cations have been reviewed. 

Like enol triflate, aryl triflates can be readily reduced to arenes this provides a useful general method for conversion of phenols to arenes. Chen and coworkers136 and Cacchi and coworkers137 have developed independently the reduction of aryl triflates and fluoroalkanesulfonates with triethylammonium formate in the presence of catalytic amounts of Pd(0) (equation 117). 

The reduction of aryl triflates with electron-withdrawing substituents works well also with sodium borohydride, but for systems with electron-donating substituents the use of triethylammonium formate is much better138. The method has been applied to synthesize angelicin through the sequence of equation 118. 

Polyethers 3d-e were evaluated as diemical amplification electron-beam resists. Figure 14a shows relative film thickness after development against exposed energy for the pofymer 3d containing add generator (10 wt% triphen -sulfonium triflate) after development with 0.1% aqueous triethylammonium hydroxide. Sensitivity of this pofymer as EB resist was about 300 A... 

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